What is the severity of injuries associated with electric scooters (e-scooters) compared with motorbikes or bicycles?In this cohort study of 5233 patients referred in a major trauma center, injuries due to e-scooters were as severe as those due to bicycle or motorbike crashes. The mortality associated with e-scooter road traffic crashes was 9.2%, compared with 10.0% for bicycles and 5.2% for motorbikes.The findings of this study may inform health care professionals of the specificities of major trauma related to e-scooters and inform future e-scooter regulation decisions worldwide. Electric scooter (e-scooter) use is increasing in France and in many urban environments worldwide. Yet little is known about injuries associated with use of e-scooters.To describe characteristics and outcomes of major trauma involving e-scooters.A multicenter cohort study was conducted in France using the national major trauma registry between January 1, 2019, and December 20, 2022. All patients admitted to a participating major trauma center following a road traffic crash (RTC) involving an e-scooter, a bicycle, or a motorbike were included.Included patients were compared according to the 3 mechanisms.The primary outcome was trauma severity as defined by the Injury Severity Score (ISS). Secondary outcomes included the trends of the number of patients per year, a comparison of the RTC epidemiologic factors, injury severity, resources used, and in-hospital outcomes.P = .10) and bicycle RTCs . With a proportion of 25.9% (n = 50), patients with e-scooter RTCs had twice as many severe traumatic brain injuries  as motorbike RTCs (445 [11.8%]) and a proportion comparable to bicycle RTCs (174 [22.1%]). The mortality of e-scooter RTCs was 9.2% (n = 20), compared with 5.2% (n = 196) (P = .02) for motorbikes and 10.0% (n = 84) (P = .82) for bicycles.A total of 5233 patients involved in RTCs were admitted . The population included 229 e-scooter RTCs (4.4%), 4094 motorbike RTCs (78.2%), and 910 bicycle RTCs (17.4%). The number of patients treated following e-scooter RTCs increased by 2.8-fold in 4 years (from 31 in 2019 to 88 in 2022), while bicycle RTCs increased by 1.2-fold and motorbike RTCs decreased by 0.9-fold. At admission, 36.7% of e-scooter users had a blood alcohol content higher than the legal threshold (n = 84) and 22.5% wore a protective helmet (n = 32). Among e-scooter RTCs, 102 patients (45.5%) had an ISS of 16 or higher. This proportion was similar for patients with motorbike RTCs (1557 [39.7%]; The findings of this study suggest that trauma involving e-scooters in France has significantly increased over the past 4 years. These patients presented with injury profiles as severe as those of individuals who experienced bicycle or motorbike RTCs, with a higher proportion of severe traumatic brain injury. This cohort study compares the incidence and severity of trauma-related injuries in patients who experienced road traffic crashes while using electric scooters, motorbikes, and bicycles in France. This report focused on injuries sustained by e-scooter users based on expert audits, scientific publications, national road safety reports, and press articles. The report nevertheless focused mainly on single-center case series, which did not allow for a precise description of patients with the most severe injuries.The French Academy of Medicine recently published a report2Since 2012, the French Observatory for Major Trauma has developed the TraumaBase national registry. This registry includes all individuals with major trauma who are admitted to 1 of more than 20 major trauma centers and has collected data on nearly 50 000 patients. The participating major trauma centers are identified by the Regional Health Agencies as being within their respective geographic areas, the first-line resource for caring for individuals with the most severe injuries, whether in the context of road crashes, falls, assaults, or mass casualty situations.This registry collects descriptive data on the crash and prehospital and in-hospital evaluation data for all patients admitted after a severe trauma. This information allows for a very precise characterization of the person’s injuries and their effect on vital functions. The registry also includes information on the care provided, which gives an idea of the resources necessary for care at the patient, center, and regional level. In addition, the registry describes the in-hospital outcome of each patient, including survival and/or the occurrence of the most serious complications. This information is a valuable resource for describing the morbidity and mortality associated with severe trauma in France. Aware of the importance of e-scooters in public health, the registry has integrated the involvement of e-scooters in the mechanisms of crashes since 2019.We therefore sought to provide original data from a large national registry to describe RTCs involving e-scooters. We especially hypothesized that these crashes result in injuries at least as severe as those caused by RTCs involving other vehicles, such as bicycles or motorbikes.The objective of this work was to describe the epidemiologic characteristics of e-scooter RTCs over time in France; document the baseline characteristics of individuals with e-scooter injuries, their in-hospital management, and their outcomes; and compare them with those of patients with an RTC involving bicycles or motorbikes.STROBE) reporting guideline.We conducted a multicenter cohort study using data from the French National Trauma Registry (TraumaBase) from January 1, 2019, to December 20, 2022. A total of 26 trauma centers in France participated in the data collection. All data were collected as part of patient care, and no data were collected specifically for this project; data are deidentified. The TraumaBase registry has been approved by the Consultative Committee on the Processing of Health Research Information and the French National Commission on Informatics and Liberty. This study follows the Strengthening the Reporting of Observational Studies in Epidemiology  of 16 or higher was considered a marker of severe injuries.7We defined a severe traumatic brain injury as a Glasgow Coma Scale score of 8 or less at initial assessment.7 An AIS score greater than or equal to 3 indicated the presence of at least 1 severe injury in the area of interest.The Abbreviated Injury Scale (AIS) was used to describe each injury and its degree of severity (from 0 meaning no injury to 6 meaning unsurvivable injuries) within 6 body regions.8 The TRISS can be compared with the mean observed mortality at the population level as proposed by the American College of Surgeons Trauma Quality Improvement Program to determine excess mortality.9The ISS, when completed with information such as vital functions, age, and mechanism, allows for the calculation of the Trauma and Injury Severity Score (TRISS), which predicts mortality at the individual patient level and can thus provide a predicted mortality at a population level.10The body topography of the injuries was characterized using the precise AIS codes used to capture each injury. From these AIS codes, all codes beginning with the number 7 were associated with upper extremity injuries and all codes beginning with the number 8 were associated with lower extremity injuries.The primary outcome was the severity of trauma as defined by the ISS. Secondary outcomes included comparisons across the 3 groups of the trends of the number of patients per year, RTC epidemiologic factors , clinical and injury severity , in-hospital resources used , and in-hospital outcomes .We compared patients involved in e-scooter RTCs with bicycle and motorbike RTCs. This comparison was relevant because bicycles and motorbikes are typically included in studies involving patients who have experienced major trauma. Furthermore, all 3 devices involve falls from unenclosed 2-wheeled vehicles. These RTCs may or may not be preceded by a collision or followed by a crash.2 tests were used for categorical variables and nonparametric Kruskal-Wallis tests were used for continuous variables.Continuous variables are reported as medians (IQRs), while categorical variables are reported as numbers and their relative percentages. To compare the participants according to the mechanism , χMissing data were not imputed, except for the BAC, which was missing for nearly 30% of patients. To this end, a multiple imputation was conducted using variables that were found to be associated with the BAC in univariate analysis to complete the missing data.P value <.01 was considered significant to account for α risk inflation. All analyses were performed using R, version 1.4.1106 software .A A total of 20 172 patients were included in the TraumaBase registry; of these patients, 5233  met the inclusion criteria. Among these patients, 229 were treated following e-scooter RTCs, 4094 following motorbike RTCs, and 910 following bicycle RTCs. Among e-scooter RTCs, 161 patients (70.3%) were treated in 1 of the 6 trauma centers in the Paris urban region.The annual number of RTCs was stable over time , A. DespThere was a fluctuation in the number of admissions for e-scooter RTCs both weekly  years. This was similar to motorbike users, whose median age was 31  years, while bicycle users were significantly older, with a median age of 48  years . Most ofP < .001). The sensitivity analysis, acknowledging missing data (27.5%) by using multiple imputation, highlighted that the BAC at the time of admission was above the 0.5-g/dL threshold in at least 22.5% (n = 923) of motorbike cases, 9.8% (n = 89) of bicycle cases, and 36.7% (n = 84) of e-scooter cases  in 20.7% of motorbike (n = 626), 10.8% of bicycle (n = 66), and 28.9% (n = 48) of e-scooter users (er cases .P = .39). Age also appeared to be associated with helmet use, with helmets worn in 20.5% (n = 24) of the cases by those younger than 50 years and in 32.0% (n = 8) of those older than 50 years (P = .33). This analysis of helmet use was marked by a large proportion of missing data, with nearly 53% of data not reported.Regarding helmet use at the time of the crash, individuals with e-scooter RTCs were half as likely as bicycle users to wear a helmet (22.5% [n = 247] vs 49.3% [n = 22]). Men wore a helmet in 24.8% (n = 28) of the crashes compared with 14.8% (n = 4) for women (P = .46). The proportion of severe traumatic brain injuries among patients with e-scooter RTCs (50 [25.9%]) was significantly higher than in patients with motorbike RTCs (45 [11.8%]) and similar to that of patients with bicycle RTCs (17 [22.3%]) (both P < .001)  of patients with e-scooter RTCs, which did not differ significantly from that of patients with motorbike (911 [22.3%]) or bicycle (203 [22.3%]) RTCs ( < .001) .P = .10) and bicycle RTCs  (P < .001) and similar to patients with bicycle RTCs   . The anaP = .18) . All 3 RP = .18) .P = .02) and 26.3% (n = 227) for bicycle RTCs (P = .57) (P = .01) and 8.4% (n = 50) for bicycle RTCs (P = .13). At 24 hours, 66.7% (n = 152) of the patients with e-scooter RTCs required at least 1 intervention compared with 73.7% (n = 2977) for motorbike RTCs and 55.7% (n = 501) for bicycle RTCs  of patients with e-scooter RTCs compared with 17.8% (n = 714) for motorbike RTCs (P = .57) . The patcle RTCs .P < .001). Likewise, in-hospital lengths of stay were 6  days for e-scooter RTCs, 8  days for motorbike RTCs, and 7  days for bicycle RTCs (P = .03)  days for e-scooter RTCs, 2  days for motorbike RTCs, and 3  days for bicycle RTCs (P = .03) .P = .82) and 5.2% (n = 196) for motorbike RTCs (P = .02). Traumatic brain injury was the leading cause of death for all 3 groups, accounting for 65.0% (n = 13) of deaths among e-scooter RTCs, 38.3% (n = 75) among motorbike RTCs, and 63.1% (n = 53) among bicycle RTCs , compared with 10.0% (n = 84) for bicycle RTCs ; and South Korea, while, at the opposite end of restrictions, Japan has lightened its regulations.The risk of craniofacial injuries is known for e-scooter RTCs,21 This report also points out that a significant proportion of patients with RTCs admitted to a major trauma center had consumed alcohol. These findings are in line with those presented in several single-center studies conducted in emergency departments in Europe.22We could not confirm the predominance of upper extremity injuries compared with lower extremity injuries in our population of patients with major trauma, while several studies had raised this point.24We acknowledge some potential limitations. First, the registry does not cover all centers in France, nor does it cover every hospital facility that admits trauma patients in each region (only major trauma centers). For these reasons, the undertriage rates for each population could not be reported and this study’s results should not be treated as an exhaustive picture of e-scooter RTCs in France, although it provides what is, to our knowledge, the largest description of patients with major trauma experiencing an e-scooter RTC reported in the literature. Similarly, we were unable to