Rationale: To test whether novel biomarkers, such as microribonucleic acids (miRNAs), and nonstandard predictive models, such as decision tree learning, provide useful information for medical decision-making in patients on hemodialysis (HD).Methods: Samples from patients with end-stage renal disease receiving HD included in the AURORA trial were investigated (n=810). The study included two independent phases: phase I  and phase II . The composite endpoint was cardiovascular death, nonfatal myocardial infarction or nonfatal stroke. miRNA quantification was performed using miRNA sequencing and RT-qPCR. The CART algorithm was used to construct regression tree models. A bagging-based procedure was used for validation.Results: In phase I, miRNA sequencing in a subset of samples (n=20) revealed miR-632 as a candidate (fold change=2.9). miR-632 was associated with the endpoint, even after adjusting for confounding factors (HR from 1.43 to 1.53). These findings were not reproduced in phase II. Regression tree models identified eight patient subgroups with specific risk patterns. miR-186-5p and miR-632 entered the tree by redefining two risk groups: patients older than 64 years and with hsCRP<0.827 mg/L and diabetic patients younger than 64 years. miRNAs improved the discrimination accuracy at the beginning of the follow-up (24 months) compared to the models without miRNAs (integrated AUC [iAUC]=0.71).Conclusions: The circulating miRNA profile complements conventional risk factors to identify specific cardiovascular risk patterns among patients receiving maintenance HD. Cardiovascular disease (CVD) represents a major cause of morbidity and mortality among patients receiving maintenance hemodialysis (HD) Circulating microribonucleic acids (miRNAs) have emerged as a powerful approach to assist in medical decision-making Using classification tree models based on the so-called chi-squared automatic interaction detector (CHAID) algorithm, we have recently proposed the use of circulating miRNAs to identify specific subpopulation of patients in the context of coronary heart disease (CHD) This study sought to assess whether plasma miRNAs could improve cardiovascular risk prediction in patients with end-stage renal disease receiving HD. To do so, we used two different strategies: 1) the traditional biomarker evaluation considering a direct linear relationship with limited interactions between predictors; and 2) taking into account high-level interactions and more complex relationships among the biomarkers, and among biomarkers and the outcome, through regression tree models.Study design, patient baseline data and outcomes of the trial A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events (AURORA) have been previously described Since the cardiovascular event rate was similar in both treatment arms The composite endpoint was time to major cardiovascular event (MACE) defined as death from cardiovascular causes, non-fatal myocardial infarction or non-fatal stroke. A sudden, unexpected death was attributed to CHD, definite or suspected, if there was inadequate information to ascribe a non-cardiovascular cause. All events were adjudicated by an independent endpoint committee blinded to treatment allocation.Figure .The study is composed of two clearly defined phases Supplemental Table S1.Among the 2776 patients included in the AURORA trial, 205 patients with endpoint (cases) were matched with 205 patients without endpoint (controls) on age, sex, region, body mass index (BMI), KT/V  and the AURORA Risk Score that includes age, albumin, hsCRP, history of CVD and history of diabetes Supplemental , respectively.Among the population of unmatched patients with blood sample available (n=1731), 200 cases and 200 controls were randomly drawn. One low-quality sample was excluded. The study population in phase II was composed of 399 patients . Characteristics of phase II study population and comparison of matching variables and miRNA levels between the two populations (phase I and phase II) are displayed in Different methodological approaches were used for miRNA screening and validation and are described as follows.The HTG EdgeSeq miRNA Whole Transcriptome Assay (miRNA WTA)  was applied to detect miRNAs differentially expressed in plasma samples from 10 cases and 10 matched controls. The HTG EdgeSeq system combines HTG's proprietary quantitative nuclease protection assay (qNPA) chemistry with a new generation sequencing (NGS) platform to enable the semiquantitative analysis of a panel of targeted genes in a single assay. The assay contained 2102 probes, including 2083 miRNAs, 13 housekeeper genes, five negative process controls and one positive process control. Sequencing was performed on the Illumina MiSeq platform. All procedural steps were performed in the appropriate physical locations in accordance with HTG OP No. 0028, Controlled Lab Areas. All samples were prepared in accordance with OP No. 0036, HTG EdgeSeq Sample Preparation.8 copies/µl) (Qiagen) was added to each sample immediately before starting the isolation procedure as a quality control measure of the RNA isolation. RNA was eluted from the columns using 15 µL of water, and 2.5 µL of diluted RNA was used for complementary DNA (cDNA) synthesis with the Reverse Transcription TaqMan MicroRNA Reverse Transcription Kit  according to the manufacturer's instructions. The reverse transcription reaction was then diluted with water (1:3 ratio), and 2 µL was used for quantitative RT-PCR (RT‐qPCR) with specific TaqMan miRNA assays (Applied Biosystems®). Relative miRNA concentrations were calculated using the 2-dCq method with miR-486-5p as an internal standard (dCq = Cq[miRNA]-Cq[miR-486-5p]), as previously described RNA was isolated from 150 µL of plasma per sample with the miRNeasy Serum/Plasma Kit  as described by the manufacturer. Synthetic cel-miR-39-3p . The two-tailed significance level was set at p<0.05.st tertile, >median, >2nd tertile). Adjustment variables included all those used for matching performed in phase I: age, gender, region, BMI, KT/V, albumin, hsCRP, history of CVD and history of diabetes. Missing values were reported in phase II for the following continuous variables: KT/V, BMI, albumin and hsCRP. For this reason, adjusted associations between miRNAs and the endpoint were assessed using three different methods: complete observations , imputation by the median value and Multiple Imputation Chained Equation (MICE) Continuous variables were described as median (interquartile range) and categorical variables as frequencies (percentages). Comparisons of baseline characteristics and miRNA levels between the two populations (phase I and phase II) and between controls and cases in each phase were carried out using non-parametric Wilcoxon test for continuous variables and Fisher's exact test or chi-square test for categorical variables. Heat map of unsupervised hierarchical clustering and principal component analysis (PCA) were used to determine whether the miRNA profile could differentiate between cases and controls , with IR the incidence rate of the population and IRi and ni the incidence rate and the sample size on the i-th final node, respectively  was used for these statistical analysis including the survival In order to study the potential impact of the miRNAs in surrogate or high-order interaction fashion, we performed regression tree models. Particularly, we applied the CART algorithm Figure 1. The patient demographics and clinical characteristics for each phase are presented in the . miRNA sequencing was performed in randomly selected subgroups of cases and matched controls from phase I using HTG EdgeSeq miRNA WTA Assay technology. One sample (control group) did not pass the quality control and was discarded from further analysis. miRNA candidates were selected according to the following criteria: ≥2.5-fold differential expression and test significance cutoff of p-value less than 0.05. Seven circulating miRNAs met the established criteria: miR-506-5p, miR-513a-5p, miR-632, miR-1197, miR-4446-5p, miR-4765 and miR-6853-5p. As shown in the Figure , the levels of the seven candidates clearly separated cases and controls.The study flowchart is presented in  Figure E.To corroborate the miRNA sequencing results, we further evaluated the differentially expressed miRNAs by RT-qPCR, the gold standard for circulating miRNA analysis, in a training sample set of 24 cases and 24 matched controls from phase I (including the samples used for miRNA sequencing). We retained miRNAs with a Cq<35 and test significance cutoff of p-value less than 0.05. Six out of seven miRNAs were below the limit of detection in more than 80% of samples  and were discarded for further analysis. Plasma levels of miR-632 showed stable expression and higher levels in the event group; thus, supporting the sequencing resultsTable 1, a higher proportion of cases above the median level of miR-632 was observed when compared to patients with no reported event. In addition, miR-632 (>1st tertile and >median) was directly associated with the endpoint, even after adjusting for matching variables Table . Based on these findings, miR-632 was considered as a candidate biomarker for cardiovascular risk in patients on HD.Next, we quantified miR-632 in the whole phase I population using RT-qPCR. Due to the low number of miRNA candidates, two additional miRNAs, miR-186-5p and miR-210-3p, known to be associated with cardiovascular risk Table , there were no association between miRNAs and the endpoint in Cox regression models Table  and the AUC were low to modest Table . Similarly, no associations were found for miR-186-5p and miR-210-3p, neither in phase I, nor in phase II.Next, miR-632 was tested in the phase II cohort (unmatched population). miRNA levels were comparable in cases and controls Despite the promising findings in phase I with regard to miR-632, results from phase II suggested that circulating miRNAs were not, or were weak, biomarkers for risk stratification in HD patients. We have recently proposed the potential of the miRNA profile to define specific subpopulation of patients in the context of CVD Figure 3 shows the decision tree generated in the phase II population. Circles represent the whole follow-up and the different colors represent the free-event percentage of the patients in the node at that moment. For instance, a totally green circle indicates that 100-80% of the patients within this node do not experience the event during the follow-up. Accordingly, if half of the circle is green and the other half is dark blue, 20% of