Applying two approaches to detect unmeasured confounding due to time-varying variables in a self-controlled risk interval design evaluating COVID-19 vaccine safety signals, using myocarditis as a case example.

We test the robustness of the self-controlled risk interval (SCRI) design in a setting where time between doses may introduce time-varying confounding, using both negative control outcomes (NCOs) and quantitative bias analysis (QBA). All vaccinated cases identified from 5 European databases between 1 September 2020 and end of data availability were included. Exposures were doses 1-3 of the Pfizer, Moderna, AstraZeneca, and Janssen COVID-19 vaccines; outcomes were myocarditis and otitis externa (NCO). The SCRI used a 60-day control window and dose-specific 28-day risk windows, stratified by vaccine brand and adjusted for calendar time. The QBA included two scenarios: (i) baseline probability of the confounder was higher in the control window and (ii) vice versa. The NCO was not associated with any of the COVID-19 vaccine types or doses except Moderna dose 1 (IRR = 1.09, 95%CI 1.01-1.09). The QBA suggested even the strongest literature-reported confounder (COVID-19; RRmyocarditis = 18.3) could only explain away part of the observed effect from IRR = 3 to IRR = 1.40. The SCRI seems robust to unmeasured confounding in the COVID-19 setting, although a strong unmeasured confounder could bias the observed effect upward. Replication of our findings for other safety signals would strengthen this conclusion.

"Catheter replacement in catheter-associated urinary tract infection: current state of evidence ".

PURPOSE: Catheter associated urinary tract infection (CAUTI) is the most common healthcare associated infection. A significant knowledge gap exists regarding the necessity of catheter replacement as part of CAUTI treatment. Current guidelines recommend replacement for faster recovery and to prevent recurrences, but adherence is low. In this systematic review, we aimed to assess the available evidence regarding catheter replacement for CAUTI. MATERIALS AND METHODS: Eligible studies investigated the effect of catheter replacement in CAUTI on clinical outcomes and/or recurrence rates, irrespective of catheter type or setting. We searched electronic literature databases from inception to October 15th, 2023. Information was extracted regarding setting, eligibility criteria, definition of CAUTI, timing of replacement, and outcomes. RESULTS: Of the 257 identified studies, four were considered relevant and included. Two were randomized controlled trials (RCT) and two were observational studies. One RCT showed higher rates of clinical recovery and lower recurrence rates in the replacement group, while results of the other RCT favoured retainment, with a lower recurrence rate in the retainment group, although longer antimicrobial treatment in this group. Two observational studies were inconclusive. CONCLUSIONS: Current guidelines rely heavily on recommendations from a single study, emphasizing the need for further research. The burden of catheter replacement, including patient discomfort and resource impact, warrants careful consideration. A randomized trial is essential to provide more evidence on the effect of catheter replacement on clinical outcomes including CAUTI recurrence.

Ten things to remember about propensity scores.

Propensity score methods are popular to control for confounding in observational biomedical studies of risk factors or medical treatments. This paper focused on aspects of propensity score methods that often remain undiscussed, including unmeasured confounding, missing data, variable selection, statistical efficiency, estimands, the positivity assumption, and predictive performance of the propensity score model.

Lipid Levels and Risk of Diabetic Polyneuropathy in 2 Danish Type 2 Diabetes Cohorts.

