Background: The World Health Organization declared the coronavirus disease-2019 (COVID-19) a pandemic in December 2019. COVID-19 can affect most organs of the body but predominantly affects the lungs. Chest infection is associated with hyponatremia primarily due to inappropriate ectopic secretion of antidiuretic hormone. We conducted a six-month retrospective observational study to evaluate the relationship between chest X-ray (CXR) radiological findings and serum sodium levels. Our secondary goal was to assess the relationship between CXR findings and patient outcomes.Aim of the Study: To assess the relationship between the initial CXR findings, hyponatremia severity, and outcome in COVID-19 infected patients.p-value ≤  0.05 was considered significant.Materials and methods: We conducted a retrospective review of CXR findings of COVID-19 patients aged > 18 years. The patients were healthy and had no history of hyponatremia before COVID-19 infection. All recruited patients were admitted to one of four hospitals in Qatar  between March and June 2020. We excluded patients with factors that contributed to hyponatremia. Three score grades were established to describe the CXR findings. Patients were divided into three groups by the principal researcher according to their serum sodium levels. A radiologist evaluated the CXR findings with the patient and group information obscured. The principal researcher collected the X-ray scores for analysis with the serum sodium levels. We used SPSS for Windows, Version 15.0.  and STATA Package Version 12.0  to analyze the data. A p < 0.001). More than 95% of the patients who developed hyponatremia were >30 years. Moderate and severe hyponatremia was more prevalent in patients with Grade 1 or Grade 2 CXR findings and were >30 years.Results: A total of 414 CXR patients with COVID-19 were recruited; 275 patients had hyponatremia and 139 had normal sodium levels and were used as the control group. Patients with normal serum sodium and hyponatremia were classified into three categories based on the CXR findings. Grade 0 (95), Grade 1 (43), and Grade 2 (137) hyponatremic patients were reported. The mean sodium levels were 133.6, 131.3, and 127.2 mmol/L for Grades 0, 1, and 2, respectively (Conclusion: Serum sodium levels in COVID-19 patients correlated well with the severity of the CXR findings observed at the early disease stage. Furthermore, simple CXR scores can be used to identify COVID-19 patients at a higher risk of hyponatremia, length of hospital stay, medical care support type, and mortality. Patients with COVID-19 may be asymptomatic, although mild upper respiratory tract infections or severe pneumonia can develop, leading to acute respiratory distress syndrome (ARDS), shock, and multiorgan failure. Extensive research has identified several risk factors that increase the susceptibility for developing severe illness; namely, older age, diabetes, chronic kidney disease, obesity, and chronic cardiovascular disease. There is great clinical benefit in establishing clinical and laboratory parameters that can help identify patients at risk of developing a long course of the disease, perform timely interventions, and identify novel therapeutic modalities to treat COVID-19 infection.The coronavirus disease-2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome due to Coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has ravaged the world since December 2019, disrupting the global economy and healthcare systems. The number of worldwide COVID-19 cases reached 501,970,999 on April 14, 2022, of whom 6,190,360 died. Hyponatremia is one of the most common electrolyte abnormalities in patients with SARS-CoV-2 infection. Hyponatremia has been linked to an increase in the release of antidiuretic hormone (ADH) from hypothalamo-hypophyseal axis stimulation due to illness and stress, pneumonia-induced lung injury, direct/indirect renal injury, or a cytokine storm. Increased ADH secretion causes a syndrome of inappropriate antidiuretic hormone secretion (SIADH).Recent studies have shown that the virus gains access to the host cells, particularly the lungs, via the angiotensin-converting enzyme-2 (ACE-2) receptor, introducing various degrees of tissue damage. It has been postulated that a low serum sodium level may lead to an upregulation of ACE-2 receptors, thereby inviting a more significant load of viral particles culminating in increased disease severity. CT findings have a sensitivity of up to 90% and have been promoted as the first-line imaging modality for diagnosis in different countries. Nevertheless, CXR may have a role in diagnosing and evaluating the progression of lung involvement, particularly in the intensive care setting. A chest CT scan standardized scoring system, known as the COVID-19 Reporting and Data System (CO-RADS), is currently available and widely used. Although experimental CXR scoring systems have been proposed, none have been validated for a SARS-CoV-2 chest infection. Hui et al. concluded that the degree of CXR changes correlates more with the severity of SARS-CoV-2 chest infection than with laboratory markers. The same study showed that normal or very mild changes are associated with a more stable disease course, although CXRs were done 6–10 days after symptom onset. Scoring systems for ARDS, such as the radiographic assessment of lung edema (RALE) score are well known and have been used to evaluate the severity of pneumonia and the risk of intensive care unit (ICU) admission. Wong et al. used the RALE score to assess the time course and severity of CXR changes in patients with SARS-CoV-2 and reported significant bilateral lower zone consolidation 10–12 days after symptom onset with a sensitivity of 69%. Another scoring system described by Taylor et al. is used to assess the degree of severe acute respiratory infection by non-radiologists. This score has five categories according to the severity of the CXR findings: 1 – normal; 2 – patchy atelectasis and/or hyperinflation and/or bronchial wall thickening; 3 – focal consolidation; 4 – multifocal consolidation, and 5 – diffuse alveolar changes. Only one study has assessed this scoring system in patients with SARS-CoV-2 infection; however, the correlation between severity and the radiographic findings was poor. Borghesi et al. recently described a scoring system (the Brixia score) for SARS-CoV-2 infection based on dividing the CXR into six zones, scoring each zone based on the presence of infiltrates and combining the scores into one definitive score ranging from 0 to 18. They showed that a higher score was associated with increased mortality; however, this score must be validated by other studies. CXR is more readily available than CT; it is a cost-effective tool when used appropriately, particularly in overburdened healthcare systems. This study correlated the earliest CXR findings in both lungs of COVID-19 pneumonia patients with serum sodium levels and their likely outcomes.Chest X-ray (CXR) is not a sensitive method to detect lung changes in viral pneumonia at its early stages, whereas chest computed tomography (CT) imaging has been proven to be a reliable diagnostic tool for assessing lung involvement and severity during the early stages of a COVID-19 infection.Ethics Committee approval was obtained from the Medical Research Centre (MRC) (Number: MRC-05-211) for this retrospective observational study. COVID-19 pandemic management in Qatar is coordinated by the Hamad Medical Corporation, which is under the purview of the Ministry of Public Health. At the beginning of the pandemic, four main hospitals were designated as COVID-19 treatment facilities . We reviewed the clinical and imaging records of all COVID-19 pneumonia patients aged >18 years with polymerase chain reaction-confirmed SARS-CoV-2 infection who were admitted to any of these facilities between March and June 2020. The exclusion criteria eliminated any other contributing factors for hyponatremia, including chronic SIADH, diarrhea, hyperlipidemia, chronic low serum sodium, chronic kidney disease, an endocrine disorder, diabetes, hypertension, cardiovascular disease, and other known diseases that may cause hyponatremia or affect the outcome of COVID-19 infection. These guidelines proposed hyponatremia ranges of low (130–135 mmol/L), moderate (125–129 mmol/L), and severe ( < 125 mmol/L). The CXR findings used to describe the grades were discussed thoroughly among the team members, including the radiology consultant. A simple scoring system was proposed to describe the initial CXR findings. The CXR findings were scored as follows: Grade 0 indicated the CXR had unremarkable findings  (The hyponatremic patients were divided into three subgroups according to their serum sodium levels. The severity of the hyponatremia was classified according to the Joint European guidelines. fields) ; Grade 1 fields) , and Gra fields) . PatientU-test or t-test was performed for two groups according to the distribution or homogeneity of the continuous variables. Categorical variables are reported as frequencies and percentages. Nominal and categorical variables were compared using the chi-square test and Fisher's exact test, respectively. The association between serum sodium levels and outcomes was assessed by univariate analysis. Logistic regression analysis with stepwise backward elimination was performed to confirm the risk factors of hyponatremia at diagnosis in patients with COVID-19. The means of the parameters between the three CXR groups were compared using analysis of variance (ANOVA) for normally distributed variables and the Kruskal-Wallis test for non-normally distributed variables. Missing data were handled primarily by complete case analysis at the time of the statistical analysis. As a secondary analysis, missing data were imputed using multiple imputations. A p-value ≤ 0.05 was considered significant.We used SPSS for Windows, version 15.0.  