provide an aggregate count of the daily users of e-scooters within each trauma center area, as well as those involved in a crash, regardless of whether they sustained injuries during the inclusion period. However, a recent marketing study in France estimated that sales for e-scooters increased from €220 million (US $236 million) to €373 million (US $400 million) from 2019 to 2022 (70%) and the increase in the number of e-scooters for hire has already been linked to an increase in the number of hospital admissions.25Second, it appears that individuals with e-scooter RTCs tend to have more severe injuries  than those with motorbike RTCs. This could illustrate an overtriage of motorbike RTCs due to the frequent presence of a high kinetic criterion, which prompts prehospital physicians to refer these patients to a major trauma center even when the clinical assessment is reassuring. In contrast, patients with e-scooter RTCs, who are perceived as moving more slowly, do not benefit from this criterion and could therefore be at risk of undertriage. This underestimation of e-scooter RTCs was reported recently in an original study involving natural language processing conducted in Los Angeles.26 This accompanies strong evidence that major trauma involves substantial long-term morbidity issues, with patients frequently developing problems such as chronic pain, difficulty walking, difficulty returning to work, or mental health impairment.28 The similarity between injuries encountered by patients with e-scooter RTCs and those of other RTCs suggests that these patients are very likely to be confronted with this burden.Third, the TraumaBase register does not collect some important information, such as vehicle speed, crash cause and description, socioeconomic status of the user, health status at the time of discharge (including the place of discharge and the autonomy), or long-term health consequences. These results, in conjunction with the findings of this study, could have been useful, especially within the context of possible changes in legislation regarding e-scooters in several countries. The question of long-term outcomes appears to be a great opportunity for development, especially given the fact that patients with major trauma appear to have a 3 times higher postdischarge 3-year mortality rate than other adults.This cohort study provides insight from major trauma centers in France into the types of injuries associated with the growing use of e-scooters. It highlights a significant increase in the admission rate of patients with severe injuries due to e-scooter RTCs over the past 4 years. It also points out that these crashes appear to result in injuries as severe as those seen with bicycle or motorbike RTCs with a higher rate of severe traumatic brain injury and greater concern about risky behaviors. This study could provide meaningful information for stakeholders involved in regulating the use of these devices in France.


Very scanty evidence is available on factors influencing the choice of immunosuppressive drug therapy after kidney transplantation.An Italian multiregional real-world study was conducted integrating national transplant information system and claims data. All patients undergoing kidney transplantation for the first time during 2009–2019 (incident patients) were considered. Multilevel logistic models were used to estimate Odds Ratio (OR) and corresponding 95% Confidence intervals. Factors with statistically significance were identified as characteristics associated with treatment regimens: cyclosporin-CsA vs tacrolimus-Tac and, within the latter group, mTOR inhibitors vs mycophenolate-MMF.We identified 3,622 kidney patients undergoing transplantation in 17 hospitals located in 4 Italian regions, 78.3% was treated with TAC-based therapy, of which 78% and 22% in combination with MMF and mTOR, respectively. For both comparison groups, the choice of immunosuppressive regimens was mostly guided by standard hospital practices. Only few recipient and donor characteristics were found associated with specific regimen .The choice of post-renal transplant immunosuppressive therapy seems to be mostly driven by standard Centre practices, while only partially based on patient’s characteristics and recognized international guidelines.The online version contains supplementary material available at 10.1186/s12882-023-03325-9. During the past two decades, the introduction of new immunosuppressive drugs has represented the key to the success of solid organ transplantation. Several immunosuppressive agents block specific mechanisms underlying the adaptive response. Standard immunosuppression protocol for maintenance phase consists of calcineurin inhibitors “CNI” (Cyclosporine “CsA” or Tacrolimus “Tac”) with antimetabolite (Mycophenolate “MMF” or Azathioprine “Aza”) or mTORi (Everolimus “EVE” or Sirolimus “SIR”) plus corticosteroids, mainly Prednisone “PRED” , 2. AlthA recent article shows a high heterogeneity of the immunosuppressive drug combinations employed in the maintenance phase of solid organ transplantation in the Italian context ., are poorly investigated. The choice of therapy should take into account both the efficacy to prevent graft rejection and potential long-term side effects, so that demographic and clinical characteristics of donor and graft recipient should drive the choice of treatment [The possible reasons for choosing a certain regimen of immunosuppressive therapy over other schemes in terms of type or number of active agents prescribedreatment , 6.Furthermore, the choice of immunosuppressive regimen may vary across hospitals; instead, so a thorough evaluation of patients’ characteristics should drive the immunosuppressant regimen on the basis of a multilevel approach .The aim of our study was to assess recipient, donor and transplant characteristics associated with immunosuppressive maintenance strategy in a kidney transplant cohort across four Italian districts (regions), taking into account the local hospital’s policies.The Shiniss”. The study design, health information flows used, the institutional framework, record-linkage procedures are described in more detail elsewhere [A retrospective observational study on determinants related to drug utilization patterns in a cohort of kidney transplant patients, resident in 4 Italian regions  was performed. The transplant patients’ cohort was identified through data available in regional administrative healthcare databases linked to national transplant information system (SIT) using a common data model and an open-source tool for distributed analyses, “lsewhere .Briefly, the study included all patients who underwent incident kidney transplant in the years 2009–2019, surviving 30 days after discharge, with at least one immunosuppressive dispensation in the maintenance phase after hospital discharge. Patients with previous immunosuppressive treatment were excluded. The complexity of the treatment regimens is schematized in the Fig. index therapy), patients treated with CNI therapies were identified. More specifically, therapeutic regimen groups were classified in CsA- or Tac-based therapies, considered alone or in combination with other active agents, i.e. MMF or mTORi with/without PRED. With respect to the use of antimetabolite drugs together with Tac, the focus in this paper is mainly on the comparison with MMF since, in the renal setting, the frequency of combination of Azathioprine (AZA) with Tac is low [Based on the dispensation retrieved during the 30 days after transplant discharge (c is low .st comparison group) and Tac + mTORi vs Tac + MMF (2nd comparison group).Patterns of use of immunosuppressive drugs have been described in details in a previous article . In thisIn addition to the contextual variables like hospital where the transplant has been performed, year of discharge, length of stay during index hospitalization, the following covariates related to recipient were tested as factors potentially related to immunosuppressive therapy: sex, age, cardio-cerebrovascular disease, respiratory diseases, tumors, thyroid gland disorders, diabetes, lipid metabolism disorders and obesity, hematologic diseases, hypertension. From SIT, we tested variables of clinical interest: transplant indications, type of dialysis, the distance between first dialysis and transplantation. Moreover, panel reactivity antibodies (PRA), a test to detect preformed recipient antibodies through the use of a panel of typifying cells and the number of mismatches, a target categorical variable denoting the level of compatibility between donor and recipient.With respect to donor characteristics, we explored sex, age, type of donor (deceased/living), previous infections and malignancies.In detail, data sources, time windows and criteria used to define covariates can be found in a previous article .sunburst charts. We described the most frequent combinations of immunosuppressive drugs administered to patients and underlined the two comparison groups of interest . Treatment groups represented the dependent variable in the analyses.Maintenance immunosuppressive treatment regimens were plotted using Clinical, demographic and contextual variables were presented separately between the two comparison subgroups as column-wise frequencies and percentages for categorical variables and mean/median for continuous variables. Only variables with a threshold frequency above 5% in the overall cohort were considered.In order to evaluate the role of transplant centers in the choice of drug therapy, the proportion of patients treated with the various immunosuppressive combinations was stratified by transplant center.st comparison and Tac + mTORi versus Tac + MMF in the 2nd comparison between clusters, in this case between different hospitals of discharge [Considered the hierarchical data structure, patients are nested within hospitals, a logistic multilevel model was performed in order to account for potential intra-class correlation and to consider the clustered nature of the data. Moreover, our goal was to investigate sources of variations within- and between-clusters, to describe variables predicting individual differences and to describe which variables predict cluster-level differences . The varischarge . The MORischarge . This meA MOR equal to 1.00 indicates no variability between clusters; as the variability between group increases, the value of the measure increases.In the first step, in order to quantify the crude variability of treatment choices among hospitals performing transplants, the MOR was estimated using an intercept-only model. In a second step, the MOR was estimated controlling for patient characteristics, in order to ensure that different composition of patients within groups  did not influence estimates of variance.Age and sex of receiving patient were considered as a priori determinants of the drug therapy choice, others factors were selected by stepwise logistic regression methods. For both comparisons, a multilevel model  was applied to identify determinants of index therapy, after correction for variability between hospitals.The model's ability to predict treatment patterns by taking into account, separately and together, hospital and individual patient characteristics was evaluated through the Receiver Operating Characteristic (ROC) curve . In partData management and statistical analyses were carried out using Sas software .After applying exclusion criteria and identifying index therapy administered to patients Figure S, the cohAmong patients receiving Tac-based index therapy, 559 22.0%) were treated in combination with mTORi. Through sunbursts graphs  and, among patients treated with Tac, belonging to the 2nd comparison (mTORi vs MMF)  Fig. .Fig. 3Hep-value 0.005). Comparing mTORi vs MMF, the proportion of patients treated with mTORi in the Tac-based subpopulation varies from 0% to 65.9%. The crude MOR is 6.78 .Comparing CsA vs Tac, the proportion of patients treated with CsA in the cohort ranges from 0% to 99.6%, with a further regional gradient easily discernible in the graph. In support of that, the MOR calculated taking into account only the intercept is 10.2   and TAC users (54 years); the proportion of living donors appears to be significantly higher for patients starting therapy on CsA (13.3%) than for those treated with Tac (2.3%). In relation to clinical information retrieved from SIT, among dialysis-treated patients, CsA-treated patients are more likely to be associated with a dialysis course longer than 24 months (CsA 76.3% vs Tac 67.6%). The variable 'number of mismatches' shows a different distribution of coding classes, particularly in the '0' class (CsA 7.4% vs Tac 17.0%) and the '3–4' class (CsA 68.9% vs Tac 56.0%).Concerning patients treated with CsA, there is a higher proportion of inpatients treated over a prolonged period of time during the index hospitalization (CsA 26.6% vs Tac 22.5%). It can be seen that over time, the proportion of patients with index therapy in Tac increased .Furthermore, patients treated with Tac