BACKGROUND AND OBJECTIVES: Reduction of blood lipids may aid in preventing diabetic polyneuropathy (DPN), but evidence remains conflicting. We investigated the association between lipid parameters and DPN risk in individuals with type 2 diabetes mellitus (T2DM). METHODS: We conducted a population-based cohort study of individuals with newly diagnosed T2DM and a cross-sectional study using a clinically recruited T2DM cohort. Triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and non-HDL cholesterol were measured in routine diabetes care. Each lipid parameter was categorized according to the latest cutoffs in clinical guidelines on dyslipidemia. DPN was assessed with validated hospital diagnosis codes in the population-based cohort and with the Michigan Neuropathy Screening Instrument questionnaire in the clinical cohort. We calculated hazard ratios (HRs) using Cox regression and prevalence ratios (PRs) using Poisson regression. RESULTS: We included 61,853 individuals in the population-based cohort (median age 63 [quartiles 54-72] years) and 4,823 in the clinical cohort (median age 65 [quartiles 57-72] years). The incidence rate of hospital-diagnosed DPN in the population-based cohort was 3.6 per 1000 person-years during a median follow-up of 7.3 years. Achieving guideline targets for HDL, LDL, and non-HDL cholesterol showed no association with DPN risk. By contrast, adjusted HRs (95% CI) for DPN were 1.02 (0.89-1.18) for triglyceride levels between 150 and 204 mg/dL (1.7-2.3 mmol/L) and 1.28 (1.13-1.45) for levels >204 mg/dL (2.3 mmol/L). In the clinical cohort with a DPN prevalence of 18%, DPN associated strongly with triglycerides >204 mg/dL (2.3 mmol/L) with an adjusted PR (95% CI) of 1.40 (1.21-1.62). The prevalence of DPN was modestly elevated for individuals with HDL cholesterol <39 mg/dL (1.0/1.3 mmol/L) in men and <50 mg/dL (1.3 mmol/L) in women (PR 1.13 [0.99-1.28]) and for individuals with non-HDL cholesterol >131 mg/dL (3.4 mmol/L) (PR 1.27 [1.05-1.52]). In both cohorts, spline models showed an increasing risk of DPN starting from triglyceride levels >124 mg/dL (1.4 mmol/L). All results were similar among statin users. DISCUSSION: High triglyceride levels are a strong DPN risk factor. Future intervention studies shall determine whether triglyceride reduction is more important for DPN prevention than reduction of other lipids.

[Causes of death: the uncertainty behind the numbers]. / Doodsoorzaken: de onzekerheid achter de cijfers.

When a person dies in the Netherlands it is legally required to report the cause of death. In most cases however, there is uncertainty when classifying causes of death. Additional postmortem diagnostics such as a CT scan or autopsy do not always provide absolute certainty. Data on causes of death can be used to determine what are, on a population level, relevant health problems. One must be cautious to fully rely on these data for making policy or financing healthcare and research. Firstly, incorrectly classifying the cause of death can give a distorted view of the underlying causes. Secondly, relevant health problems, such as obesity, might be overlooked in the statistics when they are not clearly a cause of death.

Directed acyclic graphs in clinical research.

Directed acyclic graphs (DAGs), or causal diagrams, are graphical representations of causal structures that can be used in medical research to understand and illustrate potential bias, including bias arising from confounding, selection, and misclassification. Further, they provide guidance for researchers about how to address a potential bias.

Dependent observations in clinical research.

For many statistical methods that are commonly used in medical research, it is assumed that observations are independent. However, when this assumption is violated, alternative methods may be needed. In this paper, we describe why an analysis that ignores the dependencies within the data may provide biased results and outline possible alternatives. This paper aims to create awareness among researchers, readers, and reviewers for this possible source of bias in medical research.

Do postoperative hemodynamic parameters add prognostic value for mortality after surgical aortic valve replacement?

Background: Although various hemodynamic parameters to assess prosthetic performance are available, prosthesis-patient mismatch (PPM) is defined exclusively by effective orifice area (EOA) index thresholds. Adjusting for the Society of Thoracic Surgeons predicted risk of mortality (STS PROM), we aimed to explore the added value of postoperative hemodynamic parameters for the prediction of all-cause mortality at 5 years after aortic valve replacement. Methods: Data were obtained from the Pericardial Surgical Aortic Valve Replacement (PERIGON) Pivotal Trial, a multicenter prospective cohort study examining the performance of the Avalus bioprosthesis. Candidate predictors were assessed at the first follow-up visit; patients who had no echocardiography data, withdrew consent, or died before this visit were excluded. Candidate predictors included peak jet velocity, mean pressure gradient, EOA, predicted and measured EOA index, Doppler velocity index, indexed internal prosthesis orifice area, and categories for PPM. The performance of Cox models was investigated using the c-statistic and net reclassification improvement (NRI), among other tools. Results: A total of 1118 patients received the study valve, of whom 1022 were eligible for the present analysis. In univariable analysis, STS PROM was the sole significant predictor of all-cause mortality (hazard ratio, 1.40; 95% confidence interval, 1.26-1.55). When extending the STS PROM with single hemodynamic parameters, neither the c-statistics nor the NRIs demonstrated added prognostic value compared to a model with STS PROM alone. Similar findings were observed when multiple hemodynamic parameters were added. Conclusions: The STS PROM was found to be the main predictor of patient prognosis. The additional prognostic value of postoperative hemodynamic parameters for the prediction of all-cause mortality was limited.