and STATA Package version 12.0  for the exploratory data analysis and descriptive statistics, respectively. The Mann-Whitney In total, 469 admitted patients with COVID-19 pneumonia were identified in the four qualifying hospitals in Qatar between 1 March 2020 and 30 June 2020. Three patients were excluded due to the lack of X-ray images, and 52 patients were excluded due to the aforementioned hyponatremia contributing factors; thus, 414 patients were enrolled in this study . Most pap < 0.001). The mean sodium level in Grade 0 patients was 133.6 ± 6.8 mmol/L, 131.3 ± 6 mmol/L in Grade 1, and 127.2 ± 5.8 mmol/L in Grade 2 . Unexpectedly, serum potassium, creatinine, hemoglobin (Hgb), and white blood cell (WBC) levels were within the normal ranges in hyponatremic patients. A multivariate logistic regression adjusted for age, serum creatinine, serum potassium, WBCs, hemoglobin, and platelet count was conducted to assess their effect on the relationship between the CXR grade and serum sodium. The changes in the platelet count were significantly associated with the CXR findings and serum sodium levels stratified by illness severity among patients with SARS-CoV-2 infection.The statistical analysis revealed a negative correlation between the X-ray grade and serum sodium concentration . The WBC count was within the normal range in the two groups; however, it tended to be higher in the hyponatremic patients who had Grade 1 and Grade 2 X-ray findings   .Fifteen patients (8%) died in the hyponatremia group: two had Grade 1 CXR findings and 13 patients had Grade 2 CXR findings. Three of the 15 patients in the medical ward died unexpectedly, and only one patient of the three received ventilator support during resuscitation. The other 12 patients were admitted to the ICU. Eleven patients developed severe desaturation and required mechanical ventilatory support, whereas the other died without ventilator support. The average lengths of stay were 17 and 29 days in the medical ward and ICU, respectively. The cause of death was septic shock in nine patients, and seven of these nine patients developed ARDS. The other six patients died possibly due to pulmonary embolism and acute kidney injury or cardiac complications, such as carditis or arrhythmias. Nearly 60% of patients reported low sodium levels in a study from Hong Kong. Similarly, hyponatremia is one of the most common electrolyte abnormalities in patients with SARS-CoV-2 infection. The pathogenesis of hyponatremia in patients with COVID-19 infection is uncertain; however, low serum sodium during a COVID-19 infection seems to be primarily due to an inappropriate increase in ADH secretion. Higher ADH secretion appears to occur because of abnormalities in the hypothalamo-hypophyseal axis. These abnormalities could be due to inflammation of these glands by the SARS-CoV-2 infection. Contributory factors, such as disease stress, inflammatory lung injury, and a cytokine storm can contribute to hyponatremia. Another possible mechanism of low serum sodium in patients with COVID-19 is linked to the deposition of virus particles in the glomeruli and tubules, which directly damage these structures. Furthermore, COVID-19 infection causes acute proximal tubular injury associated with glomerular thrombi due to direct glomeruli endothelial damage. These abnormalities in the nephrons may cause a defect in sodium handling, resulting in hyponatremia.Interestingly, hyponatremia was reported as one of the most common electrolyte abnormalities during the SARS pandemic in 2003. However, other mechanisms of hyponatremia are being investigated.Pneumonia is a well known cause of SIADH and could be an inciting factor for hyponatremia in patients infected with SARS-CoV-2. This process is mediated via the ACE-2 receptor, which facilitates the entry of viral particles into cells, resulting in damage, acute kidney injury, and electrolyte abnormalities. These receptors are present in the lungs, heart, muscle, bowel, and kidneys, which explains the increased susceptibility of those organs to SARS-CoV-2-related injury. This process is compounded by a cytokine storm, with increased levels of interleukin (IL)-6, which cause glomerular damage and tubular necrosis.Direct renal injury by SARS-CoV-2 has occurred in the proximal convoluted tubules via viral particles.The present study results reveal a significant association between COVID-19 pneumonic CXR findings and serum sodium concentration. According to the CXR score used in the present study, infection severity was negatively correlated with the sodium level . CO-RADS is an established grading system for COVID-19 pneumonia based on CXR findings. However, given the high cost and limited availability of CT machines even at leading hospitals, and the large influx of COVID-19 patients, CT was not an appropriate tool for wide use during the pandemic in new hospitals that were not well equipped. However, CXR machines are widely available in most centers and are relatively more accessible, and X-rays are less expensive and easier to perform than CT scans. Unfortunately, X-rays have no validated scoring system (such as CO-RADS for CT scans), making X-ray findings alone a less objective tool to assess COVID-19 severity, particularly during the early stage of COVID-19 pneumonia. Several scores have been described for ARDS, such as the score described by Borghesi et al. for SARS-CoV-2 infection . This score divides the CXR into six zones, and each zone is scored based on the presence of infiltrates; the combined score ranges from 0 to 18. CXR findings in our study were classified according to the severity and the extension of CXR observations into three grades. We detected a negative correlation between the grade of the CXR findings and serum sodium level  improve hyponatremia and reduce the risk of death. Despite that IL-6 was not measured (a limitation of retrospective studies), it was likely very high and may have played a role in developing hyponatremia and pneumonia severity at least in some of our patients.A direct relationship has been reported between the severity of COVID-19 pneumonia and IL-6 serum levels. Low serum potassium in COVID-19 patients was also reported by Alfano et al. We found a significant association between the severity of COVID-19 and potassium levels, as nearly 86% of patients had serum potassium levels within the lowest normal of the reference range; however, this did not correlate significantly with pneumonia grade. Hypokalemia is a common electrolyte disturbance in patients with COVID-19, particularly in patients undergoing diuretic therapy. In the present study, serum potassium was at the lower end of the normal range, particularly on Grade 0 CXR findings although there was no statistical significance . Given the nature of the study, we could not validate the scoring system with the patients’ clinical condition at that time or with the CT scoring system because most of our patients had not had a chest CT. The study would have benefited from patients having had chest CT scans at the same time as the X-ray, which would allow a comparison between our scoring system and CO-RADS. The CXR used in this study was the first CXR done at presentation, unlike other studies that used a CXR performed later (6–10 days after presentation), making our scoring system validation inappropriate according to previous scoring systems. The use of the first CXR, which was done at presentation, may explain the minor CXR findings reported in this study. However, a significant correlation was observed between hyponatremia, the hematological changes, and outcome. Serum IL and vasopressin hormone levels were not measured because it was a retrospective study. Nevertheless, an association between the severity of hyponatremia, pneumonia, outcomes, and the CXR findings was detected. The other limitation is the higher number of male patients, which may be due to the male predominance in the Qatar population .Serum sodium concentration was strongly correlated with the severity of CXR findings during the early stages of COVID-19 pneumonia. Although the CXR score used in this study was not validated, it appears to be a reasonable scoring method to predict hyponatremia severity, hospital stay, level of medical support required, and mortality in patients with COVID-19 pneumonia. However, further research is required to validate this scoring system and compare it with CT-CORAD and other scoring systems. Therefore, we urge clinicians and researchers to try the CXR scoring system described in this study, particularly in low-income countries, because CXR is less expensive, more widely available, and faster to perform than a CT scan.Habas E and Ahmed FR initiated the study by writing the approval protocol. These two authors were the principal manuscript editors, sharing equally. Said A graded the X-rays and reported all X-rays findings as grades. Ghazouani H performed all statistical analyses and generated the tables and figures. The other authors helped with data collection, processing, and revising the manuscript.Conflict of Interest: None of the authors has a conflict of interest to declare.Financial Support: HMC Research Center financially supported the publication fees for the study.