show a higher prevalence of comorbidities such as respiratory diseases (CsA 8.3% vs Tac 11.5%) and thyroid gland disorders (CsA 9.4% vs Tac 13.9%); there is a different concomitant use for some drug categories, such as anti-anaemic drugs (CsA 36.7% vs Tac 53.7%).nd comparison group (Tac-based therapies with addition of other immunosuppressors), a higher median age of the recipient patient and donor is shown in mTOR user . The proportion of living donors appears to be significantly different (mTORi 1.3% vs MMF 16.9%).In the 2The proportion of patients treated with high PRA (80 +) was higher among patients treated with mTORi (4.2% vs 1.3%). The variable 'number of mismatches' showed a different distribution of coding classes, particularly in the '3–4' class (mTORi 51.1% vs MMF 57.0%).With respect to the patient's clinical history, a different proportion of patients with cardio-cerebrovascular disease (mTORi 23.6% vs MMF 19.2%) and diabetes (mTORi 17.0% vs MMF 11.9%) emerged. With regard to additional drugs used, we observed different proportions of patients treated with antiplatelet (mTORi 40.4% vs MMF 30.7%) and statins (mTORi 44.7% vs MMF 30.7%).The multivariable models show factors associated with maintenance immunosuppressive therapies, net of explained variability by transplant centers Fig. a, b.Fig.st comparison group (CsA vs Tac), the effect of age of donor was clear with respect to the reference category (age less than 30 years): prescription of Tac increased in the age group’30–59’ years  and further in the group’60 + ’ years . Increasing the “number of mismatches” is a determinant of immunosuppressive therapy with Tac , like having “PRA” + 80 . A contextual factor determining CsA-based index therapy is the length of the index hospitalization in which the transplant is performed . More recent years are increasingly related with a greater use of Tac . In the supplementary materials, an area graph makes it possible to visualise the variation over time of the proportion of patients treated with the immunosuppressors of interest . The applied model considering both facility and patient characteristics, achieve a high level of patient classification to therapy (AUC = 0.94) . After controlling for patients’ characteristics, we detected variation between hospitals . The effect of age of receiving was clear, with respect to the reference category (age less than 30 years): being treated with mTORi increased in the age group’30–59’ years  and further in the group’60 + ’ years , despite reducing the accuracy of the estimate. Contextual factors such as prolonged-hospitalization after transplant  and recent years  are related with a greater use of MMF. After controlling for patients’ characteristics, we detected a clear variation among hospitals . The applied models, considering both hospital level and patient characteristics, achieve a satisfactory level of patient classification to therapy (AUC = 0.88) ; moreover, misclassification of the index therapy could be due to a lack of available data on out-of-pocket drug purchase and on the drugs dispensed at the hospital level, during the post-transplant hospitalization.Furthermore, reasons behind specific treatment protocols implemented by individual discharge hospitals cannot be quantified by current administrative flows.Although this analysis covers four major Italian regions, among which the two most populated (÷ 16.000.000 inhabitants), it may not be fully representative of the actual clinical practice nationwide.Our results show that immunosuppressive regimens applied to kidney transplant patients in the immediate post-discharge period are fairly heterogeneous, seems to be mostly related to standard practices of centers in charge of the patient. However, some recipient and donor characteristics emerge from the analyses: further research could be useful to investigate the underlying reasons of it and whether other factors, not detectable through current data flows, may better explain this phenomenon.Additional file 1: Figure S1. Flow chart.Additional file 2: Figure S2. Proportion of patients treated with immunosuppressive therapies over time.Additional file 3: Figure S3. . ROC curves by comparison groups.Additional file 4: Table S1. A-B. Determinants related to index therapy: CsA vs TAC, Tac+ mTORi vs TAC+MMF (selection period 2014-2019).


The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults.A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011–2020). Functional disability was ascertained using the national database of Japan’s Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants’ waists.p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability . No significant association was observed between sedentary bout length and functional disability.During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios  of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.The online version contains supplementary material available at 10.1186/s12966-023-01490-6. Functional disability such as limitations on activities of daily living (ADL) and instrumental activities of daily living (IADL) among older adults causes increased acute care use , hospitaCompelling evidence has shown that engaging in moderate-to-vigorous intensity physical activity (MVPA) protects against functional disability –7. ExcesAlthough some evidence suggests that the health impact of sedentary time is independent of MVPA –11, 16, This study used a 9-year prospective design and aimed to investigate 1) whether total sedentary time or prolonged bouts of sedentary time are associated with the risk of incident functional disability in a cohort of community-dwelling older Japanese adults; and 2) whether replacing sedentary time with MVPA and/or LPA is associated with reduced risk of incident functional disability.n = 2,629). For this analysis, we excluded nine participants who were certified as requiring LTCI before their baseline measurements. We further excluded 15 participants with a self-reported medical history of dementia or Parkinson’s disease, 858 participants without valid accelerometer data, and 60 participants without complete data on covariates, resulting in an analytic cohort of 1,687 participants  on either side of their waist for 7 consecutive days when awake (removing it for any water-based activities) , 27. NonThe cutoff points for activity intensity used to define sedentary time, LPA, and MVPA were ≤ 1.5 METs, 1.6–2.9 METs, and ≥ 3 METs. A bout of sedentary behavior was defined as consecutive minutes of activity intensity ≤ 1.5 METs without interruption. Total sedentary time was defined as the total accumulated time spent in all bouts of sedentary behavior. Mean sedentary bout length was calculated as total sedentary time divided by the number of bouts. Higher bout length indicates more prolonged accumulation patterns, whereas lower bout length indicates interrupted patterns. The two measures of sedentary time, LPA, and MVPA were averaged across valid days and expressed in min/day.2). Multimorbidity was defined as the presence of two or more of 13 chronic diseases: hypertension, stroke, heart disease, diabetes mellitus, hyperlipidemia, respiratory disease, digestive disease, kidney disease, osteoarthritis or rheumatism, trauma fracture, cancer, ear disease, and eye disease. The presence of chronic diseases was self-reported via the questionnaire. Cognitive function was measured using the Japanese version of the Mini-Mental State Examination (MMSE). MMSE scores range from 0 to 30 points, with higher scores indicating better global cognitive function. Cognitive impairment was defined as an MMSE score < 24 points ), medians (interquartile range [IQR]), or proportions across the quartiles of total sedentary time, as appropriate. Trends of characteristics across quartiles of total sedentary time were tested using the Jonckheere-Terpstra trend test for continuous variables and the Cochran–Armitage trend test for categorical variables.Given the strong correlation between total sedentary time and accelerometer wear time  and 95% confidence interval (CI) of functional disability by quartiles of total sedentary time and mean sedentary bout duration. Model 1 was adjusted for sex and age. Model 2 was additionally adjusted for education, living alone, BMI, multimorbidity, fall experience in the past year, low walking ability, cognitive impairment, smoking, and drinking. Trends in functional disability risk across the quartiles of total sedentary time and mean sedentary bout duration were tested by assigning ordinal numbers  to each quartile and treating the quartiles as a continuous variable.To test the independent effect of sedentary time and patterns from MVPA , 16, we We used the isotemporal substitution model to account for the codependence of sedentary time and physical activities, and to estimate the theoretical effects of replacing 10 min of sedentary time with equal time of LPA or MVPA . For a cWe conducted a sensitivity analysis by adjusting for accelerometer wear time as a covariate instead of the residual method used to correct for accelerometer wear time. To account for potential reverse-causation bias, we performed two sensitivity analyses by excluding 1) individuals who developed functional disability within the first 2 years of follow-up (n = 113), and 2) individuals who did not normally walk continuously for 15 min at baseline (n = 212). All statistical analyses used SAS version 9.4 . The significance level was set at two-sided α = 0.05.Participants’ mean age at baseline was 73.3 (SD 6.0) years and 62.2% of participants were women. The mean accelerometer wear time was 839.1 (SD 105.3) min/day. On average, participants spent 462.3 (SD 125.4) min/day  sedentary, 332.0 (SD 98.0) min/day  on LPA, and 44.8 (SD 34.4) min/day  on MVPA. The mean sedentary bout length was 8.2 min (SD 3.2). Table P for trend = 0.01). The mean sedentary bout length was not significantly associated with the risk of functional disability in either model. After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability . The association of total sedentary time and mean sedentary bout length with risk of functional disability did not vary by MVPA levels, age groups, or sex .During a median follow-up of 8.8 (IQR 6.0–8.8) years and 12,185 person-years, 466 participants developed functional disability, 129 died before experiencing any functional disability, and 85 moved out of town. Table P for linear = 0.01; P for nonlinear = 0.22)  .Cubic spline analysis showed that total sedentary time was associated with the risk of functional disability in a linear dose–response manner  of 1.00 (0.99–1.02) for functional disability. However, the replacement with 10 min of MVPA was significantly associated with a 12% lower risk of functional disability  and has been shown to underestimate the actual MET of activities among older adults, particularly for more intense activity of 3 MET or higher . TherefoThis study suggests that higher levels of total sedentary time were associated with an increased risk of incident functional disability; however, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with a reduced risk of functional disability. While recent physical activity guidelines recommend that older adults should limit the amount of time spent being sedentary, our findings suggest that promotion of MVPA should still be prioritized to reduce the risk of functional disability.Additional file 1. The distribution of age, gender, and education in Sasaguri Town and in Japan as a whole.Additional file 2. Characteristics of included participants versus excluded participants due to without valid accelerometer data in present study.Additional file 3. STROBE Statement—Checklist of items that should be included in reports of cohort studies.Additional file 4. Restricted cubic splines for the association between total sedentary time and risk of functional disability.Additional file 5. Hazard ratios for the risk of functional disability by total sedentary time and mean sedentary bout duration quartiles adjusting for the accelerometer wear time directly.Additional file 6. Hazard ratios for the risk of functional disability by total sedentary time and mean sedentary bout duration quartiles after excluding participants certified as functional disability in the first two year of follow-up .Additional file 7. Multivariable-adjusted hazard ratios of functional disability associated with 10-min changes in time spent in sedentary, LPA, and MVPA after excluding participants certified as functional disability in the first two year of follow-up .Additional file 8. Hazard ratios for the risk of functional disability by total sedentary time and mean sedentary bout duration quartiles after excluding participants who did not normally walk continuously for 15 min at baseline .Additional file 9. Multivariable adjusted hazard ratios of functional disability associated with 10-min changes in time spent in sedentary, LPA, and MVPA after excluding participants who did not normally walk continuously for 15 min at baseline .