patients in that node are expected to experience the event during the first half of the follow-up while among an additional 0-20% of them are expected to experience the event during the second half of the follow-up. The percentage of survival at the end of follow-up is above 60%. In node 11, more than 80% of the patients are expected to suffer the event before the third year of follow-up. CART modeling revealed two circulating miRNAs, miR-186-5p and miR-632, that entered at the third level of the regression tree by redefining two risk groups: those patients older than 64 years and with hsCRP<0.827 mg/L and those diabetic patients younger than 64 years. The IR for the final nodes were 6.33, 21.17, 23.66, 101.57, 13.21, 25.75, 31.28 and 79.40. IR values above 100 indicate that all the patients experiment the event before the first year of follow-up. The IRV is 11.63 [8.72-19.24]. Survival Kaplan-Meier curves and hazard ratios from the Cox model for the eight patient subgroups  defined by the regression tree model are shown in Figure . The iAUC was 0.73 [0.67-0.79], ranging between 0.66 and 0.75 . The inclusion of miRNAs allowed a better discrimination during the first two years of the follow-up compared to regression tree models without miRNAs, the difference ranged from iAUC=0.68 for the clinical variables to iAUC = 0.71 for the clinical variables + miRNAs.Figure B. In particular, miR-210-3p had an importance similar to hsCRP, although it was not included in the model since hsCRP was already selected. All miRNAs showed a higher importance compared to other components of the AURORA Risk Score such as albumin, history of CVD and history of diabetes.The predictor importance of the variables ("variable importance" index) measures the relevance of the variables in a particular model taking into account the potential use as surrogate variables; the role that the variables would play if the main variable was unknown and could not be included in the model. The variable importance analysis revealed the potential of miRNAs as surrogate variables Since the original objective of the AURORA clinical trial was to analyze the impact of rosuvastatin on clinical outcomes, an additional analysis was performed after inclusion of statin therapy as predictor. Rosuvastatin use was not selected by the regression trees; and therefore, did not interfere with our findings.Regression tree models suggest the utility of circulating miRNAs in the identification of specific cardiovascular risk profiles among patients with end-stage renal disease receiving maintenance HD.Initially, we examined miRNAs as biomarkers for risk stratification in HD patients from phase I (matched) and phase II (unmatched). The results from phase I were promising since miR-632 levels were higher in the event group and were independently and directly associated with the endpoint. However, these findings were not confirmed in the phase II validation cohort. In this phase, miR-632 levels were indifferent in both study groups, were not associated with the outcome and, supporting previous data from our group,This study does not only offer additional insights into the potential of circulating miRNAs as biomarkers of cardiovascular risk but also suggest regression tree modeling as an optimal strategy in risk assessment. The advanced statistical technique applied herein revealed eight cardiovascular risk profiles, unknown a priori, based on the predictors considered among our patient population. Regression tree models could be of particular importance in heterogeneous populations, such as HD patients, and conditions in which the conventional risk factors are relevant (e.g. age), but additionally, it could be interesting to define risk subgroups based on other predictors (e.g. miRNAs), such as in cardiovascular risk prediction. By adapting reported indices and plots on the particular problem requirements, regression tree models also emerge as an interesting strategy in the development of biomarkers. The model selected miRNAs as predictors particularly relevant for specific subgroups of individuals whose discriminative power was diluted and of no use for risk assessment when analyzing the whole population.CVD is the largest contributor to mortality in patients undergoing HD Our results may be of clinical value. Different strategies for patient care, monitoring and treatment can be implemented depending on the risk. A tool to estimate the individual probability of adverse outcome may also be useful for patient selection in clinical trials. In the current study, the eight final nodes of the tree model were composed by subgroups of HD patients with specific clinical and miRNA patterns and marked differences in cardiovascular risks. We suggest that specific disease phenotypes are associated with different risk levels. Thus, cardiovascular risk assessment in patients on HD could be performed in a more personalized approach and should avoid the classical “one disease fits all”. CART modeling created four new subgroups of risk based on miRNAs, which ultimately hold potential to facilitate medical decision-making. We identified one subgroup of very high-risk individuals who may benefit most from adapted intensive monitoring and care . Conversely, we defined a subgroup of HD patients with low-risk status  in which unnecessary overtreatment should be avoided. Further investigations on the additional benefit of miRNA-based strategies in cardiovascular risk assessment and individualization of decision-making to specific patient subpopulations are warranted.The fact that miRNAs were associated with cardiovascular events in regression tree models could provide biological insights into disease mechanisms. In the context of atherosclerotic-disease, the cardiomyocyte-enriched miR-186-5p promoted macrophage lipid accumulation and pro-inflammatory cytokine secretion In conclusion, regression tree modeling suggest that the circulating miRNA profile complements conventional predictors in risk stratification and allows the identification of specific cardiovascular risk patterns among patient with end-stage renal disease receiving maintenance HD.The present study has several strengths. We used a high-quality database based on a large cohort of well-phenotyped HD patients from 280 nephrology centers in 25 different countries. The total sample size was 810 patients, one of the highest sample sizes used in studies focused on the evaluation of non-coding transcriptome as a source of cardiovascular biomarkers, and particularly miRNAs. The retrospective nature of the study constitutes a key limitation. The regression tree model needs to be externally validated in prospective studies. Only 7 of all the 2083 candidates included in the miRNA sequencing were further tested in the training set. From these 7 candidates, only miR-632 was tested in the whole cohort. Other miRNAs may be potential biomarkers of adverse outcomes. The sample size in the screening phase and training set is small. However, it fits with the recommendations for this type of studies Supplementary.Click here for additional data file.


Staphylococcus aureus (MRSA) in nursing homes poses a serious and escalating challenge to public health administration in infection control. Nursing homes are considered as major reservoirs for MRSA colonization, with considerable high levels of colonization prevalence. We employed a computation model to evaluate effects of three intervention scenarios on MRSA colonization prevalence rate in nursing homes. Simulations were conducted using a deterministic compartmental model featuring heterogeneous contact matrix between residents and health-care workers (HCWs). Contact parameters were derived from a nursing home survey. Three intervention scenarios were simulated: (1) hand-hygiene compliance by HCWs, (2) screening-and-isolation upon admission, and (3) implementing both interventions at the same time. For every 10% reduction in average contamination duration in HCWs, the estimated average reduction in prevalence rate was 1.29 percentage point compared with the prevalence rate before the intervention was implemented. Screening-and-isolation intervention resulted in an average reduction of 19.04 percentage point in prevalence rate . In intervention scenario 3, synergistic effects were observed when implementing hand-hygiene compliance by HCWs and screening-and-isolation together. Our results provide evidence showing that implementing multiple interventions together has a synergistic effect on colonization prevalence reduction.The endemic threat of methicillin-resistant  Staphylococcus aureus (MRSA) is a multi-drug resistant strain of Staphylococcus aureus, and is regarded as one of the major AMR pathogens. Among the 18 drug-resistant threats identified by the United States Centers for Disease Control and Prevention, MRSA is regarded as a serious threat, where patients in healthcare settings frequently have severe or potentially life-threatening infections [Antimicrobial resistance (AMR) has become one of the major pressing public health threats and challenges globally. Antibiotics are widely used to combat life-threatening bacterial diseases. However, the imprudent use of antibiotics contributes to resistance among pathogenic microorganisms which in turn threatens the effective treatment of bacterial, parasitic, viral, and fungal infection. Methicillin-resistant MRSA is commonly associated with the morbidity and mortality among elderly individuals. The overall incidence rates of MRSA infection among elderly individuals were consistently highest among other age groups globally ,3,4. ItsThe endemic threat of MRSA in nursing homes along with the trend in global population aging pose a serious and escalating challenge to public health administration in infection control. Compared to acute care hospital settings, little was known about the epidemiology of MRSA in nursing homes. A primary effort in MRSA control of nursing homes is to drive down the endemic prevalence rate. Two key MRSA infection control measures for nursing-home are hand-hygiene by healthcare workers (HCWs) and screening followed by isolation for residents upon their admissions. One of the concerns for nursing homes’ administration is how to evaluate effectiveness among different interventions in reducing the colonization prevalence rate. As a natural experiment studying infectious diseases transmission is neither possible nor ethical, computational modelling becomes an essential tool to simulate how infectious diseases progress and to evaluate the impact of infection control