Breast cancer in young women under 40 years of age shows a poor prognosis, and its treatment is difficult due to premenopausal status and fertility preservation. The early prediction of prognosis of young age breast cancer would be helpful for planning treatment and postoperative surveillance. In this study, the radiomics-based nomogram for the prediction of recurrence shows good predictive ability, especially 2-year disease-free survival after surgery. Several radiomics features presumed to be unique imaging features of young age breast cancer were also observed: tumor homogeneity and tumor sphericity. As these radiomics features are quantitative parameters extracted through the texture analysis of breast MRI, they may reflect the information of tumors more objectively, such as the tumor microenvironment. Furthermore, these results will be the basis for identifying the unique biology of young age breast cancer through multi-omics studies such as radio-genomics.p = 0.003) and validation set (p = 0.020) in the Kaplan–Meier analysis. The nomogram was generated through Cox proportional hazards models, and its predictive ability was validated. The nomogram included the Rad-score and estrogen receptor negativity as predictive factors and showed fair DFS predictive ability in both the training and validation sets . In conclusion, the Rad-score can predict the disease recurrence of invasive breast cancer in women under 40 years of age, and the Rad-score-based nomogram showed reasonably high DFS predictive ability, especially within 2 years of surgery.This study aimed to predict early breast cancer recurrence in women under 40 years of age using radiomics signature and clinicopathological information. We retrospectively investigated 155 patients under 40 years of age with invasive breast cancer who underwent MRI and surgery. Through stratified random sampling, 111 patients were assigned as the training set, and 44 were assigned as the validation set. Recurrence-associated factors were investigated based on recurrence within 5 years during the total follow-up period. A Rad-score was generated through texture analysis  of breast MRI using the least absolute shrinkage and selection operator Cox regression model. The Rad-score showed a significant association with disease-free survival (DFS) in the training set ( For decades, the development of treatment and screening systems for breast cancer has contributed to improving breast cancer mortality rates ,2,3. DesStandard screening programs and treatment guidelines for breast cancer are currently based on the data of breast cancer patients of average age, especially in the Western hemisphere. In addition, regardless of the continent, most of the previous studies evaluated breast cancer in average-age women. With the recent increase in the incidence of breast cancer in Asia, several clinical studies have investigated the characteristics of YABC. However, most studies have focused on the treatment methods or molecular characteristics of Asian YABC ,13, and Considering this background, we aimed to utilize the recurrence-associated imaging features to create the radiomics signature of YABC and establish a nomogram for the prediction of disease-free survival (DFS) of YABC using radiomics signature and variable clinical factors.This retrospective study was approved by the Institutional Review Board of our institution. The requirement for informed consent was waived by the ethics committee due to the retrospective design. All assessments were carried out according to the Declaration of Helsinki of 1975, revised in 2013.n = 21) or patients with incomplete MR data (n = 86) were excluded. To investigate the DFS rates two years after surgery, patients with less than two years of follow-up (n = 58) were excluded. Patients who had not been diagnosed with recurrent breast cancer by the end of five years were censored.From January 2011 to February 2019, among 4451 patients who underwent breast cancer surgery in our institution, 320 female patients under 40 years old who were diagnosed with invasive breast cancer were consecutively included. Because pretreatment breast MRI was used to create the radiomics signature, patients without pretreatment MRI  was performed. The detail of each sequence is described in https://slicer.org/, accessed on 1 June 2020) in the early phase of contrast-enhanced T1-weighted subtraction imaging and ADC mapping. If the target lesion was not clearly delineated on the ADC map, the segmented volume of interest on early-phase contrast-enhanced T1 subtraction images was applied to the ADC map with modification. After the segmentation of the target lesion, radiomics features were extracted using open-source PyRadiomics software. A total of 107 features were extracted from early-phase contrast-enhanced T1 subtraction images and ADC maps.Two expert breast radiologists with 8 and 24 years of experience in breast MRI retrospectively reviewed the pretreatment breast MRI using a picture archiving and communication system (PACS) with a workstation monitor. The target lesion was defined as the largest enhancing lesion regardless of mass or non-mass enhancement. One radiologist segmented the target lesion three-dimensionally with a semiautomatic tool using an open-source software package . We fitted the least absolute shrinkage and selection operator (LASSO) Cox regression model using the “glmnet” package, and the “rms” and “hdnom” packages were used for the Kaplan–Meier curve, nomogram and calibration plot.As in the standard statistical inference, two-tailed n = 111) and a validation set (n = 44) to create a radiomics signature (Rad-score). To compare patients’ characteristics between the two cohorts, we conducted a Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables. We first used the univariate Cox proportional hazards model to screen for insignificant variables. We then used the LASSO regularization method [We randomly divided patients into a training set , 42 patients were diagnosed as experiencing recurrence. Among the 42 recurrent patients, 3 were diagnosed as experiencing recurrence after five years (60 months) of surgery and were censored. Among the 39 recurrent patients, 20  experienced disease recurrence within 24 months, with a median recurrence interval of 13 months . Of the 20 cases of recurrence, 13 were manifested as local recurrence of the ipsilateral breast, 6 were manifested as distant metastases to the lung, brain and contralateral supraclavicular lymph nodes, 1 was manifested as contralateral breast recurrence, 1 was manifested as both ipsilateral breast recurrence and distant metastasis, and 1 was manifested as both contralateral breast recurrence and distant metastasis. The patients’ characteristics in each cohort are listed in The 214 total texture features (107 from each cohort), including shape (14 features), first-order (18 features), gray-level co-occurrence matrix (24 features), gray-level run-length matrix (16 features), gray-level size zone matrix (16 features), gray-level dependence matrix (14 features) and neighboring gray-tone difference matrix (5 features), were extracted. These features were standardized and used to generate the radiomics-based scoring equation (Rad-score). Based on the fitted LASSO Cox regression model from the training set, the Rad-score for predicting disease recurrence was created as follows:Using the equation above, the Rad-score of each patient was calculated, and the patients in the training set were classified as high- or low-risk for disease recurrence. The optimal cut-off value for separating the high- and low-risk patients was determined to be −0.016 according to Youden’s index. The characteristics of the patients according to risk are presented in p = 0.003). Similarly, the high-risk group showed significantly lower survival rates in the validation set (p = 0.020)  .p < 0.001) and ER-negativity (p = 0.044) were associated with recurrence. Multivariate analysis confirmed the independent association of Rad-score  and ER-negativity  with disease recurrence , displaying fair predictive ability for disease recurrence, whereas the C-index of the ER-negativity-only model was 0.51 (95% CI 0.39–0.66). In addition, the Rad-score-only model showed a value of 0.71 (95% CI 0.51–0.86). The calibration curves of these models in the validation set are shown in In this study, we developed a radiomics-based nomogram for predicting early disease recurrence in YABC. Rad-score and ER negativity were associated with early cancer recurrence within two years of surgery. Among the three prediction models, those employing the Rad-score demonstrated higher predictive ability for recurrence than the model that only included ER status. Moreover, the Rad-score-only model showed a higher predictive performance than the Rad-score and ER negativity model. Note that the relatively small sample size may lead to larger variability in predictive ability; the sparse model is often preferred in this case. However, as we pointed out, the sample size used in this study can still provide a small margin of error close to the threshold value suggested in .The Rad-score was generated using the equation created from six features of the tumor texture analysis. Of these six features, a few were consistent with a previous study on YABC. Previously, a low surface-area-to-volume ratio, indicating tumor sphericity, and texture parameters indicating tumor homogeneity exhibited an association with cancer recurrence . In thisGenerally, tumor heterogeneity from texture analysis is a poor prognostic factor, as it represents aggressive tumor biology ,29. HoweOf the 20 cases of disease recurrence, 10 showed ER-negativity, 2 of which were HER2 positive and 8 were triple-negative. Because we investigated DFS within two years of surgery, the high proportion of the triple-negative subtype is expected due to the aggressive nature of the triple-negative subtype ,34. In oThis study has the limitation of the inevitable selection bias of YABC cases because it was a retrospective study conducted at a single institution. Second, a relatively small sample size was used to make and validate the nomogram. Moreover, the Rad-score-only model showed a higher predictive performance than the radiomics nomogram model, which has both the Rad-score and ER negativity as predictors. Note that the relatively small sample size may lead to a larger variability in prediction; in this case, the model with a smaller number of predictors is often preferred in the test dataset. Therefore, we calculate a margin of error and compare it with the guidelines provided in . For a gIn conclusion, our nomogram based on the radiomics signature and clinicopathologic information showed reasonably high predictive ability of disease-free survival, especially within 2 years of surgery. Future prospective studies should be conducted to validate the predictability of the radiomics nomogram for YABC. Furthermore, it is crucial to determine the relationship between tumor biology including genetic mutation and the imaging phenotype of YABC through multi-omics studies.