Chronic neck pain (CNP) substantially impacts quality of life, posing both personal challenges and economic strains. This systematic review sought to discern muscle-specific stiffness differences between CNP patients and individuals without CNP.We searched the PubMed, Scopus, and PEDro databases for studies using ultrasound elastography or myotonometry to compare muscle stiffness between CNP patients and asymptomatic controls. Using a meta-analysis with a random-effects model, we derived the pooled effect as standardized mean difference (SMD).p = 0.03; small effect size). The data for other muscles remained inconclusive.Out of the six studies selected, the adjusted Newcastle-Ottawa rating scale for cross-sectional studies denoted three as moderate-quality and three as high-quality. Our findings indicate that the upper trapezius (UT) stiffness was elevated in CNP patients compared to their counterparts without CNP (SMD = 0.39, 95% CI = 0.05 to 0.74; Given the case-control design of all reviewed studies, a direct causative link between UT stiffness and CNP is yet to be confirmed. As such, recommending a reduction in trapezius muscle stiffness as a primary rehabilitation strategy for CNP patients is still inconclusive and further research is needed. With While CNP patients often subjectively report increased neck stiffness , 20, objRecent research indicates heightened stiffness in several neck muscles among CNP patients. For example, Taş et al.  found in2.A systematic review was performed to identify randomized clinical trials exploring the differences in muscle stiffness between patients with CNP and asymptomatic control groups. This review was executed in line with the guidelines established by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) .2.1.We considered case-control cross-sectional studies that compared muscle stiffness between idiopathic CNP patients with pain lasting >3 months and a matched asymptomatic control group. Experimental studies involving both CNP patients and an asymptomatic control group were also considered, with only baseline data being retrieved. Studies were excluded if participants suffered from specific pathologies associated with CNP, such as migraines or myofascial syndrome. Regarding the muscle stiffness outcomes, we considered ultrasound elastography and myotonomtery. Segment or joint-level stiffness assessments  were not considered, as our research question was focused on stiffness changes in specific muscles. Aiming to offer a comprehensive review, we incorporated both passive (relaxed muscle) and active (contracted muscle) stiffness outcomes. We then performed subgroup and sensitivity analyses to discern if the differences between CNP patients and the control group were contingent upon the stiffness measurement type. Inclusion criteria included original articles, either full-length or brief communications, published in peer-reviewed journals. While our database search didn't restrict based on language or publication date, only English articles were selected for data extraction.2.2.neck pain” OR “neck syndrome” OR “cervical pain”) AND (muscle stiffness OR muscle tone OR elastography OR myotonometry). During the manuscript revision stage (August 2023), additional MeSH terms “muscle tonus” and “Elasticity Imaging Techniques” were added to the search string, with no additional papers identified. In the PEDro database, a simple search was used with individual combinations of words, such as “neck pain stiffness”, “muscle stiffness neck” “elastography neck pain” and “myotonometry neck pain” were used. While Scoups and PEDro databases were also explored for studies that used terminology similar to the specified MeSH terms, it has to be recognized that they do not utilize PubMed's MeSH terms or subject headings. In addition, we (1) reviewed the reference lists of identified systematic reviews on the topic (2) reviewed the reference lists papers already obtained through the abovementioned databased (3) performed an additional non-systematic search of the Google Scholar search engine with the same key words as used in PEDro database. The records were imported into Mendeley (version 1.19.8) to remove the duplicates, and then exported into Microsoft Excel software for further steps. After the duplicates were removed, the authors examined the titles and abstracts, and excluded the studies that obviously did not fit the research question. In case there was a disagreement between the authors, the paper was carried over to the next stage. Then, a full-text examination was performed, and data extraction was performed for the articles that met the exclusion criteria. The reasons for exclusions were noted and listed in the PRISMA flowchart  muscle stiffness figures for CNP and control groups, including means and standard deviations; (b) demographic details such as gender, age, height, weight, and body mass index; (c) specifics of the measurement processes, including the device used, type and units of the outcome measure, measurement location, and participant's posture.All data were organized using Microsoft Excel 2016 . When data was solely presented graphically, we utilized the GetGraphDataDigitalizer software (version 2.26.0.20) to extract the means and standard deviations. For any instances of incomplete data, we reached out to the respective article authors via email and ResearchGate. If there was no communication 14 days post the second reminder, we deemed the data as irretrievable.2.4.We employed the Newcastle–Ottawa quality assessment scale for Cross-Sectional studies  to evalu2.5.I2 statistics, following the Cochrane guidelines . The threshold for statistical significance was set at p ≤ 0.05 for the pooled effect size. In case of substantial heterogeneity between the studies, a sensitivity analysis was performed by examining the effect of exclusion of studies that differed significantly from the pooled effect.The meta-analysis was conducted in Review Manager . There is no consensus on the minimal number of studies required for a meta-analysis , therefo3.3.1.The literature search is summarized in 3.2.The muscles represented were upper trapezius (6 studies), levator scapulae (3 studies), sternocleidomastoideous (2 studies), splenis capitis (2 studies), multifidus (2 studies), semispinalis capitis (1 study), rhomboid major (1 study) and semispinalis cervicis (1 study). All studies included adult population (range of means for age: 24.5–52.5 years). Most studies (5/6) reported body mass index or a combination of body height and body mass data, with all groups means fitting into the normal weight category (range of means for body mass index: 20.6–24.9). Most studies assessed passive muscles stiffness, with participants lying prone our supine on an examination table, except for Wolff et al. , who inv3.3.The studies we included were categorized as either high quality (3 studies) or moderate quality (3 studies). A notable omission across these studies was the calculation of sample size; only half of them (3 out of 6) furnished a comprehensive description. Detailed information can be found in 3.4.p = 0.03). The heterogeneity between the studies was moderate (I2 = 46%). However, the sensitivity analysis showed that the pooled effect was relatively robust, ranging from 0.25 to 0.49 (p = 0.003–0.040) when studies were removed one-by-one.Upper trapezius stiffness was assessed in 6 studies , with a p = 0.970), and the effects were very homogenous across the studies (I2 = 0%).Levator scapulae was assessed in three studies , 22, 42,p = 0.970). The heterogeneity between the studies was substantial (I2 = 77%).Sternocleidomastoideus was assessed in two studies , 42, witp = 0.940) and the two studies very homogenous (I2 = 0%). Finally, multifidus was assessed in two studies (p = 0.310) and the two studies were very homogenous (I2 = 0%).Splenius capitis was assessed in two studies , 36, wit studies , with a  studies . Again, 4.The meta-analysis revealed a slight elevation in trapezius muscle stiffness among CNP patients in comparison to those without symptoms. Stiffness levels of the levator scapulae, splenius capitis, SCM, and multifidus appeared comparable between CNP patients and controls. It it crucial to emphasize that this systematic review, based on case-control studies, does not clarify whether the enhanced trapezius stiffness is a result of, or a reason for, CNP. However, further research is encouraged to elucidate if addressing trapezius stiffness might be an integral objective in CNP rehabilitation strategies.r = 0.44; p = 0.003). However, there was no observed relationship between the stiffness of the right upper trapezius, bilateral pectoralis minor muscles, and the angles of the shoulder and neck. A limitation of this study was the undefined duration of symptoms. The second study (p = 0.008) and a modest correlation between trapezius stiffness and body mass index . Yet, this study lacked clarity on the symptom duration for the CNP group. Kocur et al.  was found between the CNP and control groups. However, these results are based on a very limited number of studies (2 studies for each muscle); therefore, further studies are needed to reach a more solid conclusion. Multifidus stiffness tended to be even lower in CNP patients, suggesting that this muscle may benefit from strengthening in this group. Along with the transversus abdominis, the multifidus is often considered critical for healthy spinal function , and strThis systematic review does come with certain limitations that merit attention. Firstly, our conclusions are drawn strictly from case-control studies, meaning we cannot infer direct cause-and-effect relationships. For clarity on whether muscle stiffness is a precursor or an outcome of CNP, future research should adopt a prospective approach. Even though the case-control studies we included were generally of commendable quality, they employed varied assessment techniques (spanning elastography to myotonometry) and had participants with differing durations of symptoms. Notably, three of these studies were solely focused on women, while others incorporated both genders without conducting gender-specific analyses. Assessment of muscle stiffness may be influenced by factors such as adipose tissue content , which c5.This article aimed to investigate which muscles exhibit increased stiffness in patients with CNP. Only a small increase in stiffness for the trapezius muscle was confirmed, whereas stiffness of the other muscles was similar in CNP patients and asymptomatic individuals. Nonetheless, a definitive link between muscle stiffness and CNP remains unestablished. As such, recommending a reduction in trapezius muscle stiffness as a primary rehabilitation strategy is still inconclusive and further research is needed.