policies with different intervention implementations.The major transmission mode of MRSA infections is through direct contact with wounds, discharge, and soiled areas . A recenThe results of the simulations in intervention scenario 1, hand-hygiene compliance for HCWs, are summarized in The results of the simulations in intervention scenario 2, screening-and-isolation upon admission, are illustrated in The results of the simulations in intervention scenario 3, implementing both interventions at the same time, are illustrated in Close contact is the major transmission route of MRSA infections. The primary considerations in this study are how to represent the heterogeneity of contact mixing between residents and HCWs in the model, and the availability of social contact matrix data for parameters estimation. The modeling framework of this study employed explicit representation of the heterogeneous contact mixing between residents and HCWs. The contact parameters of this study were estimated based on the results of a nursing home survey conducted for residents and HCWs of 53 nursing homes. These approaches provide more legitimate simulation results of MRSA transmission in nursing homes. The model and methodology of this study also provide an instantaneous framework to evaluate hypothetical scenarios and to conduct “what-if” analyses. Nursing home administrators can employ the methodology of our study to make informed judgment and decision on infection control strategies accordingly.Our simulation results suggest that the two simulated interventions, (1) hand-hygiene compliance for HCWs and (2) screening-and-isolation upon admission, are effective in driving down MRSA colonization prevalence. Quantitative data shows that every 10% reduction in average contamination duration for HCWs results in a reduction of 1.29 percentage points in prevalence on average. The screening-and-isolation upon admission intervention was also shown to be effective in driving prevalence down, with a 19.04 percentage point reduction on average. In intervention scenario 3, a synergistic effect is observed when implementing both interventions together. The magnitude of effect in prevalence reduction in scenario 3 is larger than the sum of the magnitude of effect in scenarios 1 and 2. The synergistic effects observed by implementing both interventions together in scenario 3 is quite encouraging. We are not aware of any evidence showing this kind of synergistic effect in prior literature. This result should be brought to broader attention as hand-hygiene based intervention is relatively convenient to be implemented and is shown to be effective in bringing down MRSA colonization prevalence. Our simulation results provide quantitative data for nursing home administrators in interventions planning, design, adjustment, and effect estimation and comparison.To the best of our knowledge, the latest systematic review about MRSA transmission control in nursing homes was conducted in 2013 . One cliThe three prior clinical studies evaluating MRSA transmission control in nursing homes employed different intervention strategies, including hand-hygiene training program for HCWs, screening-and-isolation, and environmental cleaning. The study by Baldwin et al.  employedHand-hygiene intervention in health-care settings is beyond merely providing hand-hygiene facilities and implementing policy for HCWs. A prior study  reportedA two-level compartmental model with deterministic framework was employed. Nursing home residents are considered as hosts of MRSA, and HCWs are considered as transmission vectors. Residents are categorized into two mutually exclusive states: (a) uncolonized or (b) colonized; whereas HCWs are categorized into two mutually exclusive states: (c) contaminated or (d) uncontaminated. The model features the residents’ admission from community/hospital and discharge/death of the residents who are susceptible and colonized. Different routes of transmission were taken into account via the close contact among HCWs and residents: (i) HCWs-residents contacts, (ii) residents-residents contacts, and (iii) residents-HCWs contacts. Two types of transmission were defined in the model: Colonization and Contamination. MRSA can be transmitted to uncolonized residents by contact made with colonized residents or contaminated HCWs. Uncontaminated HCWs can be contaminated by contact made with colonized residents. Schematic of the transmission model is illustrated in U(t), C(t), H(t), and cH(t) denote the population size of uncolonized-residents, colonized-residents, uncontaminated-HCWs, and contaminated-HCWs, respectively in a nursing home at time t; 1/μ denotes the mean duration of contamination, while 1/ω denotes the mean duration of colonization. Nr denotes the population of residents and Nh denotes the population of healthcare-workers, where Nr = U(t) + C(t) and Nh = H(t) + Hc(t).The model is described with the following set of nonlinear differential equations:u and γc, respectively. Residents are admitted at the rate of Λ, and the probability of admitted residents being colonized is λ. It is assumed that the number of residents and HCWs remain constant, and the occupancy rate is 100%. Therefore, residential admission rate equals to residents’ discharge rate; i.e., Λ = γuU + γcC.The average length of stay of colonized residents and uncolonized residents are denoted by γr-r and βh-r denoted the residents-to-residents transmission rate and HCWs-to-residents transmission rate respectively, whereas βr-h denoted the residents-to-HCWs transmission rate. The values of these three transmission rates were defined as the estimated number of contacts multiplied by the transmission probability via contact, as summarized in r-r, ar-h, and ah-r denote the average number of residents-to-residents contact, residents-to-HCWs contact, and HCWs-to-residents contact, respectively; pr-r, pr-h, and ph-r denote the transmission probability via residents-to-residents contact, residents-to-HCWs contact, and HCWs-to-residents contact, respectively.Three transmission rates were defined in the model. βFourteen parameters were incorporated in the model. Values of 12 of the 14 parameters were identified in the parameterization process. Values of 2 parameters cannot be identified and were estimated. No best estimates of two key parameters were identified from prior studies: (a) transmission probability via residents-to-residents contact and (b) transmission probability via HCWs-to-residents contact. We estimated these two parameters by fitting the mathematical transmission model to the prevalence data. Four MRSA point-prevalence rates and their 95% confidence interval (CI) of nursing homes in Hong Kong were identified from prior studies  30,34,3,36. We dSimulations using the computational model described in the previous section were conducted by varying the two unknown transmission probabilities and the prevalence of Day 1. The combinations of the three variables used in the simulations are constructed based on 3-dimensional hypercube, varying the two transmission probabilities from 0% to 100% (with 0.1% increments) and the prevalence of Day 1 from 16.2% to 19.4% (with 0.1% increment); 33,066,033 simulations (1001 × 1001 × 33) were conducted. Each simulation was conducted to simulate prevalence for 2500 days where the prevalence rates reached equilibrium. Of the 33,066,033 simulation generated results, 487 fitted within the 95% confidence interval of the four point-prevalence rate on their respective day. These 487 sets of parameters were used to further conduct simulations of interventions. Three types of intervention scenarios were evaluated using the computational model: (1) hand-hygiene compliance by HCWs, (2) screening-and-isolation upon all admission, and (3) implementing both interventions at the same time. Assuming interventions implemented on Day 2501, we simulated the long term impact of different hypothetical intervention scenarios on MRSA transmission dynamics. The 487 sets of parameters that fitted within 95% CI of the four point-prevalence rates were used as the input parameters for the computational model. Effects of interventions were evaluated by comparing the point prevalence of Day 2500 and Day 7500 for each of the simulations.Hand-hygiene compliance by HCWs was simulated by reducing the average contamination duration 1/μ. Five levels of hand-hygiene compliance by HCWs were evaluated by reducing the average contamination duration by 10%, 20%, 30%, 40%, or 50%. Computational model defined in the previous section was used to simulate effects of hand-hygiene by HCWs compliance to prevalence in our study; 2435 simulations (5 levels of compliance ×487 set of parameters) were conducted for this scenario.The model was further extended in order to study effects of screening-and-isolation upon admission to prevalence rate. We assumed a 100% screening success rate, a 5-day isolation period, and a 100% decolonization rate after 5 days in isolation. An additional compartment was added in the model in order to represent the screening-and-isolation upon admission. All colonized admissions were put into an isolation compartment I, and they were forwarded to compartment U after 5 days. Schematic of the extended model is illustrated in Simulation of intervention scenario 2 was run with five levels of hand-hygiene compliance by HCWs ; 2435 simulations were conducted for this scenario.We presented a computational model with heterogeneous social contact mixing to simulate the transmission of MRSA in nursing homes. This approach can be used to conduct scenario analyses for MRSA transmission in nursing homes, and can also be generalized to other settings including hospitals and households as well as multi-drug resistance organisms such as extended spectrum beta-lactamases and Carbapenem-resistant enterobacteriaceae. Several limitations of the study are noteworthy. First, the potential super-spreading events and transmissibility variation in individual or sub-groups were not considered in this model. Second, this study mainly employed the survey data of nursing homes in Hong Kong to parameterize the model. Region or country specific data including point prevalence, characteristics of nursing home, and social mixing matrix is needed to study the situations in different countries/regions. Finally, we are not aware of any prior study about the efficacy of MRSA screening and decolonization of nursing homes and 100% efficacy was assumed in this study. Further study is needed to parameterize these two factors accurately.