Back pain is an extensive burden to our healthcare system, yet few studies have explored modifiable prognostic factors associated with high costs related to healthcare utilization, especially among older back pain patients. The aims of this study were to identify modifiable prognostic factors for high costs related to healthcare utilization among older people seeking primary care with a new episode of back pain; and to replicate the identified associations in a similar cohort, in a different country.Data from two cohort studies within the BACE consortium were used, including 452 and 675 people aged ≥55 years seeking primary care with a new episode of back pain. High costs were defined as costs in the top 25th percentile. Healthcare utilization was self-reported, aggregated for one-year of follow-up and included: primary care consultations, medications, examinations, hospitalization, rehabilitation stay and operations. Costs were estimated based on unit costs collected from national pricelists. Nine potential modifiable prognostic factors were selected based on previous literature. Univariable and multivariable binary logistic regression models were used to identify and replicate associations (crude and adjusted for selected covariates) between each modifiable prognostic factor and high costs related to healthcare utilization.Four modifiable prognostic factors associated with high costs related to healthcare utilization were identified and replicated: a higher degree of pain severity, disability, depression, and a lower degree of physical health-related quality of life. Kinesiophobia and recovery expectations showed no prognostic value. There were inconsistent results across the two cohorts with regards to comorbidity, radiating pain below the knee and mental health-related quality of life.The factors identified in this study may be future targets for intervention with the potential to reduce high costs related to healthcare utilization among older back pain patients.ClinicalTrials.gov NCT04261309, 07 February 2020. Retrospectively registered.The online version contains supplementary material available at 10.1186/s12913-022-08180-2. The burden of back pain has been growing along with an increasing and ageing population –5. Back To improve use of scarce healthcare resources and reduce the burden on our healthcare systems, where possible and appropriate, researchers have highlighted the importance of monitoring and understanding healthcare utilization and related costs , 11. It Only a few prospective studies have explored modifiable prognostic factors associated with high costs related to healthcare utilization among patients with back pain –17, and Therefore, the aims of this study were 1) to identify modifiable prognostic factors for high costs related to healthcare utilization among older people seeking primary care with a new episode of back pain and 2) to replicate the identified associations in a similar cohort, in a different country.ClinicalTrials.gov NCT04261309, 07 February 2020) including a statistical analysis plan has been published [This study was designed and performed in accordance with the PROGnosis RESearch Strategy (PROGRESS) framework , with aiublished , and theublished .This study was carried out in two steps. First, modifiable prognostic factors were identified in the Back Complaints in the Elderly - Norway study (BACE-N), a prospective observational cohort study within Norwegian primary care . Next, aEligible participants within BACE-N were people ≥55 years of age seeking primary care ) with a new episode of back pain (preceded by 6 months without visiting primary care for similar complaints). Eligible participants within BACE-D were people > 55 years of age seeking primary care (GP) with a new episode of back pain (preceded by 6 months without visiting a GP for similar complaints). Patients were excluded from both studies if they had difficulties completing the questionnaires due to language barriers, or if they had difficulties completing the physical examination (e.g. are wheelchair bound). Patients within BACE-N were recruited by 110 physiotherapists, chiropractors and GPs in urban and rural parts of Norway between April 2015 and February 2020. Patients within BACE-D were recruited by 49 GPs in and around Rotterdam between March 2009 and September 2011. All included patients signed an informed consent form before study enrolment.At baseline all patients responded to a comprehensive questionnaire and went through a standardized physical examination. Follow-up questionnaires were sent at 3, 6, and 12 months after inclusion within BACE-N and at 3, 6, 9 and 12 months after inclusion within BACE-D. All questionnaires were preferably completed electronically, but paper versions were available for patients not familiar with electronic data collection. Within this study, only data from questionnaires were used.The outcome of this study was costs related to healthcare utilization aggregated over one-year of follow up and dichotomized as high and low. Having high costs related to healthcare utilization was defined as patients with costs in the top 25th percentile , 16.Healthcare utilization within BACE-N and BACE-D were self-reported and included: consultation to healthcare professionals (type and frequency), use of back medication , number of diagnostic examinations (type and frequency), number of days of hospitalization and/or rehabilitation stay (within BACE-N) and back operations. Within BACE-N, consultations to healthcare professionals and use of back medication were reported with a 3-months recall period at each timepoint of follow-up. Number of diagnostic examinations and days of hospitalization and/or rehabilitation stay were reported with a 3-months recall period at 3- and 6-months follow-up, and a 6-months recall period at 12-months follow-up. Back operations were reported with a 12-months recall period at 12-months follow-up. Within BACE-D, all variables, except back operations, were reported with a 3-months recall period at each timepoint of follow-up. Back operations were reported with a 12-months recall period at 12-months follow-up. Total costs of healthcare utilization per patient were estimated by multiplying frequency of use by unit costs collected from national pricelists  middle-aged back pain patients as well as patients with musculoskeletal disorders, and included the following self-reported variables measured at baseline:Sex , 39, 40 Age , 39, 40 Education level , 41 measEmployment status measured by the question “do you have a paying job?” and categorized into yes/no.Pain duration  measuredPain history  measuredFirst healthcare provider   or 12 (BACE-D) weeks prior to inclusion. Healthcare utilization prior to inclusion was self-reported and included: primary care consultations, use of back medication and number of diagnostic examinations. Total cost of healthcare utilization was estimated by multiplying frequency of use by unit costs collected from national pricelists  and characteristics of the study population. We therefore adjusted for potential covariates when evaluating the modifiable prognostic factors. Potential covariates were based on previous scientific literature on (primarily) middle-aged back pain patients as well as patients with musculoskeletal disorders, and included the following self-reported variables measured at baseline:p-values < 0.05 were considered statistically significant. All statistical tests were two-sided.All analyses are outlined in the statistical analysis plan published a priori  and prefThe flow of patients through the studies were reported with a flow chart according to the REMARK guidelines . Reasonsp > 0.05). Missing baseline data was handled by multiple imputation. Five multiple imputation datasets with 10 iterations were created using regression estimation. We did not impute missing outcome values, as the imputation model had poor predictive performance and caused a clear trend of values being overestimated. Instead, missing values on variables used to estimate the outcome score were filled in with; 1) each patient’s individual average of observed values for the variables: consultations to healthcare professionals and medication use, 2) a value of zero costs for the variables: diagnostic examinations, hospitalization, rehabilitation stay and back operations. Within BACE-D, missing value pattern was visually explored, and missingness at random was assumed. Missing values on variables used to estimate the outcome score were filled in with; 1) each patient’s individual average of observed values for the variables: consultations to healthcare professionals and medication use, 2) a value of zero costs for the variables: diagnostic examinations and back operations.Whitin BACE-N, missing value pattern was visually explored, and missingness at random was assumed. Also, we found evidence against the hypothesis that values were not missing completely at random  between each predefined modifiable prognostic factor and costs related to healthcare utilization (within BACE-N). The cost score was entered into the model as a dependent dichotomous variable . Linearity of continuous independent variables were examined using Box-Tidwell transformations . IndepenUnivariable and multivariable binary logistic regression models were used, as described above, to replicate findings from the identification analysis within BACE-D. The results were presented as crude and adjusted OR with 95% CI. The decision on whether findings were replicated were based on the direction and magnitude of the association, and the size of the CI for each of the predefined modifiable prognostic factors .To assess credibility of the identification analysis and possible bias introduced by the imputation procedure, the univariable and multivariable logistic regression analyses were performed on complete case data (within BACE-N).This study contains secondary analyses embedded in the BACE-N and BACE-D. Details of the sample size calculation related to the original aims of the cohorts are provided in the BACE-N and BACE-D protocols , 26. To A total of 452 (BACE-N) and 675 (BACE-D) patients were included in the identification and the replication sample, respectively. Table Within BACE-N, missing data ranged from 0.0 to 16.8% for included baseline variables and 18.4 to 26.0% for included follow-up variables. Total missingness was 4.9 and 23.3% for all baseline and follow-up values, respectively. Variables on medication use at 12-months follow-up had most missing values. Within BACE-D, missing data ranged from 0.0 to 11.8% for included baseline variables and 7.3 to 18.1% for included follow-up variables. Total missingness was 2.2 and 9.6% for all baseline and follow-up values, respectively. Variables on examination at 12-months follow-up had most missing values.Table A1 and A2 in the Additional file All continuous independent variables, aside from the two SF-36 variables, demonstrated a linear relationship with the dependent variable. Table p-values for the two SF-36 variables: In the complete case analysis of crude associations, the SF-36 mental second percentile group were not significantly associated with the outcome, and in the complete case analysis of adjusted associations, the SF-36 physical and mental second percentile groups were not significantly associated with the outcome.The sensitivity analysis  middle-aged back pain patients , 32, 35,The main limitation of this study is missing data on variables used to estimate the outcome score, thus we had to manually replace missing values. It is well-known that healthcare utilization is prone to missing data –58. AlsoThe main strength of the present study is that it was conducted in line with the PROGRESS framework including an identification and replication phase , pre-plaIn conclusion, this study identified and replicated four modifiable prognostic factors associated with high costs related to healthcare utilization among older people seeking primary care with a new episode of back pain: pain severity, disability, depression, and physical health-related quality of life. This study contributes to the on-going research into clinical pathways and has the potential to identify future target areas for intervention with the potential to reduce high costs related to healthcare utilization among older back pain patients. Due to differences in healthcare systems between countries, readers are advised to exercise caution with generalizability of the results to other healthcare systems.Additional file 1.Additional file 2.Additional file 3.