Additionally, knowledge exerted both direct  and indirect effects  on practice. In conclusion, this study showed that the community GP team members had poor knowledge, favorable attitudes, and proactive practices. Education and training on the management of dysphagia complicated with aspiration pneumonia after stroke are urgently needed.This cross-sectional study investigated the knowledge, attitude and practice (KAP) of community general practice (GP) team members on dysphagia complicated with aspiration pneumonia after stroke in Shanghai between October 2022 and November 2022 using a self-administered questionnaire. A total of 551 questionnaires were collected  females), including 383 (69.51%) physicians. The mean KAP scores were 6.30 ± 1.54 (possible range: 0–12), 40.32 ± 5.11 (possible range: 9–45), and 72.54 ± 13.99 (possible range: 18–90), respectively. Multivariable linear regression analyses suggested that attitude , and holding research funding  were significantly associated with practice toward dysphagia complicated with aspiration pneumonia after stroke of community GP team members. The structural equation model (SEM) indicated that knowledge had a direct influence on attitude (β = 2.029,  Dysphagia is common after stroke and can result in aspiration pneumonia, poor nutrition, and dehydration ,2. AspirGeneral practitioners (GPs) are at the forefront of community care and are often the bridge to specialized care . After tThe knowledge, attitude, and practice (KAP) methodology is a quantitative approach that uses predefined questions formatted in standardized questionnaires and provides access to quantitative and qualitative information on a specific subject. The KAP model posits that enhanced knowledge fosters favorable attitudes, resulting in improved practices or behaviors and misconceptions or misunderstandings that may represent barriers to clinical activities ,23. In tTherefore, this study examined the KAP of community GP team members toward dysphagia complicated with aspiration pneumonia after stroke. The results could identify gaps that would require improvement through additional training.This cross-sectional study was conducted at Shanghai Community Health Service Center between 29 October 2022, and 22 November 2022, and enrolled physicians and nurses from GP teams. Physicians and nurses in training or internships were excluded. This study was approved by the Ethics Committee of Jinshan Hospital, Fudan University (No. JIEC 2022-S81). All participants signed the informed consent form before completing the survey.The questionnaire used in this study was based on the 2019 Updated Chinese Consensus Statement on Stroke-associated Pneumonia guidelines , ChineseTwo rounds of expert consultation were conducted to ensure the quality of the questionnaire. Five experts were selected, including two GP experts, a neurologist, and two nursing experts. After consultation, three new questions were added to the knowledge dimension based on the results of expert inquiries. K7: For individuals who have suffered a stroke, the preventive use of antimicrobial medications is a viable option. K11: To reduce the risk of stroke-associated pneumonia, it is advisable to minimize the use of medications, including glucocorticoids, proton pump inhibitors, and sedatives. K12: When treating aspiration pneumonia, it is essential that antimicrobial therapy encompasses anaerobic bacteria, Staphylococcus aureus, Gram-negative rods, aerobic bacteria, and fungi.The final questionnaire included (1) demographic data of the participants, including age, gender, level of education, type of occupation, length of service, professional title, research funding, and publications; (2) 12 questions about patients with dysphagia complicated by aspiration pneumonia after stroke ; (3) nine questions about the attitude of community GP team members towards patients with dysphagia complicated by aspiration pneumonia after stroke  to very negative (1 point), ranging from 9 to 45 points); and (4) 18 questions on the practice of the community GP team on patients with dysphagia complicated by aspiration pneumonia after stroke such as dysphagia screening, swallowing, rehabilitation training, aspiration prevention, and feeding pathways and other measures  to never (1 point), ranging from 18 to 90 points). In order to ensure the reliability of the questionnaire responses, a small pre-test was carried out, involving 52 copies. The pre-test results indicated high internal consistency, with a Cronbach’s α value of 0.950. A cutoff of 70% of the total score was used to determine good knowledge, favorable attitude, and proactive practice .https://www.wjx.cn (accessed on 29 October 2022)) to collect data through WeChat. The participants logged in by scanning the QR code and completing the questionnaire. In order to ensure quality and completeness, each IP address could only be used once to submit the questionnaire. All questions had to be answered. The research team members checked all questionnaires for completeness, internal coherence, and rationality.A convenience sampling approach was used to contact the directors of community health service centers and explain the importance of the survey. Once their participation was confirmed, a skilled research assistant offered a phone number or WeChat contact to stay in touch and provided relevant instructions to ensure that every valid questionnaire was accurately completed. The survey was delivered through an online platform. In order to ensure that only healthcare workers responded, the community directors personally distributed the survey to the community healthcare workers. The online questionnaire with a QR code was established using the Wen Juan Xing (WJX) platform (n = 39) and adding 10% to account for eventual invalid responses [The sample size was determined by multiplying 10 by the number of items in the questionnaire (esponses . Therefon (%) and analyzed using the chi-squared test. Pearson’s correlation was used to analyze the correlation between the knowledge, attitude, and practice scores. Univariable and multivariable linear regression analyses were used to analyze the factors influencing practice. Variables with p < 0.20 in the univariable analyses of the total practice score were included in the multivariable linear regression analyses. A two-sided p < 0.05 was considered statistically significant.STATA 17.0  was used for statistical analyses. Continuous data were expressed as means ± standard deviations (SD) and analyzed using ANOVA. Categorical data were expressed as p = 0.041), different professional titles (p = 0.013), and with and without publications (p = 0.026), in attitude between different levels of education (p < 0.001), and in practice between GP team members with and without research funding (p = 0.031)  females), including 383 (69.51%) physicians. The mean KAP scores were 6.30 ± 1.54 (possible range: 0–12), 40.32 ± 5.11 (possible range: 9–45), and 72.54 ± 13.99 (possible range: 18–90), respectively. There were significant differences in knowledge between different lengths of service ( funding . There w= 0.031) .Among the knowledge dimensions, “Dysphagia is one of the most common clinical complications after stroke, greatly increasing the risk of death and poor prognosis. (K1)” had the highest correct rate, while “Anti-infective therapy should be initiated within 4 h in all patients with suspected or confirmed stroke-associated pneumonia if patients were complicated by sepsis or septic shock.  (K6)” had the lowest correct rate .Pearson’s correlation analyses showed that the knowledge scores were correlated to the attitude scores and practice scores “Swallowing screening and rehabilitation training” item scores, “Aspirations prevent and feeding pathway” item scores, and “Other measures” item scores. The attitude scores correlated with the practice scores “Swallowing screening and rehabilitation training” item scores, “Aspirations prevent and feeding pathway” item scores, and “Other measures” item scores. The practice scores correlated with the “Swallowing screening and rehabilitation training” item scores, “Aspirations prevent and feeding pathway” item scores, and “Other measures” item scores .The multivariable linear regression analyses suggested that attitude  and holding research funding  were significantly associated with practice toward dysphagia complicated with aspiration pneumonia after stroke of community GP team members .Multivariable linear regression analyses showed that attitude , nurses , length of service above 20 years , holding research funding , and having publications  were significantly associated with the practice of “Swallowing screening and rehabilitation training”. Attitude  and holding research funding  were significantly associated with the practice of “Aspiration prevention and feeding pathway”. Additionally, attitude , professional title of associate senior/senior , and holding research funding  were significantly associated with the practice of “Other measures ” .p < 0.001) and attitude had a direct impact on practice . Additionally, knowledge exerted both direct  and indirect effects  on practice  indicated that knowledge had a direct influence on attitude  and it may not be generalized to other areas or subjects ,23. SecoThe results showed that the knowledge about dysphagia complicated with aspiration pneumonia after stroke of community GP team members was positively correlated with their attitude and practice toward dysphagia complicated with aspiration pneumonia after stroke. In addition, knowledge and attitude were positively correlated with their practice, while holding research funding was negatively associated with their practice. The findings of this study may help the development of educational interventions to improve the management of dysphagia after stroke and reduce the risk of aspiration pneumonia.