Colorectal cancer is the third most common cancer in the world with increasing incidence and mortality rates globally. Standard treatments for colorectal cancer have always been surgery, chemotherapy and radiotherapy which may be used in combination to treat patients. However, these treatments have many side effects due to their non-specificity and cytotoxicity toward any cells including normal cells that are growing and dividing. Furthermore, many patients succumb to relapse even after a series of treatments. Thus, it is crucial to have more alternative and effective treatments to treat CRC patients. Immunotherapy is one of the new alternatives in cancer treatment. The strategy is to utilize patients’ own immune systems in combating the cancer cells. Cancer immunotherapy overcomes the issue of specificity which is the major problem in chemotherapy and radiotherapy. The normal cells with no cancer antigens are not affected. The outcomes of some cancer immunotherapy have been astonishing in some cases, but some which rely on the status of patients’ own immune systems are not. Those patients who responded well to cancer immunotherapy have a better prognostic and better quality of life. Colorectal cancer (CRC) is the third most common cancer in the world with an incidence of 10.2% and a mortality rate of 9.2% of all cancers . In deveStandard conventional treatments for CRC are surgery, chemotherapy and radiotherapy. Depending on the localization and progression of the disease, these treatments can be used in combination –8. TotalCancer immunotherapy is one of the new alternatives in cancer treatment. In comparison to the standard treatment, this treatment manipulates and utilizes patients’ own immune system in combating the cancer cells. The innate and adaptive immune responses are alerted to recognize the cancer cells and potentially eradicate the tumor –18. ManyStreptococcus pyogenes  are immunoglobulin molecules, which are made up of antigen-binding fragments that are connected to a constant region with two identical light and heavy chains. The light chains are made up of one variable and one constant domain while the heavy chains consist of one variable and three constant domains . There iin vitro cell-based technology  and Food Drugs Administration (FDA) for therapeutic use (status 2017) . Table 1One of the common immunomodulatory mAbs is immune checkpoint inhibitors (ICIs). The ICIs are used to target and/or block immune checkpoints protein ligands on T cells surfaces or other immune cell subpopulations in restoring immune function. The immune checkpoints serve as key regulators that serve as an immune brake when there is sufficient immune response. However, in cancer, there is high activation and overexpression of immune checkpoints leading to suppression of anti-tumor immune response that favors malignant cell proliferation and spread , 81.The most widely studied immune checkpoint targets are programmed cell death 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA4) due to their overexpression and abundance in various solid tumors and hematological malignancies . NeverthIn colorectal cancer, three FDA-approved ICIs drugs are targeting PD-1 and CTLA-4 . HoweverCytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is one of the immune checkpoints that serve as co-inhibitory receptors on the T cell surface . The rolProgrammed death 1  is a novel member of the immunoglobulin gene superfamily (IgSF) with restricted expression in the thymus of mice . The PD-In humans, the PD-1 (PDCD1) gene is located at 2q37.3 which encodes for PD-1 proteins . This prProgrammed death 1 binds to two ligands, PD-L1  and PD-L2  with differential expression . This biSimilar to CTLA-4, the main role of PD-1/PDL1 interaction (PD-1 pathway) under normal conditions is as a brake for immune response in which the pathway can limit T-cell effector responses. One of the ways is through enhancing immunosuppressive regulatory cells (Tregs) development, thus prevent over-activation of the immune response in human peripheral tissues . This imHowever, this is not always the case in cancer. Overexpression of PD-1 is observed that leads to constant PD-1 (on the T cell surface) binding to its ligand, PDL1 (on the cancer cells). As a result, PD1/PDL1 signals are constitutively high, suppress the activation of T cells and cause antigenic tolerance. This allows immune cell evasion by cancer cells which then support the high tumor proliferation rate , 115. Th®), a humanized monoclonal IgG4 antibody, used in treating melanoma  that shows durable responses among the dMMR metastatic CRC (mCRC) cohort of patients. Approximately, 69% of these patients have 12 months of overall survival (OS) . Results show the progression-free survival rate up to 78% compared to mismatch-repair proficient, microsatellite stable (pMMR/MSS) patients of 11% . Anotherval (OS) . Interesval (OS) .Adoptive cell transfer is a cell-based therapy that uses cells either from the patient (autologous transfer) or other donors  to improve immune function . There aAdoptive cell transfer that uses TILs (ACT-TIL) was first successfully observed in 60% of metastatic melanoma patients who had not been treated with interleukin-2 (IL-2) and 40% of non-respondents IL-2 treatments which resulted in cancer regression . Howeverex vivo and genetically modified through the insertion of the chimeric antigen receptor (CAR) onto the T cells as CAR-T cells  such as CD19 in diffuse large B cell lymphoma (DLBCL)  , interle (DLBCL)  and epid (DLBCL)  and carc (DLBCL)  to promo (DLBCL) . The adv-T cells , 134. Fu-T cells , 136.∗0201–restricted peptide in melanoma-associated antigen (MAGE)-A3. This approach had caused severe damage to gray matter in the brain as the TCR recognized a different but related epitope that was expressed at low levels in the normal brain cells . Furthermore, toxicity is the main issue when targeting antigenic targets such as TAA which are also expressed on normal tissues but are overexpressed on the tumor. An example of these cross-reactivities was seen in CAR-T cells targeting HLA-Ain cells . Anotherin cells . Other sin cells  but mostIn CRC, CAR-T cells target carcinoembryonic antigens (CEA) and guanylyl cyclase C (GUCY2C) , 143 tumHowever, some limitations are encountered in effective targeting of solid tumors by CAR-T cells. This explains why CAR-T cells have not proceeded into commercialization and approval for solid tumors. One of the challenges is the efficient trafficking and infiltrating of solid tumors. The microenvironment of solid tumors contains an abundant fibrous matrix and immunosuppressive cells, which protects the tumor tissue and resists immune cell attack. This includes certain chemokines such as CXCL1, CXCL12, and CXCL5 that are secreted by the tumor cells to inhibit the effective delivery of the CAR-T cells , 153. ThModification of T cell receptors (TCR) is another approach for ACT and it is known as TCR transduced therapy. It is quite similar to CAR-T cells but their mechanisms for recognizing antigens are quite different. In CAR-T cells, antibody fragments are employed to bind the specific antigens on the surface of cancer cells. In contrast, TCRs use heterodimers consisting of alpha and beta-peptide chains to recognize polypeptide fragments presented by MHC molecules . This alIn TCR-T cell therapy, the MHC-dependent allows more antigen targeting compared to CARs. These antigens include MART-1, Gp100, CEA, NY-ESO-1, MAGE-A3, MAGE-A4, and others, which are suitable for TCR-T cell therapy . In addiNormally, the affinity of human TCRs toward cancer antigens is relatively low, which makes it impossible to recognize and kill tumors effectively. With the advance of engineering technology, genetically-modified TCR is encoded in T cells that give it better specificity and affinity toward cancer antigen. For example in the multiple myeloma patients, TCR was engineered through modifications of several key amino acids in order to have a higher affinity for cancer antigens, NY-ESO-1 . The cliT cell receptors therapy although it is a very promising approach comes with many challenges including good targets selection, specific TCRs search, optimal TCR affinity screening, safety evaluation, time and cost . In addiCancer cells express altered self-antigens that induce weaker responses compared to foreign antigens such as infectious agents. Often, immune stimulants and adjuvant are incorporated together with the cancer vaccines to enhance the effects. Cancer vaccine includes autologous patient-derived immune cell vaccines, tumor antigen-expressing recombinant virus vaccines, peptide vaccines, DNA vaccines and heterologous whole-cell vaccines derived from established human tumor cell lines .Preventive (prophylactic) and therapeutic are the approaches of cancer vaccines treatments in which preventive cancer vaccines intended to minimize cancer incidence, morbidity and mortality while therapeutic vaccines aimed to treat current malignancies and may prevent , 170. To® (Sanofi) , particularly non-muscle invasive bladder cancer (NMIBC) subtype. Results showed that approximately 74% of the patients showed a complete response with BCG compared to Doxorubicin  and Tice . However, due to the supply shortage of TheraCys®, it was discontinued and replaced by TICE®. Nevertheless, a study conducted previously shows that treatments using different BCG strains among NMIBC patients have a significant role as BCG Connaught treatment was more effective than BCG Tice in terms of 5 years recurrence-free survival rate (The first FDA approved cancer vaccine was TheraCys(Sanofi) . It is aorubicin . This vaorubicin . At the val rate . Furtherval rate .Another FDA approved therapeutic vaccine is Sipuleucel-T  which used to treat prostate cancer patients who are asymptomatic or minimally symptomatic metastatic castration-resistant. This vaccine uses the patient’s own immune cells  isolated through leukapheresis. The immune cells were cultured and incubated with PA2024, a fusion protein made up of prostatic acid phosphatase (PAP) which is linked to granulocyte-macrophage colony-stimulating factor (GM-CSF) as the adjuvant , 176. An®, Amgen Inc.) is the latest FDA approved vaccine to treat unresectable cutaneous, subcutaneous, and nodal lesions melanoma recurrent before initial surgery  . A. A208). In this review, we provide an overview of the novel trends in the immunotherapy field that are yielding therapeutic benefits in CRC patients. We summarize the advantages and drawbacks of each type of immunotherapy in NJ and NS contributed to the conception and design of the study. NS wrote the first draft of the manuscript, looked for the raw material and summarize the findings, and constructed the diagrams and tables. NJ did the final editing and final input of ideas. Both authors contributed to manuscript revision, read and approved the submitted version.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.