Many countries have an inefficient vaccination system, which hinders global exit from the COVID-19 pandemic. It is vital to summarize COVID-19 vaccination practices in countries with high vaccination coverage and provide implications for other countries. This study aimed to investigate China’s COVID-19 vaccination system and to summarize its implementation experience from a health system perspective.We conducted key informant interviews in five representative cities of China in late 2021. Guided by the health systems framework proposed by WHO, we developed our interview guidelines which included seven building blocks—leadership and governance, health workforce, vaccination service delivery, vaccination mobilization and communication, financing, access to vaccines, and information systems. Semi-structured interviews and COVID-19 vaccination policy documents were collected and coded using a thematic analysis approach.A total of 61 participants  were interviewed. We found that China adopted a whole-of-society approach with adequate government engagement and linked health and non-health sectors to promote COVID-19 vaccination. Key measures included the collaboration of multiple systems and departments from a governance perspective, allocating sufficient health workers and resources, large-scale vaccination mobilization and communication, expansion of vaccine financing channels, localized production and digital information systems. With the vaccination system strengthening, the two-doses vaccination coverage reached 89.5% for the total population but relatively lower coverage for older adults as of July 2022.Our study highlights the importance of a government-led whole-of-society approach to promote mass vaccination. The low vaccination coverage among older adults should be paid the greatest attention to. The experiences and lessons from China may serve as a reference for other countries. Mass COVID-19 vaccination has been in progress globally since the approval of COVID-19 vaccines. An efficient vaccination services delivery system and vaccine acceptance from the public are necessary to achieve high vaccination coverage. Due to the enormous target population for COVID-19 vaccination, each country faced universal challenges to relying on the current vaccination system to support mass COVID-19 vaccination. These challenges included the shortage of health workforce , inaccesHowever, most studies investigated the acceptance and willingness of COVID-19 vaccination from the recipient’s perspective , and fewAs of July 2022, 3.47 billion doses of COVID-19 vaccines had been administered in China, and 89.5% of Chinese had completed their initial two-dose vaccination protocol . AlthougThis study aimed to investigate China’s COVID-19 vaccination system and to summarize its implementation experience from a health system perspective. China’s experiences and lessons may serve as a reference for other low- and middle-income countries in promoting COVID-19 vaccination.We conducted key informant interviews in five representative cities of China from late September to early November 2021. One megacity, two prefectural-level cities and two county-level cities were selected to represent different socioeconomic layers and COVID-19 epidemic status in China. The selected megacity is located in eastern China and is highly developed, with more than 15 million residents. It experienced several large-scale COVID-19 outbreaks, with more than 650 cumulative COVID-19 confirmed cases as of our study time and once had strict containment measures. The two selected prefectural-level (county-level) cities represent the urban  regions in central and western China, respectively, with 1–5 (0.3–0.5) million residents in each city. The prefectural-level cities had only several small outbreaks, with 30–200 cumulative confirmed cases, whereas county-level cities rarely experienced an outbreak, with only a dozen cumulative confirmed cases. The Fudan University School of Public Health Ethics Committee approved the study protocol [FDU IRB#2018-10-0703].A multistage sampling process was applied to ensure the representativeness of the sample. In each selected city, we approached its Center for Disease Control and Prevention (CDC) and selected one community-level government agency and three community health centres. We interviewed 1–2 immunization programme directors of the local CDC, one community-level government staff member who participated in the COVID-19 vaccination campaigns, and 9–12 vaccination service workers from three community health centres where vaccination sites are located. In each community health centre, we interviewed one director of the health centre, one director of the vaccination site, one physician or nurse delivering vaccination services and one physician for pre-screening and treating side-effects following vaccination.We conducted semi-structured interviews with these key informants. Before the formal investigation, we developed interview guidelines and piloted them with 10 individuals in a non-study site. Each participant was informed of the interview purpose and was assured of voluntary participation and confidentiality. Participants signed the written consent, and we digitally recorded interviews. Among 63 individuals invited, 61 agreed to participate in the interview, including nine vaccination programme directors, four community-level government staff and 48 vaccination service workers   transcribed the recordings of interviews for mutual proofreading. We applied a thematic analysis approach  to analyEfficient leadership and governance are essential for mass COVID-19 vaccination. Each interviewed city established a specific leading group to develop and coordinate local implementation strategies for COVID-19 vaccination. With effective governance, responsibilities were clearly defined for different government departments. First, the governments’ community committees shouldered the primary responsibility for vaccination mobilization and communication for community residents. Each ministry, such as the health, education and transportation ministry, was responsible for vaccination mobilization and communication for workers in the responding industry. Second, the local CDCs were responsible for supplying and distributing COVID-19 vaccines, training vaccination service workers and providing technical guidance for vaccination. Third, community health centres and hospitals undertook the primary responsibility for vaccine injection work. Vaccination sites at health centres and hospitals identified target individuals with community committees and reported the daily vaccination progress to local CDCs Table .Table 2STo maintain societal and economic development, China adopted a two-step strategy for the COVID-19 vaccination rollout  are free of charge and fully financed by general taxes, while non-EPI vaccines are fully paid for by recipients. In early 2021, the Chinese government stipulated that COVID-19 vaccines were not included in the EPI but were free for residents. Seventy percent of fees for COVID-19 vaccines and vaccination were directly covered by social health insurance, while the remaining was funded through reallocated general taxes. This was the first time that social health insurance funds paid for vaccine fees nationally. Vaccination workers can receive vaccination fees as incentives.The National Healthcare Security Administration adopted strategic purchasing of COVID-19 vaccines and negotiated the vaccine price with enterprises. Through several rounds of negotiations with domestic vaccine manufacturers, the purchase price of inactivated COVID-19 vaccines was set at no more than 14.2 US dollars (1 dollar = 6.36 Chinese yuan) per dose in early 2021 and further dropped to around 6.3 and 3.1 US dollars per dose in the consequent periods.Sufficient supply and distribution of COVID-19 vaccines can ensure access to vaccines as prerequisites of mass vaccination. China set up a national-level assurance group to promote the production of COVID-19 vaccines developed by various technical platforms. It emphasized localized production to ensure the supply and availability of COVID-19 vaccines. As the main vaccines used in China, inactivated vaccines can be transported more easily and economically than other technologies such as messenger RNA (mRNA) vaccines. A surveillance system was used to track each dose of COVID-19 vaccine. In general, provincial CDCs took responsibility for procuring and distributing COVID-19 vaccines. Provincial CDCs collected data on vaccination demand from all cities in the province, centralized procurement with vaccine manufacturers and distributed vaccines to each vaccination site. The CDC was able to rapidly adjust the distribution plans according to vaccination demand. Moreover, syringes and other vaccination consumables were purchased by vaccination sites, billed to vaccination fees and covered by health insurance funds.Well-functioning information systems are necessary to record vaccination status and side-effects. China digitally tracked the status of each COVID-19 vaccine dose through vaccine circulation and vaccination management information systems. A tracking code on each packaged box of the COVID-19 vaccine made it possible to track each dose by scanning the code. Through this information system, every vaccination site could identify vaccine inventory and report it to local CDCs daily.The side-effects following COVID-19 vaccination need to be treated promptly. In China, vaccination workers must record suspected side-effects in the adverse event following immunization (AEFI) record book. Side-effects and the treatments for AEFI must be promptly reported to health administrations. Severe AFEIs require a daily report of the detailed conditions including onset, symptoms and treatment of the case.With the strengthening of the vaccination system, around 3.47 billion doses and 239 doses per 100 individuals had been administered in China as of early July 2022 (Fig. This study investigated the implementation experiences of mass COVID-19 vaccination in China according to the WHO health systems framework [WHO proposed the WoS governance system as guidance for pandemic preparedness and response . It requVaccination resources are usually in severe shortage when facing mass vaccination. To meet the enormous demand for COVID-19 vaccination, China adjusted its traditional vaccination system with dedicated vaccinators and vaccination sites. Before COVID-19 vaccination campaigns, vaccination services were only delivered by dedicated vaccinators at community health centres . There wCOVID-19 vaccine misinformation and hesitancy were prevalent globally , 36, andWith the vaccination system strengthening, the two-dose vaccination coverage reached nearly 90% as of July 2022. However, among older adults aged 60+, only 83.8% had completed the initial two-dose vaccination, and only 65.7% had received a booster dose . Low vacAnother challenge was the fatigue among vaccination workers. Hefty workloads with extended working hours have caused fatigue, exhaustion and psychological disturbances . It is eWe acknowledge that there may be limitations in our findings. First, qualitative interviews introduced a degree of unavoidable subjectivity and limited extrapolation, although we interviewed people at different levels of the public health system and in different geographic areas. There may be some bias since participants were chosen to be interviewed because of their position and expertise. Second, the vaccination coverage data for the studied cities were unavailable, so we cannot differentiate the performance of local vaccination campaigns. Third, this study focused on the supply side of vaccination campaigns, which complements our understanding based on previous studies on the demand side.Our study summarized China’s practices from seven building blocks of the COVID-19 vaccination system according to the experiences of workers and stakeholders working in various organizations. It highlights the importance of a WoS approach with adequate government engagement to promote mass vaccination. The low vaccination coverage among older adults should be given the greatest attention. The experiences and lessons from China may serve as a reference for other countries, especially for low- and middle-income countries, with adaptations to local contexts.