Spain has an aging population; 19.93% of the Spanish population is over 65. Aging is accompanied by several health issues, including mental health disorders and changes in the gut microbiota. The gut-brain axis is a bidirectional network linking the central nervous system with gastrointestinal tract functions, and therefore, the gut microbiota can influence an individual’s mental health. Furthermore, aging-related physiological changes affect the gut microbiota, with differences in taxa and their associated metabolic functions between younger and older people. Here, we took a case–control approach to study the interplay between gut microbiota and mental health of elderly people. Fecal and saliva samples from 101 healthy volunteers over 65 were collected, of which 28 (EE|MH group) reported using antidepressants or medication for anxiety or insomnia at the time of sampling. The rest of the volunteers (EE|NOMH group) were the control group. 16S rRNA gene sequencing and metagenomic sequencing were applied to determine the differences between intestinal and oral microbiota. Significant differences in genera were found, specifically eight in the gut microbiota, and five in the oral microbiota. Functional analysis of fecal samples showed differences in five orthologous genes related to tryptophan metabolism, the precursor of serotonin and melatonin, and in six categories related to serine metabolism, a precursor of tryptophan. Moreover, we found 29 metabolic pathways with significant inter-group differences, including pathways regulating longevity, the dopaminergic synapse, the serotoninergic synapse, and two amino acids. In 2000, according to data from INE, the Spanish national statistics office 1, the poAccording to the World Health Organization, over 20% of adults aged 60 and over suffer from a mental or neurological disorder. Mental disorders are defined as “health conditions characterized by alterations in thinking, mood, or behavior (or a combination thereof) associated with distress and impaired functioning.” Mental health disorders affect mood, thinking, and behavior. These also include depression, anxiety, insomnia, eating disorders, and addictive behaviors. In the Comunidad Valenciana (Spain), there is a 24.6% risk of mental health disorders in adulthood, which can rise to 50% in people over 84 years old . GeriatrThe elderly may experience life stressors common to all people, but also other stressors that are more common in later life, like a significant ongoing loss in capacities and a decline in functional ability. For example, older adults may experience reduced mobility, chronic pain, frailty, or other health problems, for which they require some form of long-term care . In addiThere is growing evidence that the gut-brain axis, a bidirectional communication network that links the emotional and cognitive centers of the brain with peripheral intestinal functions, plays a role in promoting mental health or disorders . It reguThe transmission of sensory information from the gut to the brain is mediated by hormonal and neural circuits . After aIt is also interesting to mention the functional role of essential amino acids produced by gut microbes, in particular tryptophan. The majority of tryptophan in the human body circulates in the blood attached to albumin, while only 10–20% can be found circulating freely . StudiesLow serotonin levels in the CNS contribute to significantly increased depression and anxiety . The 5-HThe biosynthesis of 5-HT is entirely dependent on the enzyme tryptophan hydroxylase (TPH), which converts tryptophan into 5-hydroxytryptophan (5-HTP) . TPH is More than 90% of tryptophan is metabolized through the kynurenine pathway (KP). Indolamine 2, 3-dioxygenase (IDO), expressed in various organs such as the brain, the GI tract, and the liver, and tryptophan 2, 3-dioxygenase (TDO), mainly expressed in the liver, are the enzymes that catalyze the first step of tryptophan metabolism on KP . These eOral health is also influenced by aging, with an increased prevalence of periodontal disease . There aIn the present study, we carried out 16S rRNA gene and metagenomic sequencing to determine differences in the taxa, functions, and metabolic pathways of intestinal and oral microbiota in a cohort of over 65-year-olds in the Comunidad Valenciana (Spain). The study included individuals treated with medication for anxiety, depression, and/or insomnia and those who were not diagnosed with any mental health disorders.2.2.1.A case–control study was performed. Fecal and saliva samples from 101 volunteers over 65 were collected (EE cohort). All participants were residents of the Comunidad Valenciana (Spain) and filled out a questionnaire about their diet, general health, habits, weight and height (with which the body mass index (BMI) has been calculated), employment situation, medical history, and vaccinations. Some of this information is collected in 2.2.Fecal samples were collected from each volunteer in sterile tubes, containing 10 mL of RNAlater Solution (Ambion) to stabilize and preserve the integrity of nucleic acids prior analysis. Samples were homogenized by adding 10 mL phosphate-buffered saline (PBS)  and then centrifuged to eliminate solid waste. The obtained fecal microbial suspension was aliquoted and stored at −80°C until further processing. With respect to saliva samples, 3 mL was collected from each volunteer in sterile containers, aliquoted, and stored at −80°C until further processing.2.3.A total of 500 μL of fecal suspension was pelleted and weighted and the total genomic DNA was extracted using the QIAamp DNA mini stool kit (Qiagen). The fecal suspension pellet was resuspended in 1 mL of inhibitEX Buffer from the extraction kit and then 20 μL of lysozyme (10 mg/mL) was added for cellular lysis, followed by 30 min incubation at 37°C. The lysate was subjected to mechanical treatment with 200 μL of 150–212 μm diameter Glass Beads (Sigma) and heated to 95°C for 5 min. The samples were then centrifuged and 600 μL of the supernatant was treated with 45 μL of proteinase K. The following steps were carried out according to the manufacturers’ recommendations.2.4.A total of 250 μL of saliva was pelleted at 4°C, weighted, and total genomic DNA was extracted using the QIAamp DNA mini kit (Qiagen) with a few preliminary steps. The pellet was resuspended in the leftover supernatant and incubated for 45 s in a 37°C ultrasonic cleaner (Raypa). Then, 130 μL of AL Buffer from the extraction kit was added to each sample and then 10 μL of “enzyme mix” containing 2.5 μL of lysozyme (100 mg/mL), 2.5 μL of lysostaphin (5 mg/mL), 2.5 μL of mutanolysin, and 2.5 μL of nuclease-free water was also added and incubated for one-hour at 37°C. Subsequently, 20 μL of proteinase K from the extraction kit was added to the lysate and the samples were incubated for 10 min at 56°C, followed by 10 min at 70°C, and 3 min at 95°C incubation. The lysate was then mixed with 200 μL of 100% ethanol and placed on the kit mini-column. Finally, the washing steps were performed according to the manufacturers’ recommendations.2.5.For fecal and saliva samples, V3-V4 hypervariable regions of the 16S rRNA gene were amplified by PCR using primers: 5′-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGCCTACGGGNGGCWGCAG-3′ (forward); and 5′-GTCTCGTGGGCTCGGAGATG TGTATAAGAGACAGGACTACHVGGTATCTAATCC-3′ (reverse). Amplicons were purified using NucleoMag NGS Clean-up and Size Select magnetic beads (Macherey-Nagel) and then Illumina sequencing adapters using the Nextera XT Index Kit (Illumina) were attached. Quantification of DNA was performed with a Qubit 3.0 fluorometer using the Qubit dsDNA HS assay kit (Thermo Fisher Scientific). Amplicon libraries were pooled in equimolar ratios for sequencing on a MiSeq platform of Illumina (2 × 300 bp paired-end reads) following the manufacturers’ recommendations.2.6.For fecal samples, whole-genome sequencing was also performed from total DNA. Metagenome libraries were obtained with Illumina’s Nextera XT DNA Library Preparation Kit. Short fragments were eliminated using NucleoMag NGS Clean-up and Size Select magnetic beads (Macherey-Nagel) and the obtained purified libraries were sequenced in a MiSeq platform of Illumina (2 × 150 bp paired-end reads) following the manufacturers’ recommendations.2.7.In-house bioinformatic analysis pipelines were applied. For 16S rDNA gene analysis, we obtained the amplicon sequence variant (ASV) data with the DADA2 pipeline , which rFor metagenomic analysis, once the raw sequencing data were obtained, the sequencing adaptors were removed by Cutadapt software. Low-quality reads were eliminated using PRINSEQ, as well as short reads, and reads with a high percentage of ambiguous bases, in addition to low entropy reads. To join overlapping pairs to obtain longer sequences, the FLASH software was used. Non-overlapping forward pairs were also taken into account while non-overlapping reverse pairs were discarded. The host (human) genome and the non-coding ribosomal RNA sequences were filtered out using Bowtie2 with the SILVA database. The reads were then assembled into contigs using Megahit and mapped against the contigs using Blast. Open reading frames (ORF) were predicted using the Prodigal software and abundance tables were created. Functional annotation was performed by mapping each ORF against protein family database using the program HMMER and the KEGG Orthology database. Finally, Kaiju was used for taxonomical annotation of metagenome data. Once the functional compositional matrix was obtained, the results were grouped into functional categories and metabolic pathways.Each matrix, including the ASV, phylum, genus, and functional compositional matrices were then analyzed. The R statistics software was applied to obtain alpha (Shannon and Chao1 indexes) and beta diversity , Permanova test, and Wilcoxon non-parametric test). Correlation analysis between the saliva and fecal samples was obtained using the sPCA mixomics approach for a single omic .2.8.Functional capacities of microbiomes are dependent on the taxonomic structure of the microbial community, because each taxon is associated to putatively different functions and abundances. The functional metagenome could be inferred considering the taxonomic composition of the microbial community. Changes in the composition and/or abundance of one or more taxa can cause changes in functional capacities. This has recently been described as taxa-function relationships .Two main systemic parameters can be estimated to determine the functional robustness of microbial communities: attenuation and buffering. The determination was done using the microbial community taxa-function robustness estimation pipeline developed by We have implemented some modifications in the original pipeline in order to improve sensitivity and accuracy. First, we used PICRUSt2  to deriv2.9.The curated sequences from 16S rRNA gene and metagenomes were deposited in the EBI Short Read Archive under the study accession number PRJEB56919, with accession numbers ERS13596619- ERS13596719 and ERS13596821-ERS13596921 for the16S rRNA gene from fecal and saliva samples, respectively, and ERS13596720-ERS13596820 for metagenomes.3.3.1.We obtained samples from a cohort of 101 volunteers over 65 years old (EE cohort) from the Comunidad Valenciana (Spain), 28 of whom were treated with medication for anxiety, depression, and/or insomnia (EE|NOMH group) and 73 not treated for any mental health disorders (EE|NOMH group). The medication of the EE|MH group included modulators of GABA receptors, modulators of serotonin availability, or sleep regulators . Some pa3.2.A total 7,050,645 reads were sequenced from fecal samples, 18.23% of which were removed after quality check and host filtering, obtaining an average of 57,086 reads per sample . Taxonomic annotation showed two phyla with main representation in the EE cohort: Firmicutes (48.92%) and Bacteroidota (40.76%). Other phyla with lower representation included: Proteobacteria (4.25%), Actinobacteriota (2.82%), Verrucomicrobiota (1.31%), Desulfobacterota (0.70%), Cyanobacteria (0.15%), and Synergistota (0.12%).p = 0.003 and 0.038, respectively; ps of 0.04, 0.021, and 0.002, respectively. The Wilcoxon non-parametric test also showed statistically significant differences  between the two groups in the following eight genera  . Taxonomic annotation showed that the most represented phyla were Firmicutes (30.22%), Bacteroidota (28.91%), and Proteobacteria (20.48%), and other phyla with lower representation that included Fusobacteriota (8.15%), Actinobacteriota (5.82%), Patescibacteria (2.97%), Campilobacterota (2.21%), and Spirochaetota (0.83%). Similar results to those obtained with fecal samples were detected for the alpha diversity at the genus and ASV levels of saliva samples. Shannon and Chao indexes were not significantly different with  EE|NOMH ,B. Howev = 0.02) . We iden = 0.02) : Veillonfive ASV , which c3.4.Lachnospira (gut) with the genera Megasphaera and Atopobium  and the genus Subdoligranulum (gut) with the genus Lachnoanaerobaculum  showed significant negative correlations, while the genus Odoribacter (gut) with the genera Alloprevotella and Haemophilus  and the genera Lachnoclostridium, and Colidextribacter (gut) with the genus Megasphaera  showed positive correlation (Alistipes (gut) had significant negative correlation with the genera Veillonella and Prevotella  in the EE|NOMH group ; of these 270,608,848 were correctly assigned to KEGG Orthology (KO) categories .p = 0.24; p < 0.05). It is worth mentioning that five are involved in tryptophan metabolism   see  and six 667) see , which w667) see . Further667) see . FinallyMH group .3.6.p − value = 0.25; see p = 0.02; p = 0.0084) and phenylalanine metabolism  and serotoninergic synapse  or buffering  in fecal samples. Attenuation and buffering for each individual are shown in p value = 0.41) and buffering  were not significant between groups. Moreover, values of attenuation and buffering for each individual within each group  while in saliva samples, we found differences in attenuation for four superpathways . In case of buffering, no differences were found in fecal samples  in mouse models. Anhedonia is one of the two core symptoms of depression  gene expression  and tumor necrosis factor-alpha (TNF-α) among other pro-inflammatory cytokines, and its activation is correlated with the intensity of depressive symptoms . Flavonifractor has previously been reported as higher in individuals with major depressive disorder  are the enzymes that catalyze the first step of tryptophan metabolism in this pathway . On the symptoms . IDO actdisorder , generaldisorder , affectidisorder , and bipdisorder . Flavonie scores . Parker pression . This gepression .Bacteroides were also significantly higher in the EE/MH mental-health treatment group. The role of Bacteroides in mental health is highly controversial, with some authors observing the genus to be lower in patients suffering from mental health disorders  was markedly higher in the EE|MH group. This enzyme carries out the first step in the indolic pathway, transforming tryptophan into indole . Indole id cells . They arnd mouse .GABA is the principal inhibitory neurotransmitter in the brain. It affects the control of homeostasis during stress and has been associated with mental health disorders such as anxiety and depression . GABA anOscillibacter, which we found to be enriched in the EE|MH group, has valeric acid as its main metabolic product; this metabolite mimics GABA. Valeric acid can bind with the GABAa receptor, which explains the association between valeric acid-producing bacteria and depression . For the remaining superpathways not directly related with metabolism the differences observed could induce variations in cell division and growth of prokaryotic cells, without obvious consequences in community taxonomic composition dynamics, which could finally modify the values of those parameters of robustness.Therefore, at least in oral microbiota, in-depth studies should address the relationship between changes induced in functional capacity by alteration or disturbances of the microbial community, and the medication to treat pathologies. In this respect, there are numerous references on the role of medication in Xerostomia related with salivary gland dysfunction, and oral diseases associated to diazepine  and otheSpain has an aging population, with 19.93% of the whole population over 65 years of age, in 2021. This age range corresponds to a higher risk of suffering mental health issues, reaching around 25% in 65-year-olds and up to 55% in 85-year-olds . It is ihttps://www.ebi.ac.uk/ena), accession number PRJEB56919.The datasets presented in this study are deposited in the European Nucleotide Archive repository  of Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO). All the volunteers provided written informed consent before their participation. The patients/participants provided their written informed consent to participate in this study.NP and AB carried out the experiments and processed sequencing data. BP-R developed the robustness analysis. AA performed the bioinformatic analyses. SR-R and AM designed the experiments and wrote the manuscript. All authors contributed to the article and approved the submitted version.This research was funded by the Spanish Ministry of Science and Innovation (PID2019-105969GB-I00) and supported by a grant  from the Generalitat Valenciana.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


There is an urgent need to identify differentiating and disease-monitoring biomarkers of schizophrenia, bipolar disorders (BD), and major depressive disorders (MDD) to improve treatment and management.α-Melanocyte Stimulating Hormone (α-MSH), β-endorphin, neurotensin, orexin-A, oxytocin, and substance P were investigated using quantitative multiplex assay method. Psychotic symptoms were measured using the Brief Psychiatric Rating Scale (BPRS) and Positive and Negative Syndrome Scale (PANSS), manic symptoms using the Young Mania Rating Scale (YMRS), and depressive symptoms using 17 item-Hamilton Depression Rating Scale (HAMD). We additionally measured cognitive function by using a battery of tests given to all participants.We recruited 54 first-episode schizophrenia (FES) patients, 52 BD patients, 35 MDD patients, and 54 healthy controls from inpatient and outpatient clinics. α-MSH, neurotensin, orexin-A, oxytocin, and substance P were decreased in the three patient groups compared with controls. Neurotensin outperformed all biomarkers in differentiating patient groups from controls. There were no significant differences for 6 neuropeptides in their ability to differentiate between the three patient groups. Higher neurotensin was associated with better executive function across the entire sample. Lower oxytocin and higher substance p were associated with more psychotic symptoms in FES and BD groups. β-endorphin was associated with early morning wakening symptom in all three patient groups.Our research shows decreased circulating neuropeptides have the potential to differentiate severe mental illnesses from controls. These neuropeptides are promising treatment targets for improving clinical symptoms and cognitive function in FES, BD, and MDD. Schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorders (MDD) are common and serious mental illnesses associated with substantial morbidity and mortality as well as high personal and societal costs . Althougvia one or more of a correspondingly large number of 7-transmembrane, G protein-coupled receptors (GPCRs) (>200) , are all implicated in mental illness  (>200) . Neurope) (>200) . Previou illness , 20–22.  illness , and NT  illness . Plasma  illness . Animal  illness , 26. β-eeceptors . It is ieceptors , 28.Despite these findings, neuropeptide studies still offer little insight into either core pathophysiology or treatment options for SCZ, BD, and MDD . PreciseFES, BD, MDD, and healthy control (HC) volunteers were recruited for the current study from in- and outpatient psychiatric facilities at West China Hospital of Sichuan University. We recruited 54 FES , 52 BD , and 35 MDD , diagnosed according to standard operational criteria in the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV). Fifty-four healthy volunteers  were included. Healthy volunteers were screened for major psychiatric disorders using the Structured Clinical Interview for DSM-IV, non-patient edition. We used the Positive and Negative Symptom Rating Scale (PANSS), the Brief Psychiatric Rating Scale (BPRS), the Young Mania Rating Scale (YMRS), and 17-item Hamilton Depression Rating Scale (HAMD) to measure the symptom severity. The clinical rating scales are evaluated by experienced psychiatrists within 3 days after the patients are recruited in the study. Patients were excluded if they met the criteria for alcohol or substance abuse within 1 year of screening, and significant medical illness. All right-handed subjects provided written informed consent. The study was approved by the West China Hospital of Sichuan University Ethics committee, and the first subject was included in March 5th, 2015.Intelligence quotient (IQ), verbal IQ, and performance IQ scores of all participants were assessed using the seven-subtest short form of the revised Wechsler Adult Intelligence Scale in Chinese . The Camg for 10 min, and the separated plasma was immediately divided into 0.5-mL aliquots and stored at −80°C. Plasma factors were evaluated using MILLIPLEX® MAP kits . The MILLIPLEX® MAP Human Neuropeptide Magnetic Bead Panel is used for the simultaneous quantification of the following 6 analytes in any combination: α-MSH, β-Endorphin, Neurotensin, Orexin-A, Oxytocin, and Substance P. This kit may be used for the analysis of all or any combination of the above analytes in tissue/cell lysate, culture supernatant samples, and CSF, serum or plasma samples. The immunoassay procedure was followed by the manufacture’s standard procedure and was described by our group elsewhere . Fisher’s exact test was used to check the statistical significance of between-group differences. Spearman or Pearson correlation was conducted to test the correlation coefficient for categorical variables or continuous variables, respectively. The differences in cognitive function and the plasma neuropeptides among groups were tested by ANCOVA, with age, gender and BMI as covariates, the education year was additionally co-variated out for cognitive function analysis. The post-hoc group comparison was conducted with the alpha value set to 0.05 and with Bonferroni correction, which was a relatively strict method used to correct for multiple comparisons. The results are presented as mean ± standard deviation unless otherwise specified .Stata 14.0 and SPSS 24.0 were used for the analysis. The distribution of the continuous variables was checked using Shapiro–Wilk’s test. Logpecified . Differepecified . Differe10 α-MSH, log10 β-endorphins, log10 neurotensin, log10 orexin A, log10 oxytocin, and log10 substance P as independent variables. The least significant variables were removed one at a time until only significant variables remained. Significance was taken as p < 0.05. Finally, separate stepwise linear regression analyses were used to test associations between plasma neuropeptides and clinical symptom scores or cognitive function. The linear regression model used age, gender, education, BMI, group status, logDemographic, clinical, plasma biomarkers, and cognitive features of patients and healthy controls are presented in Post hoc analyses revealed decreased total IQ scores, and performance IQ scores in the FES patient group compared to controls. There were no significant differences in SOC-MM5M scores between the patients and control groups . The adjusted multivariate coefficient of determination (R2) for the model was 0.05 for the predictor. The standardized β coefficient value for neurotensin was −0.22, with a t value of −2.83 , N2 , N3 , and G9  as independent variables, we found that the regression models were all significant