The coronavirus disease 2019 (COVID-19) results in hypoxia in around a fifth of adult patients. Severe hypoxia in the absence of visible respiratory distress (‘silent hypoxia’) is increasingly recognised in these patients. There are no published data evaluating lowest recorded pre-hospital oxygen saturation or pre-hospital National Early Warning Score 2 (NEWS2) as a predictor of outcome in patients with COVID-19.In this retrospective service evaluation, we included adult inpatients with laboratory confirmed COVID-19 who were discharged from hospital or who died in hospital between 12 March and 28 April 2020 (n = 143). Pre-hospital and in-hospital data were extracted and analysed to explore risk factors associated with in-hospital mortality to inform local triage and emergency management.The lowest recorded pre-hospital oxygen saturation was an independent predictor of mortality when controlling for age, gender and history of COPD. A 1% reduction in pre-hospital oxygen saturation increased the odds of death by 13% . Lower pre-hospital oxygen saturation predicted mortality after adjusting for the pre-hospital NEWS2 . The pre-hospital NEWS2 was higher in those who died  than in those who survived to discharge .This service evaluation suggests that the lowest recorded pre-hospital oxygen saturation may be an independent predictor of mortality in COVID-19 patients. Lowest pre-hospital oxygen saturation should be recorded and used in the assessment of patients with suspected COVID-19 in pre-hospital and emergency department triage settings. In December 2019, the novel coronavirus SARS-CoV-2, and resulting coronavirus disease 2019 (COVID-19), emerged in mainland China. It was declared a Public Health Emergency of International Concern on 30 January 2020, and was confirmed as a pandemic by the World Health Organisation on 11 March 2020.COVID-19 causes a wide spectrum of clinical presentations. The majority of patients develop mild symptoms, predominantly fever and cough , while 2While multiple severity scoring systems exist for the critically unwell patient, few have been validated for use in COVID-19. These often require a detailed medical history, laboratory results or radiological findings, which take time and require healthcare professionals to be patient-facing . HoweverIn response to the pandemic, significant changes were made to the admissions process at our hospital, including the development of an Incident Triage Area (ITA) to receive all patients brought by ambulance. They were streamed rapidly to COVID-19-suspected or non-COVID-19 areas by senior Emergency Department (ED) clinicians who used clinical judgement in the absence of a formal decision-making algorithm. A retrospective service evaluation was undertaken of patients admitted to hospital who tested positive for COVID-19 to inform local triage and explore risk factors associated with mortality. Further scrutiny of patients who were triaged to non-COVID-19 areas led to the identification of pre-hospital hypoxia as a ‘red flag’ in our population. To our knowledge, few papers have yet been published on the clinical parameters of patients with COVID-19 in the pre-hospital setting.This retrospective service evaluation included adult inpatients (≥16 years old) from an inner-city University Hospital in South West England. Of patients presenting to the ED with respiratory symptoms (either by ambulance or self-presenting), those who required hospital admission received a SARS-CoV-2 RNA PCR test. All adult patients who were diagnosed with COVID-19 by testing positive on SARS-CoV-2 RNA on PCR at any point during their admission, and had been discharged or died between 12 March 2020 and 28 April 2020, were included in this study. Data were collected broadly to inform local clinical decisions and services, with a specific interest in the effectiveness of our ITA established from 17 March 2020.This study was performed as part of a service evaluation. Analysis of routinely collected retrospective clinical data was performed to determine whether any parameters could be correlated with recovery of this patient cohort and be used to improve service delivery for this patient group. All data are presented as anonymised collated data. Research Ethics Committee approval was not required.Neither patients nor the public were involved in the design, conduct, reporting or dissemination plans of our service evaluation.Epidemiological, demographic, clinical, laboratory, treatment and outcome data were extracted from electronic and paper medical reports using a centralised database, REDCap. All data were checked and entered by two physicians. Follow-up was triggered by REDCap notification of incomplete outcome data and carried out continuously during the period of data collection.p value was <0.05. Continuous and categorical variables were presented as median (Interquartile Range (IQR)) and n (%) respectively.Following data extraction into Excel, demographics, clinical information and in-hospital mortality were presented. Data were analysed in Stata 14 and results were defined as statistically significant if the Analysis of the lowest pre-hospital recorded saturation  was performed for those patients arriving at hospital by ambulance from 12 March 2020 (excluding patients who contracted COVID-19 as an inpatient and those self-presenting).Logistic regression was used to examine the relationship between the lowest pre-hospital oxygen saturation and in-hospital mortality adjusting for age, gender and COPD. A separate logistic regression model included the pre-hospital NEWS2, but numbers were not sufficient to adjust for age, gender and COPD.Kaplan Meier curves were produced for all patients admitted to this hospital with a positive SARS-CoV-2 RNA PCR test up to 28 April 2020, and included all patients whether or not their outcome was known. Pre-hospital oxygen saturation values were divided into four categories, and a separate curve was produced for each category. Patients without a known outcome by 28 April 2020 were censored on this day and patients who were transferred to another unit were censored on the day of transfer, giving a larger data set of n = 133 . The Kaplan Meier graph for time to death censored patients on the date of discharge, and the graph for the time to discharge censored patients on the date of death. Log rank tests were used to test for associations with the categorised pre-hospital oxygen saturation values.Two physicians were used to review patient records and enter data to ensure accuracy. Patients were identified for data collection by laboratory-confirmed infection rather than clinical suspicion. To ensure inpatient COVID-19 infection could be identified and excluded, data were collected on means of arrival at hospital, location the patient was first assessed, day of COVID-19 symptoms at admission, maximum level of care received and date of outcome. When analysing results, we controlled for anticipated confounding variables through logistic regression.A total of 164 patients admitted to our university teaching hospital were diagnosed with COVID-19 and tested positive for SARS-CoV-2 RNA on PCR between 12 March 2020 and 28 April 2020. An outcome of either discharged from hospital or died in-hospital was determined for 143 patients by 28 April 2020. Of these, 109 patients arrived by ambulance and had ‘lowest pre-hospital oxygen saturation’ on air recorded by paramedics on arrival at scene. ‘Pre-hospital NEWS2’ was recorded in 87 patients on arrival at scene. The lowest recorded pre-hospital oxygen saturation was lower in those who died  74–87); n = 33) than in those who were discharged . This difference was statistically significant .There was no correlation between lowest recorded pre-hospital oxygen saturation and patient age  and no difference by gender (p = 0.7739 Mann-Whitney U Test). Patients with a past medical history of COPD presented with lower oxygen saturation  than those without COPD  (p = 0.0223 Mann-Whitney U Test).After adjusting for age, gender and a previous diagnosis of COPD, the lowest recorded pre-hospital oxygen saturations predicted death vs discharge , p < 0.001). This indicates a 13%  increase in the odds of in-hospital death for every 1% reduction in lowest recorded pre-hospital oxygen saturation.Time from admission to death was significantly associated with pre-hospital oxygen saturations , with a trend suggesting shorter survival time for those with lower pre-hospital oxygen saturation  .Ceilings of care were identified on admission for all patients during their inpatient stay. The lowest recorded pre-hospital oxygen saturation was lower in those who were intubated  60–86); n = 13) than in those who were not intubated . This difference was statistically significant .The number of patients intubated was too small for an adjusted analysis; unadjusted logistic regression shows a 9% increase in the odds of intubation  for every 1% reduction in the lowest recorded pre-hospital saturation (p = 0.001).The median time to intubation was 2 days (the day after admission). Six patients (46%) were intubated within 24 hours of admission.There is a weak negative correlation between length of stay and lowest recorded pre-hospital oxygen saturation for patients who were discharged (Spearman’s correlation = –0.3702 (n = 76), p = 0.001) . The KapThe pre-hospital NEWS2 was higher in those who died  than in those who survived to discharge . This difference was statistically significant . The pre-hospital NEWS2 was also higher in those patients who were eventually intubated  than those who were not intubated . This difference was also statistically significant .Every patient with a pre-hospital NEWS2 score of ≤5 was eventually discharged (n = 21). There was no statistical difference in length of stay for those with a pre-hospital NEWS2 score ≤5 or ≥6.Logistic regression shows that the lowest recorded pre-hospital oxygen saturation still predicts the odds of death after adjusting for overall pre-hospital NEWS2 . This suggests that lowest pre-hospital oxygen saturation predicts mortality independently from the NEWS2.Of interest, there was no statistical difference in respiratory rate between those who died  and those survived to discharge .Internationally, NEWS2 is the most widely used bedside scoring tool available and there is increasing evidence to demonstrate that its use in the pre-hospital setting can predict critical illness and improve patient outcomes . When inMany other scoring systems have been put forward as alternatives to NEWS2. A Pre-hospital Older Adult Warning Score proposed adding in factors such as lactate and the ratio of SpO2 to FiO2 and showed promising predictive values in a small cohort of Spanish patients, although it is unlikely to be taken up across the NHS where NEWS2 is so widely utilised and point of care lactate measurements are not readily available .NEWS2 has continued to be the predominant bedside score used during the pandemic. Recently, the Royal College of Physicians updated their NEWS2 guidance to emphasise the significance of escalating oxygen requirements in patients with COVID-19 irrespective of a change (or lack of change) in NEWS2 scores . Novel rOf note, NEWS2 may not place adequate significance on the derangement of a single parameter. Hypoxia and the use of supplemental oxygen can claim a maximum score of 5, where the highest theoretical NEWS2 score is 20. This service evaluation found that lower pre-hospital oxygen saturation was a predictor of in-hospital mortality from COVID-19, independent from NEWS2, age or gender, with a 13% increase in odds of in-patient mortality for every 1% fall in pre-hospital oxygen saturations. There is a paucity of published evidence around the significance of pre-hospital hypoxia in predicting critical illness or early mortality.2 to RR ratio in patients with acute respiratory failure and reported a significantly higher ratio in COVID-19 patients compared with non-COVID-19 patients  despite 28% of patients requiring supplemental oxygen . This ispatients . This ilFurthermore, early recognition of silent hypoxia in suspected COVID-19 allows prevention of nosocomial spread by the appropriate use of personal protective equipment and isolation. One case report describes the late recognition of COVID-19 in an atypical presentation  resulting in staff infection, despite the presence of significant pre-hospital hypoxia .The universal language of NEWS2 aims to standardise handover between clinical teams . ResearcThis study has several limitations. This is a single-centre service evaluation and the findings may not be generalisable to other clinical settings or regions with different local populations. The results from this study may be influenced by confounding factors inherent in the retrospective study design, such as information bias arising from inaccurate record keeping. Missing information further limits the effectiveness of handover and may impact patient care. Only patients brought in by ambulance are included in this article, which aims to represent patients with more severe disease but does not account for socioeconomic attitudes or physical barriers to accessing healthcare.In an attempt to obtain a true COVID-19 cohort, we included patients with laboratory PCR confirmed COVID-19 infection. However, a risk of selection bias cannot be overlooked as we did not include patients treated for clinical COVID-19 infection but with a negative PCR test. In an attempt to reduce this risk, we included those with a positive PCR result at any time during their admission (including those with a previous negative PCR result), but excluded those with hospital-acquired infection.Our retrospective service evaluation showed the lowest recorded pre-hospital oxygen saturation on arrival at scene to be an independent predictor of mortality in COVID-19 patients. Lower recordings are associated with an increased mortality and need for intubation, and a longer length of stay. This increased risk of mortality is independent of age, gender and a previous diagnosis of COPD, as well as the pre-hospital NEWS2 score. Lowest pre-hospital oxygen saturation should be recorded and used in the assessment of patients with suspected COVID-19 in pre-hospital and emergency department triage settings. Further research is required to validate these findings in prospective, multicentre studies.The authors acknowledge Mai Baquedano, Senior Research Associate, University of Bristol, UK; and Simon Laing, Consultant in Emergency Medicine, Bristol Royal Infirmary, University Hospitals Bristol and Weston NHS Foundation Trust, UK.Data were collected by KD, CH, ZC and PA. Material was drafted by KD, CH and ZC, and edited by PA and AL. Statistical analysis was performed by HT. The project was supervised by AL, who was also responsible for planning and conduct, and overall content. Each author has been involved in the development of the final material. AL acts as the guarantor for this article.None declared.Not required.None.