Escherichia coli (ESBL-EC) and Salmonella spp. (ESBL-SA) isolates from agrifood and human sources in Canada from 2012 to 2017, and (2) describe the distribution of ESBL genotypes among these isolates. All data were obtained from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). CIPARS analysed samples for the presence of ESBLs through phenotypic classification and identified beta-lactamase genes  using polymerase chain reaction (PCR) and whole genome sequencing (WGS). The prevalence of PCR-confirmed ESBL-EC in agrifood samples ranged from 0.5% to 3% across the surveillance years, and was detected most frequently in samples from broiler chicken farms. The overall prevalence of PCR-confirmed ESBL-SA varied between 1% and 4% between 2012 and 2017, and was most frequently detected in clinical isolates from domestic cattle. The TEM-CMY2 gene combination was the most frequently detected genotype for both ESBL-EC and ESBL-SA. The data suggest that the prevalence of ESBL-EC and ESBL-SA in Canada was low (i.e. <5%), but ongoing surveillance is needed to detect emerging or changing trends.Resistance to beta-lactam antimicrobials caused by extended-spectrum beta-lactamase (ESBL)-producing organisms is a global health concern. The objectives of this study were to (1) summarise the prevalence of potential ESBL-producing  Beta-lactam antimicrobials are one of the most widely used classes of antimicrobials in human and veterinary medicine, and resistance to these drugs is a global public health concern , 2. ExteESBLs pose a significant challenge to the effectiveness of infection control and antimicrobial stewardship efforts, as the genes encoding the ESBL enzymes are mostly located on or near mobile genetic elements, such as plasmids, insertion sequences, and transposons , 8. The E. coli isolates from both human and poultry sources in the Netherlands found 19% of the human isolates contained the same ESBL genes as farm poultry isolates and 39% of ESBL-producing E. coli isolates found in retail chicken meat were associated with genotypes also found in the human samples [E. coli may occur between live poultry, poultry products and humans, most likely through the food-chain [Because of gene transfer within and between bacterial genera, it is difficult to characterise the transmission pathways of ESBL genes in bacterial populations and host species . However samples . This suod-chain . It is aE. coli (ESBL-EC) and Salmonella spp. (ESBL-SA) from human and agrifood sources in Canada from 2012 to 2017, and (2) describe the distribution of ESBL genotypes among these isolate.To date, there have been few studies examining ESBL-producing Enterobacteriaceae across several human and animal sources in Canada. This study formed part of a doctoral thesis , and theE. coli and Salmonella isolates were obtained from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), a national surveillance programme that monitors human and animal antimicrobial use (AMU), and AMR in select bacteria from humans, animals and retail food [Salmonella and E. coli) collected by CIPARS between 2012 and 2017 from the agrifood surveillance components, and between 2012 and 2016 for the human surveillance component, as the 2017 data were not available at the time of analysis. CIPARS uses active surveillance to obtain samples and associated risk factor information from farms, slaughter plants and from grocery stores. The CIPARS farm component uses Canadian sentinel farms to monitor AMU and AMR in broiler chickens, feedlot beef cattle, dairy cattle, grower-finisher pigs, and turkeys. The CIPARS farm broiler chicken component collects placement (flocks sampled at the time of chick placement on the farm) and pre-harvest (flocks sampled at least 1 week before shipment for slaughter) samples [Salmonella, Campylobacter and generic E. coli. Additionally, CIPARS tests Salmonella isolates from human and veterinary diagnostic submissions for resistance [All ail food . This stSalmonella isolates) or Saint-Hyacinthe, Québec (agrifood E. coli isolates). Briefly, minimum inhibitory concentration (MIC) values for E. coli and Salmonella were determined using a broth microdilution method, and susceptibility categories were interpreted according to Clinical and Laboratory Science Institute (CLSI) guidelines [E. coli or Salmonella isolate with a ceftiofur MIC ≥4 μg/ml or a ceftriaxone MIC ≥0.5 μg/ml. Until 2016, we conducted phenotypic confirmation of ESBL-producers using CLSI confirmatory disk tests using disks containing cefotaxime, cefotaxime-clavulanic acid, ceftazidime and ceftazidime-clavulanic acid, in addition to polymerase chain reaction (PCR) testing [blaCMY−2, blaCTX−M, blaSHV, blaTEM and blaOXA. Isolates that lacked blaCMY−2, but contained a potential ESBL  underwent WGS by the National Microbiology Laboratory  to differentiate between the variants of the ESBL enzymes (blaCMY−2/blaTEM isolates underwent sequencing on the NextSeq platform (Illumina). AMR prediction from whole genome sequences was carried out with the staramr tool [The methods used for sample collection and antimicrobial susceptibility testing are described in detail in the CIPARS annual reports . All susidelines . We defi testing . In 2016 enzymes . SequencA subset of the CIPARS retail samples collected between 2012 and 2014 underwent additional testing for potential ESBL-producing Enterobacteriaceae using a selective media isolation approach. Frozen retail meat samples were thawed and enriched in 225 ml of buffered peptone water and incubated at 37°C for 18–24 h. Incubate broth was inoculated onto CHROMagar™ ESBL plates and incubated at 37°C for 18–24 h. Presumptive positive samples were subcultured onto MacConkey agar. Presumptive ESBL-producing colonies were further subcultured onto a tryptic soy agar plate and incubated. Disk diffusion phenotypic testing was then performed as described above. Presumptive isolates from meat samples were then submitted for phenotypic testing to the National Microbiology Laboratory  and further submitted for WGS testing at the National Microbiology Laboratory .blaCTX−M or blaOXA genes or if it was a known ESBL variant of blaTEM or blaSHV; unfortunately, this was only possible to confirm for isolates that underwent WGS. Although we recognise that isolates containing the blaCMY−2 gene are not true ESBL producers, we classified isolates containing the CblaMY−2 gene with one of the true extended-spectrum beta-lactamase genes to be potential ESBL producers. The prevalence of ESBL-SA and ESBL-EC was calculated and defined as the total number of ESBL-EC or ESBL-SA isolates detected by PCR divided by the total number of samples submitted for testing for E. coli or Salmonella. The proportion of E. coli and Salmonella isolates that were potential ESBL-producers each year was also examined and was defined as the total number of ESBL-EC or ESBL-SA isolates detected genotypically (by PCR) divided by the total number of E. coli or Salmonella isolates recovered. Exact confidence intervals  were calculated for all prevalence and proportion estimations. Summary tables were created for PCR-confirmed ESBL producers for both human and agrifood species. For both Salmonella and E. coli, the data were examined to identify any differences in the prevalence of agrifood ESBLs between years, regions and host species using univariable logistic regression in STATA [Surveillance data for each year were received from the laboratory in a Microsoft Excel 2016 spreadsheet. All isolate susceptibility and ESBL testing data were compiled into a summary spreadsheet, and all descriptive analyses were performed in Microsoft Excel 2016. An isolate was defined as ESBL-producing if it contained the in STATA . DiffereE. coli by CIPARS between 2012 and 2017 was 25 353, and the total number of E. coli isolates recovered was 21 517. A total of 394 PCR-confirmed ESBL-EC were detected for an overall prevalence of 1.8% (95% CI 1.7–2.0) and an ESBL-EC proportion of 1.6% . The highest prevalence of PCR-confirmed ESBL-EC was in broiler chickens on farm  in the prevalence of potential ESBL-EC across years, animal species/food commodities, or sampling region in Canada.Univariable logistic regression models revealed no significant differences . Furthermore, a total of 163 potential ESBL-EC isolates underwent sequencing to further characterise the ESBL variants . Overall, 2% of the Salmonella isolates collected between 2012 and 2017 were potential ESBL-producers. The annual prevalence of potential ESBL-SA ranged between a low of 0.5% (95% CI 0.3–0.8) in 2012 and a high of 1.6% (95% CI 1.3–1.9) in 2014  accounted for 71% of the total ESBL-SA detected  were detected among samples collected from CIPARS active surveillance components; among these components, the highest prevalence of potential ESBL-SA appeared in isolates collected from turkey farms  and swine farms .The highest percentage of PCR-confirmed ESBL-SA were detected among clinical isolates collected by passive surveillance (91%), and diagnostic cases from domestic cattle  of all Salmonella isolates identified as potential ESBL-producers.CIPARS tested 13 894 human clinical and 2016 . Over thP > 0.05) in the prevalence of potential ESBL-SA across years, animal species/food commodities or sampling region in Canada.Univariable logistic regression models revealed no significant differences (P > 0.05) in the prevalence of potential ESBL-SA detected between years, gender, region or age class.Univariable logistic regression models were used to examine differences in the prevalence of potential ESBL-SA in humans across years, gender, region in Canada and age class. There were no differences  of ESBL-EC in animals and meat and ESBL-SA among animal, meat and human isolates in Canada, but several different ESBL genotypes were identified across species and surveillance components.E. coli across food animal species highlighted a prevalence of 60% among individual broiler rectal isolates [E. coli and Salmonella isolates recovered from broiler chickens on farm, at abattoir, and at retail have demonstrated resistance to ceftriaxone  [The CIPARS surveillance data demonstrated that the prevalence of ESBL genes in broiler chickens and chicken meat in Canada is generally lower than rates reported by other countries, although prevalence rates