because all p-values were all lower than 0.05. Oxytocin was the only variable that could predict PANSS subscale symptom scores, with lower oxytocin levels predicting higher PANNS scores. When using the BPRS deficiency energy factor score as the dependent variable, we found that oxytocin level explained a significant amount of the variance in the BPRS deficiency energy factor score in Step 1 . In the second step, the inclusion of substance P (β = 4.33) enhanced the relationship between BPRS deficiency energy factor score and oxytocin level (β = −0.65) based on the magnitude of the standardized beta-coefficient in Step 2 . The adjusted multivariate coefficient of determination (R2) for the final model was 0.099 for the predictors. The standardized β coefficient value for oxytocin and substance P were − 0.65 and 4.33, with t values of −3.04 and 2.02 in step 2 . The inclusion of log10 endorphin (β = −0.25) enhanced the relationship between early morning awakening severity and MDD group status (β = 0.56) based on the magnitude of the standardized beta-coefficient in Step 2 . The adjusted multivariate coefficient of determination (R2) in step 2 was 0.36 for the predictors. The standardized β coefficient value for MDD group status and log10 endorphin were 0.56 and −0.25, with t values of 6.90 and −3.12 , in the three patient groups is presented in 3.12 see .r = 0.41, p < 0.01) . Furthermore, we have demonstrated that the plasma neuropeptides were differentially associated with specific clinical symptoms and executive function across disease groups. Our results indicate the disease monitoring and disease-categorizing potential of plasma neuropeptides, which could therefore be used in clinical and research settings  study reported that after ECT treatment, the patient group had significantly increased endorphin levels . Loss of orexin neurons and decrease of orexin levels in plasma are observed in patients with depression, schizophrenia, and other neurodegenerative diseases (α-MSH is one cleavage product of the pituitary hormone pro-opiomelanocortin (POMC), and numerous studies have described the role of POMC in metabolic syndrome , National Natural Science Foundation of China , Special Foundation for Brain Research from Science and Technology Program of Guangdong (2018B030334001 to TL), 2021 Project for Hangzhou Medical Disciplines of Excellence and Key Project for Hangzhou Medical Disciplines, 1.3.5 Project for Disciplines of Excellence at West China Hospital of Sichuan University , and Introductory Project of the Suzhou Clinical Expert Team (SZYJTD201715 to XD and TL).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Anterior resection (AR) is considered the gold standard for curative cancer treatment in the middle and upper rectum. The goal of the sphincter-preserving procedure, such as AR, is vulnerable to anastomotic leak (AL) complications. Defunctioning stoma (DS) became the protective measure against AL. Often a defunctioning loop-ileostomy is used, which is associated with substantial morbidity. However, not much is known if the routine use of DS reduces the overall incidence of AL.Elective patients subjected to AR in 2007–2009 and 2016-18 were recruited from the Swedish colorectal cancer registry (SCRCR). Patient characteristics, including DS status and occurrence of AL, were analyzed. In addition, independent risk factors for AL were investigated by multivariable regression.2, and neoadjuvant therapy were independent risk factors for AL.The statistical increase of DS from 71.6% in 2007–2009 to 76.7% in 2016–2018 did not impact the incidence of AL (9.2% and 8.2%), respectively. DLI was constructed in more than 35% of high-located tumors ≥ 11 cm from the anal verge. Multivariable analysis showed that male gender, ASA 3–4, BMI > 30 kg/mRoutine DS did not decrease overall AL after AR. A selective decision algorithm for DS construction is needed to protect from AL and mitigate DS morbidities.The online version contains supplementary material available at 10.1186/s12893-023-01998-5. Anterior resection (AR) is considered the gold standard for the curative treatment of cancer in the middle and upper rectum . The widDLI becomes permanent in about 25% of the cases. The local and systemic physiological changes due to DLI can vary from minor symptoms of skin irritation and leakage (59%) to significant issues like dehydration, obstruction, and parastomal hernia (25%) . One-thiThis study aimed to evaluate whether the frequency of AL has decreased as the usage of DLI has increased and, as a secondary outcome, investigate risk factors for AL. We hypothesized that the lack of clear indications for DLI leads to increased DLI usage without reducing AL.This study is a population-based retrospective cohort study of patients subjected to rectal cancer surgery in Sweden. The SCRCR is a nationwide registry including rectal cancer patients since 1995 in Sweden with high validity and coverage . We encoRectal cancer was defined as adenocarcinoma within ≤ 15 cm from the anal verge measured with rigid sigmoidoscopy.According to the International Study Group of Rectal Cancer (ISREC), AL after AR for rectal cancer is defined as a communication between the two cavities  manifested as a defect in the anastomosis (anastomotic staple or suture line), the presence of a presacral pelvic abscess or a rectovaginal fistula  and diviDLI is an ileostomy that diverts bowel contents and protects the newly reconstructed colorectal anastomosis applied during the elective AR.The partial mesorectal excision (PME) variable will be registered in 2022 after the study is completed and the colorectal anastomosis level is not enlisted in SCRCR. Tumor height from the anal verge is employed as a proxy for PME, with PME operations defined as tumors located 11 cm or higher from the anal verge.Ethical approval was obtained via the Swedish Ethical Review Authority (Diary number 2020 − 01082).Statistical analyses were made using IBM SPSS version 26. Demographic characteristics were reported as medians with first and third interquartile range (IQR) when continuous and categorical variables as numbers and percentages. Mann-Whitney U test was applied for continuous variables, Fisher’s Exact or Chi-square tests for categorical variables. A two-sided p-value < 0.05 was considered statistically significant. Missing data were reported when exceeding 2% in a variable.Risk factors for AL were identified using a binary logistic regression model for a univariable and multivariable analysis, including significant univariable variables and other clinically essential indicators like DLI, and index operation date .A total of 3948 AR procedures for rectal cancer were performed during 2007 to 2009 and 2016 to 2018. One hundred thirty-one patients were non-radically resected, 123 patients had missing data regarding resection margins, and six with unregistered DLI status were excluded resulting in 3688 included patients in the study cohort, Fig. DLI patient characteristics and demographics are displayed in Table Compared to the former cohort, patients in the latter group comprised more patients with ASA 3–4 , BMI > 30 , and had a longer hospital stay . Throughout the research period, the neoadjuvant therapy was either a short course of 5 × 5 Gy or radio-chemotherapy 2 × 25 Gy with radiosensitizing capecitabine, with the latter group receiving less neoadjuvant therapy . Moreover, fewer patients in the latter group were treated with adjuvant therapy . Perioperatively, the latter cohort more frequently underwent minimally invasive anterior resection and high ligation of the inferior mesenteric artery. The characteristics of the PME and TME groups are shown in Supplement Tables Although more than two-thirds of the patients, 71.6% (1345/1879), were diverted by DLI 2007–2009), the diversion rate increased further to 76.7% (1387/1809) (p < 0.001) in the latter group (2016–2018), shown in Table 007–2009,There was no significant reduction in AL incidence over 11 years despite the expansion in DLI usage (9.2% (124/1879) in 2007–2009 compared to 8.2% (114/1809) in 2016–2018) (p = 0.35). The number of reoperations for AL was unchanged (4% (58/1345) vs. 3% (46/1387), respectively). Comparisons between +/-DLI in the subgroups TME and PME are shown in supplement Tables The study cohort was divided into +/-AL, and AL risk factors were analyzed Table . PatientMale gender, ASA class 3–4, BMI 30 or above, and neoadjuvant therapy remained risk factors for AL in the multivariable analysis  was registered from 2007 to 2009, although RECTODES-trial was not reported until 2007 [AL is deemed one of the most feared surgical complications after sphincter-preserving surgery. Significant efforts to preclude its occurrence are conducted by minimizing modifiable risk factors and implementing protective measures, including DS. There are inconsistent results on how DS affects AL rates despite well-conducted randomized controlled trials, prospective multicentre studies, and meta-analyses , 23. TheAdditionally, a Swedish regional study found an increase in DS construction from 15% (2002–2006) to 91% (2007–2011), while AL lingered around 10% . The conThe interpretation of the results from RCTs advocating the protective role of DS must consider the circumstances that entail DS construction. In the case of the RECTODEStrial, several detrimental factors were considered. More than two-thirds of AR patients were not accepted for randomization. In our opinion, the most critical exclusion criterion was anastomosis level > 7 cm above the anal verge or resection with a PME procedure. However, in Sweden, a high proportion 25%) of AR patients have high-located tumors , and about 34% subjected to PME were diverted with DLI in Sweden , 25. Thi% of AR pFurthermore, the most frequent exclusion factor was intraoperative technical difficulties or intraoperative adverse events, which would create a selection bias and, consequently, decrease the external validity.Blok RD et al. suggested a shift from routine to a highly selective defunctioning ileostomy (HS-DI) after laparoscopic and transanal TME. With a diversion rate of 8% compared to 90% in a historical group, the incidence of AL at 30 days and one year was similar in both groups . RecentlThe short- and long-term stoma-related morbidities for a DS are not negligible. The few weeks after hospital discharge carry a high risk of readmission (17%) due to dehydration by high-output stoma . MoreoveThis observational study is strengthened by a large sample representing the national population of this patient group and thus enhances its generalizability and external validity. It was unbiased in selecting all consecutive patients from two periods. However, this registry-based study is limited by unavailable variables. The possibility to explore the effect of DLI on attenuating AL severity and delaying its presentation is hampered by the lack in SCRCR of details on AL presentation and management such as diagnosis date, type of treatment , details on reoperation, stoma reversal, PME definition and missing data on adjuvant therapy. Another limitation is the unavailability of neoadjuvant treatment toxicity. Neoadjuvant toxicity could be studied for its potential effect on anastomotic healing.This population-based study demonstrates an inefficient DLI role in diminishing the risk of AL in routine AR use. Other preventive measures are being studied, including ghost ileostomies, HS-DI, an AL-check list, and scheduled postoperative AL surveillance, including sigmoidoscopy, labs, and rectography. Thereby, an urge for a decision algorithm regarding selective criteria for DLI is called for to spare DLI usage in this complex patient group with multiple risk factors for AL. Noteworthy, there is a significant shift from open to laparoscopic approach in TME-procedure. Therefore, new studies should explore the protective role of DLI specifically in the current surgical practice of laparoscopic and trans-anal TME procedures.Below is the link to the electronic supplementary material.Supplementary Material 1