Excessive alcohol use is a leading cause of preventable death in the United States   Table 2Table 2. Alcoholic liver disease was the leading chronic cause of alcohol-attributable deathsoverall  and among males  and females  . PoisoniThe national average annual age-adjusted alcohol-attributable death rate was 28.0 per100,000, and the YPLL per 100,000 was 873.0 . The aveExcessive alcohol use was responsible for approximately 95,000 deaths and 2.8 millionYPLL annually in the United States during 2011–2015. This means that anaverage of 261 Americans die from excessive drinking every day, shortening theirlives by an average of 29 years. The majority of these alcohol-attributable deathsinvolved males, and approximately four in five deaths involved adults aged≥35 years. The number of alcohol-attributable deaths among adults aged≥65 years was nearly double that among adults aged 20–34 years.Approximately one half of alcohol-attributable deaths were caused by chronicconditions, but acute alcohol-attributable deaths, all of which were caused by bingedrinking, accounted for the majority of the YPLL from excessive drinking.Little progress has been made in preventing deaths caused by excessive drinking; theaverage annual estimates of alcohol-attributable deaths and YPLL in this report areslightly higher than estimates for 2006–2010, and the age-adjustedalcohol-attributable death rates are similar , could reduce alcohol-attributable deaths and YPLL. Thesestrategies can complement other population-based prevention strategies that focus onhealth risk behaviors associated with excessive alcohol use, such as saferprescribing practices to reduce opioid misuse and overdoses  and 2.8 million years of potential life lost  in the United States each year.Widespread implementation of prevention strategies, including thoserecommended by the Community Preventive Services Task Force  could help reduce deaths and years of potentiallife lost from excessive drinking.


Heatwaves kill more people than floods, tornadoes, and earthquakes combined and disproportionally affect older persons and those with chronic conditions. Commonly used medications for chronic conditions, e.g., diuretics, antipsychotics disrupt thermoregulation or fluid/electrolyte balance and may sensitive patients to heat. However, the effect of heat-sensitizing medications and their interactions with heatwaves are not well-quantified. We evaluated effects of potentially heat-sensitizing medications in vulnerable older patients.th percentile of historical zip code-specific surface air temperatures. We estimated associations of heat-sensitizing medications and heatwaves with heat-related hospitalization using self-controlled case series analysis.US Medicare data were linked at the zip code level to climate data with surface air temperatures for June-August of 2007–2012. Patients were Medicare beneficiaries aged ≥65 years with chronic conditions including diabetes, dementia, and cardiovascular, lung, or kidney disease. Exposures were potentially heat-sensitizing medications including diuretics, anticholinergics, antipsychotics, beta blockers, stimulants, and anti-hypertensives. A heatwave was defined as ≥2 days above the 95We identified 9,721 patients with at least one chronic condition and heat-related hospitalization; 42.1% of these patients experienced a heatwave. Heatwaves were associated with an increase in heat-related hospitalizations ranging from 21% (95% CI: 7% to 38%) to 33% (95% CI: 14% to 55%) across medication classes. Several drug classes were associated with moderately elevated risk of heat-related hospitalization in the absence of heatwaves, with rate ratios ranging from 1.16 (95% CI: 1.00 to 1.35) to 1.37 (95% CI: 1.14 to 1.66). We did not observe meaningful synergistic interactions between heatwaves and medications.Older patients with chronic conditions may be at heightened risk for heat-related hospitalization due to the use of heat-sensitizing medications throughout the summer months, even in the absence of heatwaves. Further studies are needed to confirm these findings and also to understand the effect of milder and shorter heat exposure. Over the last 50 years, an overall warming of the earth’s surface has resulted in both more frequent and severe extreme heat events ,2, whichSome classes of medications commonly used by older patients with chronic conditions may predispose these individuals to heat-related complications. These medications can sensitize a patient to heat by disrupting thermoregulatory responses that maintain core body temperature, either by interfering with cognitive processes or by directly disrupting autonomic mechanisms . For insBased on underlying pharmacology and findings from previous studies –19, we sWe identified a cohort of older patients with chronic conditions who were discharged from the hospital and characterized their medication use after discharge from June 1 to August 31 of 2007–2012. As some of the medication classes of interest are key treatments for the relevant conditions, we did not compare medication-receiving patients to untreated patients, to avoid intractable confounding by disease severity, access to healthcare, and frailty , which eThe study was approved by the Institutional Review Board of the University of North Carolina at Chapel Hill. Individual patient consent was not required for this analysis of HIPAA-limited secondary data.th Revision Clinical Modification (ICD-9-CM) codes for heart failure [We identified disease-based cohorts of patients aged ≥65 years among US Medicare beneficiaries with fee-for-service parts A, B, and D coverage who were discharged alive from the hospital with International Classification of Diseases 9 failure , myocard failure , diabete failure , or chro failure  from JunWe restricted our analyses to June-August in order to focus on the relatively short time periods when patients were exposed to higher temperatures and at greater risk of heat-related illness. Timing of most heatwave episodes tends to occur in late July and August, thus concentrating on these months is most appropriate ,27. We rWe identified heat-related hospitalizations during follow-up with ICD-9-CM diagnosis codes for heat-related illness –30 in anmax) above the 95th percentile of historical zip code-specific normal temperatures (reference period 1949–2010) [max data were obtained from the Meteorological Forcing Dataset for Land Surface Modeling for 2007–2010 [max to 43,191 zip codes across the United States. As heat effects may linger after the end of a defined heatwave, we added 14 days to the end of each heatwave period to capture potentially lagged heatwave-related events; additionally, if one heatwave’s grace period overlapped with the beginning of another heatwave event, we considered the two heatwaves as one continuous event.The risk of heat-related illnesses is likely to be influenced by heatwaves—short-term elevations above normal temperatures –33. Acco49–2010) ,36. Due 007–2010  and from007–2010 . We inteWe evaluated each individual’s medication exposure using Medicare pharmacy dispensing data from the index hospitalization discharge through August 31 of that year. Medication classes were selected based on prior data and pharmacologic mechanisms and included ACE inhibitors or angiotensin II receptor blockers (ARBs), antipsychotics, beta blockers, loop diuretics, anticholinergic medications, and stimulants . IndividPatient follow-up time from hospital discharge to August 31 of each year was divided into four exposure statuses based on medication and heatwave exposure . The rates of heat-related hospitalizations occurring during periods of medication use, heatwave exposure, or both combined were separately compared within individuals to rates during each patient’s periods of no medication or heatwave exposure . AnalyseSCCS analyses are exposure-anchored, case-only designs restricted to only those patients experiencing the outcome. All of a patient’s follow-up time (both before and after the outcome) contributes to the analysis . StandarWe identified 377,100 patients at hospital discharge having at least one of the comorbidities of interest . The finWithin individual comorbidity subgroups, the mean age of patients ranged from 76.7 years (SD 7.6) for diabetes mellitus to 83.8 years (SD 7.5) for dementia. The percentage of males varied from 31.5% for dementia and stroke to 41.4% for CKD, and the percentage of white patients ranged from 70.7% for stroke to 83.7% for MI. Heatwave exposure did not vary substantially across conditions .Of the heat-related hospitalizations observed during follow-up, 2,176 (22.4%) occurred during a heatwave period. The risk of experiencing a heat-related hospitalization was higher during heatwave periods, with RRs ranging from 1.21 (95% CI: 1.07 to 1.38) among ACE inhibitor/ARB users to 1.33 (95% CI: 1.14 to 1.55) among users of anticholinergic agents . CompariUse of several medication classes (except for beta blockers and stimulants) was associated with heat-related hospitalization during the summer months among cases in the overall cohort, even during non-heatwave periods. RRs for positive associations ranged from 1.16 (95% CI: 1.00 to 1.35) for anticholinergic agents to 1.37 (95% CI: 1.14 to 1.66) for antipsychotics . Among cRRs for periods when patients were exposed to both medication and heatwaves were not meaningfully higher than those for the periods with heatwave only or medication-only estimates, suggesting an absence of positive synergistic effects between heatwaves and medications on heat-related hospitalization .In sensitivity analyses using broader heat-related hospitalization as an outcome, the number of heat-related hospitalizations increased by 1,523 (16%) but the medication and heatwave distribution in the cases was similar . Rate raIn this SCCS analyses of older patients in the US with chronic conditions, heatwaves were associated with a 21% to 33% increased risk of heat-related hospitalization from June-August between 2007 and 2012. Use of medications that can potentially disrupt thermoregulatory responses which maintain core body temperature was frequent, ranging from 18% up to 71% except for stimulants (<1%). Exposure to these medications and exposure to heatwaves were both associated with increased risk of heat-related hospitalization. However, we found no meaningful, significant positive synergistic effects between heatwaves and most of the medications.The effect sizes observed in our study are in a range consistent with those reported in previous studies of heatwaves and heat-related hospitalization. Bobb et al. linked 100% Medicare inpatient data and daily temperature data from the National Climatic Data Center and found that heatwave exposure was associated with increased risk of hospitalization for fluid and electrolyte disorders  and heat stroke  . As our This national study evaluated older patients with chronic conditions from across the US treated in a variety of healthcare settings and experiencing a wide range of heat exposures. Findings showed that patients who experienced heat-related hospitalizations were more likely to experience them during periods of use of ACE inhibitors or