of ESBL producers from broiler chickens in the literature vary widely by region. A German study found a prevalence of ESBL-producing Enterobacteriaceae of 1.7% in cloacal and environment samples in seven broiler flocks upon chick arrival at the farm . In contisolates . Differeisolates  for diseisolates , 27. By isolates , 27. Sinisolates , 28. Sinosporin) . Adoptioosporin) , 29–33. osporin) , 29–32. vs. conventional) may facilitate the transmission of ESBL-producing organisms [It may also be important to consider other farm-related factors that may account for differences in prevalence of ESBL-producing organisms. Several farm management factors, such as exposure to contaminated water or feed, water acidification and type of production system  of the potential ESBL-EC isolates detected by CIPARS over the study period were found in retail chicken. The overall prevalence of potential ESBL-EC in retail chicken was 3.4% (95% CI 2.8–4.1) using traditional culture methods, which is relatively low compared to data published in other regions. For example, 37% of retail chicken samples in a study in Germany were ESBL-EC positive , and a FE. coli carriage compared to the general population [E. coli carriage. Considering the mobility of ESBL genes and the potential for humans to be exposed through the food chain or direct contact, this highlights an important area for ongoing surveillance.Despite the low prevalence of potential ESBL-EC demonstrated in farm broiler chicken and retail chicken in Canada, ongoing surveillance and research is needed, as many Canadians are exposed to bacteria from chicken through the food chain, and chicken may represent an important reservoir for ESBL-producing organisms and ESBL genes , 37, 38.In our study, the use of a selective medium identified six additional isolates containing ESBL genes in retail chicken. This slightly increased the prevalence of potential ESBL-EC in over this study period, suggesting that the choice of medium could have important implications for the recovery of ESBL-EC and the ongoing surveillance of these organisms. Future surveillance efforts should carefully consider the choice of methods used for phenotypic and/or molecular detection of ESBL-producing organisms among samples. Although appropriateness of the methods will depend on the objectives of the surveillance system, selective media can improve detection of microorganisms that are present in low numbers . PreviouDespite the evidence that selective media may enhance the sensitivity of diagnostic screening, the use of ESBL-detecting selective media is not common practice in clinical or research settings, and the benefits of using this approach are still controversial and debated , 43. ThiSalmonella enterica in healthy chickens and swine in Belgium highlighted that 96.6% of chicken-derived Salmonella isolates carried an ESBL gene, and 71.4% of swine-derived Salmonella isolates carried an ESBL gene [β-lactam antimicrobial amoxicillin is the most frequently used antimicrobial in Belgian broiler production, with 43% of sampled farms reporting use [Salmonella contamination in retail chicken in South Korea found that 63.6% of Salmonella isolates from conventionally raised broiler chicken were ESBL-producers [The prevalence of potential ESBL-SA was highest among clinical isolates collected from domestic cattle. Clinical isolates are recovered from animals that would not be immediately entering the food chain and would therefore not present the same risk to public health compared to isolates from healthy animals on farm or at slaughter. However, these animals could potentially be a source of environmental contamination, and transfer ESBL-SA to other animals in the herd that may be entering the food chain or come into direct contact with humans, so it is important to continue to monitor clinical isolates. In contrast, the prevalence of potential ESBL-SA among food animal isolates on farm, at abattoir and at retail was very low. There are few studies investigating the prevalence of ESBL-SA in food-producing species compared to ESBL-EC, hence it is challenging to compare our results to other findings. A 2014 study of SBL gene . Our datting use . In contting use . Furtherroducers , which iThe annual proportion of potential ESBL-SA among human clinical isolates collected by CIPARS ranged between 0.11% and 0.72%, with an overall prevalence of 0.39% between 2012 and 2016. These data are similar to reports from the National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) in the United States, which reported ESBL-SA prevalence of 0.34% and 0.28% among human clinical isolates in 2014 and 2015, respectively , 50. Theβ-lactam antimicrobials. This also undermines the importance of integrated surveillance of ESBLs and other important resistance determinants in humans and along the food chain. However, this does not necessarily represent direct evidence for the zoonotic transfer of ESBL genes through food contamination. The majority of the TEM-CMY2 isolates were from clinical Salmonella cases in domestic cattle rather than from animals close to slaughter or from retail meat; any spread of ESBL genes from clinically sick animals to humans is more likely through direct contact or via the environment than through food.Importantly, the most common potential ESBL-SA genotype in this study was TEM-CMY2 among both the human clinical and agrifood isolates. This highlights the One Health nature of the issue of AMR, and the potential for humans and animals to share similar genes encoding resistance to the critically important drugs, such as vs. TEM-2) cannot be determined without further analysis such as sequencing, making it challenging to determine whether these organisms are true ESBL-producers. Additionally, PCR only identifies the ESBL genes for which primers are available, so novel or rare ESBL gene variants may not be detected using only PCR. WGS can produce more precise information on the specific genes and plasmids compared to PCR, which can help gain greater insight into different transmission routes and the complex epidemiology of ESBL-producing Enterobacteriaceae, including molecular relatedness of isolates collected from different species [A potential limitation of our study is the relatively small number of isolates that underwent further molecular characterisation via WGS. Although PCR results can help inform which ESBL genes are circulating in each of the host species examined, the specific genotype (e.g. TEM-1  species . Sequenc species . ObtainiIn conclusion, this study highlighted the relatively low prevalence of potential ESBL-EC and ESBL-SA across animals, food and humans in Canada. Between 2012 and 2017, the total number of ESBL-EC and ESBL-SA isolates obtained from CIPARS surveillance generally decreased, though this trend was not statistically significant. This may be a result of the 2014 poultry industry initiative that banned the preventative use of ceftiofur in chicken, as this has resulted in a decrease in AMU and AMR in poultry and people in Canada . Despite


Patients with familial hypercholesterolemia (FH) have an increased risk of having abnormally high low-density lipoprotein cholesterol (LDL-C) levels. One of the main groups of drugs used for FH is statins. However, even with statins, most patients with FH do not achieve their pre-defined therapeutic LDL-C goals. Therefore, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) serve to decrease LDL-C levels in that population.A total of 838 articles were found after searching the databases of PubMed, MEDLINE, and Cochrane Library. After including only full-text peer-reviewed articles published in the last 10 years, 67 articles remained. Thirteen articles were put through the Cochrane bias assessment tool to screen for bias. After a strict quality assessment based on the criteria, eight articles were extracted and included in this systematic review.The data extraction from these studies showed that alirocumab and evolocumab were efficacious in decreasing LDL-C levels and achieving the pre-defined LDL-C goals. Many parameters influenced the strength of the LDL-C reduction: sample size of the population, genetic structure of the patients affected by FH, length of the trial, or baseline lipid-lowering therapy used. Therefore, one must consider several other factors while evaluating the percent reduction of PCSK9i. This review is limited because it did not comment on these drugs' cardiovascular outcomes or mortality benefits. In addition, some of the articles used in this systematic review have small sample sizes and short trial times, limiting the long-term evaluation of these drugs. Familial hypercholesterolemia (FH) is a common inherited metabolic disorder because of genetic mutations, which eventually cause drastically elevated low-density lipoprotein cholesterol (LDL-C) levels . FH can It is crucial that patients are properly screened and early diagnosis followed by strict medical intervention and lifestyle changes because those left untreated are at greater risk of premature myocardial infarction (MI) and coronary heart disease (CHD) . DiagnosIn addition to the clinical diagnosis of FH, there are three well-known formal criteria for making the diagnosis. These include the Simon Broome criteria, the United States "Make Early Diagnosis to Prevent Early Deaths" (US MEDPED) diagnostic criteria, and the Dutch Lipid Clinic Network diagnostic criteria . The maiUpon diagnosis, treatment should begin as soon as possible to lower the LDL-C levels by at least 50% . Since oIn addition, it is recommended that patients with HeFH who are at high cardiovascular risk should aim to maintain their LDL-C levels at <70 or <100 mg/dL . HoweverMethodsThe methods and results for this systematic review are reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines following screening selection.Search StrategyWe used the electronic databases PubMed, MEDLINE, and Cochrane Library to look for articles using Medical Subject Headings (MeSH) and keywords to obtain the most relevant reviews and studies for analysis. The keywords included: "PCSK9 Inhibitors", "Alirocumab," "Evolocumab," "Familial Hypercholesterolemia," or "Hyperlipoproteinemia Type ll." We used several combinations of Boolean to put together the keywords according to the algorithm used in PubMed. The MeSH search used to obtain the articles was: (("Proprotein Convertase 9"[Majr]) OR "Proprotein Convertases/antagonists and inhibitors"[Majr]) AND ( "Hyperlipoproteinemia Type II/drug therapy"[Majr] OR "Hyperlipoproteinemia Type II/prevention and control"[Majr] OR "Hyperlipoproteinemia Type II/therapy"[Majr] ). The articles were then screened to highlight those most relevant to the search question and selected according to the inclusion/exclusion criteria.Inclusion and Exclusion CriteriaThe articles analyzed in this systematic review used the following inclusion criteria: 1) papers from the past 10 years; (2) randomized controlled trials (RCTs) and clinical trials; (3) published in English; (4) human subjects; (5) full reports (not just abstracts). To exclude papers, the following criteria were used: (1) unpublished literature; (2) grey literature; (3) papers discussing pharmacokinetics or pharmacodynamics of the PCSK9 inhibitors; or (4) papers discussing any drugs except evolocumab or alirocumab. The flow chart showing the methodology used to select articles for inclusion is explained in Figure  papers fArticle ScreeningInitial screening was done by going through the title or abstract to weed out the articles deemed unqualified. After that, the inclusion and exclusion criteria described above were used. The remaining articles were read in detail, checked using the Cochrane risk assessment, and finalized to be included in the review.Critical Appraisal of StudiesWe critically appraised our screened articles using the Cochrane risk-of-bias tool. The bias risk assessment looked at seven causes of potential bias, and a summary for each clinical trial in this review is given in Table ResultsA total of 838 articles were generated from keywords, MeSH, eligibility criteria, and databases. Of the 838 articles, 768 were from PubMed, and 70 were from Cochrane Library. After applying the basic inclusion criteria, only 67 articles remained on PubMed. PubMed and Cochrane library articles were then screened by their titles and abstracts. Fifty-four articles were screened out because of topic irrelevance and duplicates. Thirteen articles were critically appraised using the Cochrane bias assessment tool. Five were removed because they did not meet 70% of the assessment criteria. Eight articles met the criteria and they were only RCTs. The PRISMA flow diagram is shown in Figure The reviewed clinical trials differed in design, population, and primary endpoints. However, the efficacy in lowering to a target LDL level and adverse events associated with the PCSK9i was a common part of each RCT. This is summarized in Table Our systematic review included only RCTs and clinical trials. The eight RCTs chosen for review were randomized, double-blind, placebo-controlled trials. The articles' primary outcome was the percent changes in LDL-C concentration at several different set periods. However, the secondary endpoints included a mixture of percent changes: apolipoprotein (Apo) B, non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol lipoprotein(a) (Lp(a)), high-density lipoprotein cholesterol (HDL-C), triglycerides, or apolipoprotein A (ApoA1). In addition, all the articles also commented on the safety of the alirocumab or evolocumab administration by mentioning the number and type of adverse events encountered. All of the articles commented on the safety of the drugs by examining the injection-site reactions and treatment-emergent serious adverse events.EfficacyBlom et al. selected 59 (85.5%) patients taking high-intensity statin, 50 (72.5%) patients on ezetimibe, 10 (14.5%) on lomitapide, and 10 (14.5%) on apheresis . RegardiGinsberg et al. too selected all patients receiving statin therapy (72.9% were on a high-intensity statin) . There wHovingh et al. selected 440 patients to receive the evolocumab treatment vs. placebo (standard of care (SOC)) . Of the Kastelein et al. selected 735 patients and randomized them into two studies, FH l and FHII with 486 patients and 249 patients,respectively . Forty-sIn 2017, Kastelein et al. included patients who had been enrolled in four 78-week ODYSSEY studies: FH l NCT01623115), FH ll (NCT01709500), LONG TERM (NCT01507831), and HIGH FH (NCT01617655) [, FH ll  or placebo . GenotypIn the same year, 2014, Raal et al. included 331 patients in another study, who were randomly assigned to receive evolocumab 140 mg once every two weeks, evolocumab 420 mg monthly, or placebo once every two weeks. Of the enrolled patients, 42 were women and 89% were white . Around Santos and co-authors had 158 randomized patients, and 157 patients in their clinical trial, who either received evolocumab (104 patients) or a placebo (53 patients) . EighteeDiscussionThis review examined the efficacy of PCSK 9 inhibitors, alirocumab and evolocumab, in patients with FH (heterozygous or homozygous). Statins have been the drug of choice for HeFH for decades; however, there are still patients who either cannot tolerate statins or are just not adequate to lower LDL-C levels to the therapeutic range. For instance, in a cross-sectional study conducted in the Netherlands on 1249 patients with HeFH, approximately 96% were taking statin drugs; however, only about 26% reached the LDL-C goal of <2.5mmol/l . These fEfficacyThis systematic review of PCSK9 inhibitor drugs  found statistically and clinically significant reductions of different magnitudes in LDL-C when added to statin therapy in patients diagnosed with FH. Even though all of the studies used in the systematic review showed some form of LDL-C reduction in the treatment arm compared to the placebo, the strength of this result is based on the characteristic of the population tested and the drug used. Out of the eight articles we analyzed in this systematic review, five had patients diagnosed with HeFH, and three used patients diagnosed with HoFM. In patients with HeFH, the trials for alirocumab had a larger number of patients than the trials evaluating evolocumab (1257 vs. 440). In addition, studies evaluating alirocumab also ran for a longer time than evolocumab (78 weeks vs. 52 weeks or 12 weeks). The lower number of patients can introduce higher variability in results, which might not be seen in a study with a higher number of patients. The studies analyzing patients with HeFH showed that the PCSK9 inhibitors reduced LDL-C significantly and brought patients' LDL-C to a pre-defined goal. In addition, it significantly decreased the levels of triglycerides, total cholesterol, non-HDL-C, Apo B, and Lp(a) and increased the levels of HDL-C, which are the healthy lipoproteins. It is well known that high levels of LDL, the bad cholesterol, are a major cause of heart disease; therefore, these drugs help patients reduce the risk for cardiovascular disease. We will first analyze the articles about HeFH and then move on to HoFH.In 2016, Ginsberg et al. conducted a trial to evaluate the efficacy of alirocumab in a specific group of patients who, in particular, had a high level of LDL-C at screening. They explored the difference between their results and other clinical trials with similar experiments to explain that the strength of LDL-C reductionneeds to be evaluated in the context of the population examined and the design of the experiment. They noticed that the LDL-C reductions were lower than in the ODYSSEY program, including those with FH patients . Even thIn 2015, Kastelein et al. had randomized 735 patients in two studies: one with alirocumab 75 mg and another with alirocumab 150 mg . The stuHovingh et al. and Raal et al. discussed the efficacy and safety of evolocumab in patients diagnosed with HeFH ,17. CompThis systematic review has two papers on HoFH: one examining the efficacy and safety of alirocumab , and oneOn the other hand, unclassified patients in terms of genetic mutation had a variable LDL-C reduction (ranging from -56.6% to 42.9%) , suggestSantos and colleagues showed a significant reduction in the LDL-C in their trial of pediatric patients diagnosed with HeFH and treated with evolocumab in addition to statin therapy . Like thLimitationsAs can be seen from each of the studies used in this systematic review, the patients were on some lipid-lowering therapy at baseline  in addition to the PCSK9 inhibitor used in the trial. The patients were taking varying doses of different strength statins, and PCSK9 inhibitors were used because these patients were not reaching the target LDL-C levels. However, in reality, there is a step-wise approach implemented, where the current therapy the patient receives is maximized, and if it is not tolerated, another drug is added. Some of the studies analyzed did not use this approach, so it would be valuable for future studies to follow this protocol. In addition, this systematic review did not analyze the relation of the PCSK9 inhibitors to reducing cardiovascular events or mortality. Lastly, despite the benefit of using a RCT, some of the reviews used in this systematic review continued the experiment using an open-label treatment design. Open-label treatment designs can introduce bias into the experiment that cannot be eliminated because of the lack of comparative control.PCSK9 inhibitors  have proven themselves to be efficacious drugs. A significant portion of the patients reached their pre-defined LDL-C goals, and several other lipid parameters were significantly improved. Even though all trials showed a reduction in LDL-C with alirocumab or evolocumab, the strength of this reduction depends on the sample size and length of the trial. Some of the articles in this analysis have a small sample size making it difficult to extrapolate the data. Short trial lengths also make it difficult to comment on the long-term efficacy of the drugs. In addition, most patients were on baseline statin therapy  or ezetimibe, and a step-wise approach to using PCKS9 inhibitors (maximizing the dosage of the current lipid-lowering therapy before starting PCSK9 inhibitors) would be beneficial. However, high cardiovascular-risk patients might not have enough time to make a step-wise approach. In addition, long-term drug safety and mortality benefits of the PCSK9 inhibitors should be considered in future studies. In conclusion, these PCSK9 inhibitors are efficacious and potent drugs for FH.