ARBs, anticholinergic agents, antipsychotics, and loop diuretics. The observed increases in the risk of heat-related hospitalization among medication users are consistent with previous smaller studies of medication use and heat-related illness. However, studies supporting associations between medications and heat-related illness are limited to case reports , pharmacth percentile of historical temperatures, and it is possible that the medications under study may increase susceptibility to less extreme temperatures or shorter-lasting heat events in this vulnerable population. Results from the analyses of stimulant medications were based on fewer than 60 patients taking such medications in the overall cohort, with even lower numbers in the disease-specific cohorts, and therefore warrant further investigation in larger samples.We did not observe clinically meaningful synergistic effects between heatwave events and most of the medications. However, we did observe elevated rates of heat-related hospitalization associated with medication use throughout the warm summer months, even in the absence of prolonged extreme heat. Our heatwave definition did not capture extreme heat events lasting less than 2 days or below the 95This national study of Medicare data benefits from the use of the SCCS design, which inherently controls for between-person confounding by time-invariant factors . Our folOur study also has several limitations. Misclassification of drug exposures is possible, as we defined medication use from pharmacy dispensing data rather than direct observation of patient behavior. We may have overestimated or underestimated medication exposure due to non-adherence, early discontinuation, or our use of grace periods to define periods of continuous use. However, any exposure misclassification is likely to be non-differential and would thus lead to underestimation of the effect of medications on heat-related outcomes. We utilized a lag period in our heatwave definition to capture lagged events and concatenate adjacent heatwaves, but this may potentially introduce some misclassification of heatwave status. Our heatwave definition relied on zip code-level daily maximum temperatures at Medicare enrollees’ homes, though patient-level exposure to extreme heat may vary within zip codes. Patients may not be exposed to extreme heat at their home or current location due to travel or confinement to climate-controlled environments. For example, older patients with home health care or in a residential health facility may remain indoors and generally be shielded from outside temperatures, potentially illustrated by the generally reduced or null association of heatwave with heat-related hospitalizations among patients with stroke, who may be more frequently institutionalized or immobilized. However, the exact nature of patients’ heat exposure and home settings could not be inferred from our data. Accordingly, our findings may be subject to exposure misclassification that varies differentially by socioeconomic, household, or facility-level factors. However, as we employed a self-controlled case series design, non-time-varying socioeconomic factors are controlled by design, which would have greatly reduced the impact of this bias. In addition, climate exposures are influenced by many other factors including humidity and air quality, and additional analyses with more complex climate measurements are needed to expand on our findings. Our definition of heat-related hospitalization has been used in previous published studies but has not been validated in Medicare data; it likely captures only a subset of hospitalizations thought to result from heat effects, as the health effects of heat can also manifest as heart failure, syncope, shock or exacerbation of pre-existing conditions . In addiWhile extreme heat events are known to have dangerous consequences for human health, this study showed that even in the absence of extreme heat, many commonly-used potentially heat-sensitizing medications increase the rate of heat-related hospitalization during the warm summer months in older patients with chronic conditions. The observed effects of medications on heat-related events may become more problematic in light of increasing average summer and night-time temperatures . Older aS1 Fig(DOCX)Click here for additional data file.S1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S3 Table(DOCX)Click here for additional data file.S4 Table(DOCX)Click here for additional data file.S5 Table(DOCX)Click here for additional data file.


To the Editor;The novel coronavirus disease 2019 (COVID-19) is a global pandemic and threat all over the world. The first cases were seen in, Wuhan, China, in December 2019 , we preferred regional anesthesia over general anesthesia for these patients to reduce the need for airway manipulation. The blocks were performed in the operating room prepared for just COVID-19 or COVID-19-suspected patients. The drugs and equipment were all prepared in another clean room. Although neuraxial anesthesia and peripheral nerve blocks are not aerosol-generating procedures, we donned personal protective equipment, and the patients wore surgical masks. To minimize the need for conversion to general anesthesia, all the blocks were performed by the most experienced anesthetist.Written informed consent was obtained from the patients. According to practice recommendations on neuraxial anesthesia and peripheral nerve blocks during the COVID-19 by the American Society of Regional Anesthesia and Pain Medicine (ASRA) and European Society of Regional Anesthesia and Pain Therapy (ESRA) (The first case was a 38-year-old man who underwent wrist fracture operation. He had cough and sub-febrile fever (37.8 °C). After covering ultrasound transducer with plastic covers, ultrasound-guided infraclavicular block was performed.The second case was a 63-year-old man who underwent proximal femur fracture surgery. He had cough, fever (38.2 °C), and physical examination of bilateral crepitus at the base of the lungs. After ruling out thrombocytopenia, we performed spinal anesthesia at the level of L4–L5 intervertebral space.The third case was a 25-year-old cesarean section case. Her physical examination and vital signs were normal; however, her husband was COVID-19 positive. Her thrombocyte level was normal, and we performed her spinal anesthesia at the level of L3–L4 intervertebral space. The parturient had hypotension (75/50 mmHg) and recovered with 20 mg ephedrine. Because virus is isolated from cerebrospinal fluid (CSF), we did not allow the CSF to drip freely to reduce contamination in both of spinal anesthesia cases. Because continuous catheter techniques can increase the risk of frequent patient contact, we did not prefer epidural and perineural catheters.When it is thought that the transmission of this virus is via aerosols, dealing with these patients not only in intensive care units but also in the operating rooms puts the anesthetists in the most risk group about transmission. Therefore, any anesthesia technique that avoids the need for airway manipulations is crucial during this pandemic; in this situation, it is the regional anesthesia techniques such as central neuraxial blocks, peripheral nerve blocks, and interfascial plane blocks (Lie et al.


The novel COVID-19 infection has demonstrated a spectrum of complications involving vascular, inflammatory, infectious, and metabolic conditions. These complications range from mild loss of smell to more severe acute respiratory distress syndrome (ARDS). Patients with more severe complications often require sedation and mechanical ventilation. Growing research has revealed the role of active malignancy and disease-in-remission status as possible risk factors contributing to the morbidity and mortality in COVID-19 patients. In our descriptive case series, we present three unique cases of complicated COVID-19 infection in patients with hematologic-oncologic risk factors and review the imaging features of their complications. The first patient was a 33-year-old male with sickle cell trait who developed rhabdomyolysis and myonecrosis of the paraspinal muscle in the setting of a physical fitness test; he subsequently developed an abscess at this site, presumably exacerbated by the hypoxemic state of his COVID-19 pneumonia. Our second patient was a 37-year-old male with COVID-19 pneumonia and a history of stage IV Non-Hodgkin's lymphoma in remission who developed spontaneous pneumomediastinum in the absence of positive pressure ventilation. The third COVID-positive patient was a 54-year-old male with a past medical history significant for grade 1 follicular non-Hodgkin’s lymphoma in remission with sputum culture positive for mycobacterium avium complex and bronchoscopy positive for candida growth. 18-FDG/PET imaging was performed and demonstrated diffuse intense uptake throughout the lungs reflecting both the COVID-19 pneumonia and the multimicrobial superinfection. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belongs to an enveloped, non-segmented RNA virus in the beta-coronaviridae family. Also known by its clinical infection name of COVID-19, it has resulted in significant morbidity and mortality primarily in patients with comorbidities. Described complications include super-infection from viral, bacterial, fungal etiologies, myocarditis, encephalopathy, as well as liver and kidney injury. Recent studies have investigated outcomes in COVID-19 patients with active hematologic malignancy, with evidence of worse outcomes in this cohort . The potCase 1A 33-year-old male soldier with sickle cell trait was admitted due to rhabdomyolysis complicated by COVID-19 positivity. The patient developed rhabdomyolysis after collapsing on a run, and was noted to have a creatine kinase of greater than 100,000 U/L on admission. This presentation was attributed to possible exercise-collapse associated with sickle cell trait (ECAST) complicated by PCR confirmed COVID-19 positivity. His hospital course was complicated by acute renal failure requiring hemodialysis, methicillin-sensitive staph aureus pneumonia, and a pulmonary abscess. During his hospital course, the patient developed back pain and was noted to have hemorrhage into his lumbosacral musculature secondary to rhabdomyolysis induced myonecrosis Figure , d. The Case 2A 37-year-old male with a past medical history significant for stage 4 Non-Hodgkin's lymphoma in remission and hemophagocytic lymphohistiocytosis (HLH) was admitted for COVID pneumonia in the setting of neutropenic fever. The patient had a total of four admissions during which he was managed with various antimicrobial, antiviral, and antifungal pharmacotherapy given his neutropenic state. His third admission was complicated by shortness of breath secondary to segmental and subsegmental pulmonary emboli, which were treated with a heparin drip while transitioning to apixaban. By his fourth admission, the patient presented to the emergency room for a one-day history of chest pain that radiated to his neck. The patient endorsed difficulty with swallowing and subjective changes to his voice. He also complained of shortness of breath and diffuse arthralgias. A CT neck and chest was performed which demonstrated pneumomediastinum without evidence of pneumothorax Figure . The patCase 3A 54-year-old male with a past medical history significant for hepatitis B, cirrhosis, psoriasis, and grade 1 follicular non-Hodgkin’s lymphoma in remission who was admitted multiple times for respiratory failure in the setting of COVID-19 pneumonia. The patient’s third admission was complicated by acute hypoxic respiratory failure, intubation, and acute kidney injury. Extensive lab work was negative for additional superinfection, including histoplasmosis, cryptococcus, coccidioides, aspergillus, and CMV. Initial bronchoscopy resulted in unsatisfactory samples for evaluation and initial blood cultures were negative. Due to the patient’s multiple admissions, oncologic history, and extended hospital course without improvement, F-18 FDG/PET study was performed to evaluate for occult infection. This revealed intense radiotracer uptake within the lungs as well as within mediastinal and hilar lymph nodes Figure . There wThe SARS-CoV-2 represents the leading cause of morbidity and mortality in patients infected with COVID-19. Patients with SARS-CoV-2 often experience a variety of pulmonary and extrapulmonary complications and often require intubation and supportive care. Various studies have demonstrated worse outcomes in COVID-19 patients with active hematologic malignancy as well as those in remission. Hospitalized patients with hematologic malignancy, such as lymphoma, had a more severe course and a higher fatality rate . These cSickle cell trait represents the carrier state of an autosomal recessive genetic disorder. As a heterozygous state, sickle cell trait patients have one copy of mutant Hb (HbS) and one copy of a wild type allele Hb (HbA). This mutation results from a missense mutation where glutamic acid is replaced by valine in the 6th codon of the β-globulin chain. The presence of a normal allele in this recessive condition prevents the formation of polymers, and the vast majority of patients are asymptomatic. Increased oxygen demand, however, has been shown to trigger various complications in patients with sickle cell trait . The rolOur second patient demonstrated a case of spontaneous pneumomediastinum, another unusual complication of COVID-19. There has been a growing number of case reports of spontaneous pneumomediastinum associated with COVID-19 pneumonia with the exact mechanism not well understood . IncreasCOVID-19 cases with 18F-FDG PET imaging have been a source of growing interest especially in patients with active malignancy. One of the earliest descriptions of 18F-FDG PET/CT findings in COVID-19 demonstrated a mass-like accumulation of FDG with lymphadenopathy . An earlUnfortunately, the use of PET/CT in the setting of COVID-19 has been limited due to the length of time 18F-FDG PET/CT procedures take to perform and the associated risks of prolonged scan time and of spreading infection in the nuclear medicine department. The implementation of aggressive disinfecting protocols and expedited PET examinations could be considered to enable PET workups in COVID-19 patients [In addition to the utility of PET/CT patterns in evaluating known COVID-19 patients, it is important to note that many case reports have demonstrated the incidental detection of COVID-19 pneumonia in asymptomatic carriers both with and without malignancy. In fact, between 40% and 45% of patients with COVID-19 may be asymptomatic [Growing research into the novel COVID-19 epidemic has shown a wide range of pulmonary and extrapulmonary complications secondary to this viral illness. Various risk factors, including active and prior malignancy, have demonstrated their importance in predicting outcomes for COVID-19 patients. Additional associations of COVID-19 with pneumothorax and pneumomediastinum are important considerations and have been suggested to have prognostic significance. The exact role of 18F-FDG PET/CT in the evaluation of patients infected with COVID-19 is evolving and may have a limited utility in certain cases. While increased morbidity and mortality in patients with sickle cell disease has been well established, more research into the role of morbidity associated with sickle cell trait is warranted, especially in light of the severe complications suffered by the first patient in our series.


The use of an electronic hand hygiene monitoring system (EHHMS) decreased due to the coronavirus disease 2019 (COVID-19) pandemic. We analyzed dispenser use, hand hygiene (HH) badge use, and HH compliance to determine the effect of COVID-19 on EHHMS use and HH compliance. HH product shortages and other pandemic-induced challenges influenced EHHMS use. The technology uses personally identifiable badges worn by healthcare workers. Each badge records individual HH events through a wireless connection with sensors in soap and alcohol-based product dispensers. Beacons attached to patient beds monitor HH compliance before and after patient care. Dispenser use by badged and unbadged staff, patients, and visitors was recorded.The distribution of badges to staff is underway in a phased implementation; units and provider groups have been assigned to 1 of 5 waves. The first implementation wave took place in May 2019 (9 units), the second in October 2019 (7 units), and the third in January 2020 (6 units). The pandemic interrupted plans to implement waves 4 and 5 in April and July, respectively. COVID-19 patients were primarily housed on 3 units within the hospital: a progressive care unit, an acute-care unit, and the medical respiratory intensive care unit (MRICU). The progressive care unit was issued badges in wave 1. The acute-care unit and the MRICU received badges in wave 2.7 Their work continued uninterrupted by the COVID-19 pandemic.In addition to the EHHMS, HH observers make rounds on units to monitor HH compliance. Trained observers assess HH compliance in a standardized manner, as previously described.The pandemic caused increased demand for sanitizer resulting in HH product shortages. We began allocating our HH product in February 2020 and subsequently rationed the wall-dispenser sanitizer at the beginning of March 2020. When a unit ran out of sanitizer in a wall dispenser, they were supplied with pump-bottle sanitizers or flip-top bottles. The wall dispenser was unavailable for a short period starting April 18, 2020. During this period, each unit was supplied with a maximum of 2 pump bottles of sanitizer per day. On April 28, 2020, we began reusing and refilling wall-sanitizer bottles with an alternate sanitizer product.2 tests using Excel .The first COVID-19 patient under investigation (PUI) was seen in our hospital on March 2, 2020. For the purposes of this study, we consider November 2019 to February 2020 our pre–COVID-19 period and March 2020 to June 2020 our post–COVID-19 period. COVID-19 volume in the hospital is expressed as COVID-19 patient days of all patient days for the following months: March , April , May , and June . The COVID-19–positive patient rooms required distinct procedures for entering and exiting with PPE. However, badges (including ID and HH badges) were worn under the PPE throughout the patient care episode, such that no specific treatment was required for badges after doffing PPE unless a breach occurred. To better understand the trends in use of the EHHMS and to identify barriers to use, we analyzed monthly HH data from both the observers and the EHHMS. Variables of interest included compliance through the EHHMS and direct observation, HH product use through the EHHMS, badge use by providers, and location (COVID-19 unit vs non–COVID-19 unit). Pre– and post–COVID-19 data were compared, as was practice on COVID-19 units versus non–COVID-19 units. Compliance data were analyzed using χDispenser use reached a peak in March with a 17% increase from November from 2,058,977 to 2,403,199 dispensing events Fig. . DispensBefore the COVID-19 pandemic, an average of 453 wave 1 and 2 employees used their badges per day. After the COVID-19 pandemic, the average number declined by 44% (427 in February to 240 in June). On COVID-19 units, the average daily number of nursing staff using their badges went from 64 in February to 21 in June, a 67% decline in use Fig. . Wave 3 P < .0001) and 6% hospital-wide when comparing pre– versus post–COVID-19 data (P < .0001). The EHHMS data showed an increase in compliance of 1% on both COVID-19 units (P = .0002) and hospital-wide (P < .0001) when comparing pre– versus post–COVID-19 data (Table Direct observation data indicated an increase in compliance of 10% on COVID-19 units (The COVID-19 pandemic presented new barriers to HH compliance and the use of an EHHMS. Lack of access to wall sanitizer may have affected healthcare workers ability to use foam on entry and exit using the technology. Use of badges decreased due to perceived inconvenience and incompatibility with donning and doffing procedures for COVID-19 patient rooms. Staff expressed concerns about potentially contaminating items taken into rooms and the time-consuming nature of cleaning the badge after leaving each COVID-19 room. Suboptimal messaging regarding badge best practices played a significant role in the decrease of badge use throughout the hospital. Badge users also reported a perception that the EHHMS was no longer necessary or accurate given the introduction of alternate products during allocation and shortages of wall sanitizer. Due to the constant changes in the environment during the pandemic, monthly compliance reports were not distributed.8 This finding suggests more events by bedside staff during this time period whether or not they were badged. The decrease in opportunities for HH measured by both observers and the EHHMS is likely the result of a lower overall census and limitations on room entries during the COVID-19 pandemic.Nevertheless, overall HH compliance by direct observation increased during the COVID-19 pandemic, particularly on COVID-19 patient units. An overall increase in HH despite declining usership of EHHMS badges is indicated by the dispensing events recorded by the EHHMS. The number of dispensing events increased in March, followed by relative stability in April and May despite a lack of visitors in the environment using the dispensers, similar to that reported by Moore et al.HH is recognized as important by healthcare providers during the COVID-19 pandemic, particularly on high-risk units. However, barriers to badge use may prevent participation in the EHHMS, which has the ability to provide an extra layer of safety in the form of end-user reminders. Confusion around management of the badge when entering and exiting rooms highlights a need to address other items such as ID badges and cell phones in PPE procedures such that providers understand best practices for protecting these items from contamination and disinfecting them routinely. Product shortages are disruptive when an infection prevention program is working to optimize infection prevention initiatives. Significant efforts will need to be directed toward re-establishing the EHHMS as an integral component of the organizational safety mission.