Transfusion of ever-pregnant donor red blood cells and mortality of male patients.

Previous studies found exposure to red blood cell transfusions from female donors who have been pregnant reduces survival in male patients compared to exposure to male donor products, but evidence is not consistent. We postulate the previously observed association is modified by offspring sex, with an expected increased mortality risk for male patients receiving units from female donors with sons. Here, marginal structural models were used to assess the association between exposure to units from ever-pregnant donors, ever-pregnant donors with sons and ever-pregnant donors with daughters, and mortality. Clinical data were collected on first-ever transfusion recipients in the Netherlands and donor data were supplemented with information about offspring sex and date of birth. In this analysis, 56,825 patients were included, of whom 8,288 died during follow-up. Exposure to red blood cell units from everpregnant donors with sons was not associated with increased all-cause mortality risk among male transfusion recipients (hazard ratio [HR] 0.91, 95% confidence interval 0.83-1.01). Exposure to ever-pregnant donors, irrespective of offspring sex, was associated with mortality in male patients aged between 18 and 50 years (ever-pregnant donors: HR 1.81, 95% CI 1.31-2.51) compared to male donor units, but was protective in female patients. This study suggests that the observed increased mortality risk for exposure to red blood cell units from parous female donors does not depend on offspring sex. The increased risk of mortality seen in younger adult male patients is consistent with previous observations, but the underlying biological mechanism could not be identified in this study.

Let's Agree to Disagree on Operative Versus Nonoperative Treatment for Distal Radius Fractures in Older People: Protocol for a Prospective International Multicenter Cohort Study.

BACKGROUND: Distal radius fractures are the most frequently encountered fractures in Western societies, typically affecting patients aged 50 years and older. Although this is a common injury, the best treatment for these fractures in older patients is still under debate. OBJECTIVE: This prospective study aims to compare the outcome of operatively and nonoperatively treated distal radius fractures in the older population. Only patients with distal radius fractures for which equipoise regarding the optimal treatment exists will be included. METHODS: This prospective international multicenter observational cohort study will be designed as a natural experiment. Natural experiments are observational studies in which treatment allocation is determined by factors outside the control of the investigators but also (largely) independent of patient characteristics. Patients aged 65 years and older with an acute distal radius fracture will be considered for inclusion. Treatment allocation (operative vs nonoperative) will be based on the local preferences of the treating hospital either in Switzerland or the Netherlands. Hence, the process governing treatment allocation resembles that of randomization. Patients will be identified after treatment has been initiated. Based on the radiographs and baseline information of the patient, an expert panel of 6 certified trauma surgeons from 2 regions will provide their treatment recommendation. Only patients for whom the experts disagree on treatment recommendations will ultimately be included in the study (ie, for whom there is a clinical equipoise). For these patients, both operative and nonoperative treatment of distal radius fractures are viable, and treatment choice is predominantly determined by personal or local preference. The primary outcome will be the Patient-Rated Wrist Evaluation score at 12 weeks. Secondary outcomes will include the Physical Activity Score for the Elderly, the EQ questionnaire, pain, the living situation, range of motion, complications, and radiological outcomes. By including outcomes such as living situation and the Physical Activity Score for the Elderly, which are not relevant for younger cohorts, valuable information to tailor treatment to the needs of the older population can be gained. According to the sample size collection, which was based on the minimal important clinical difference of the Patient-Rated Wrist Evaluation, 92 patients will have to be included, with at least 46 patients in each treatment group. RESULTS: Enrollment began in July 2023 and is expected to continue until summer 2024. The final follow-up will be 2 years after the last patient is included. CONCLUSIONS: Although many trials on this topic have previously been published, there remains an ongoing debate regarding the optimal treatment for distal radius fractures in older patients. This observational study, which will use a fairly new methodological study design, will provide further information on treatment outcomes for older patients with distal radius fractures for which to date equipoise exists regarding the optimal treatment. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/52917.

Real-World Evidence to Inform Regulatory Decision Making: A Scoping Review.

Real-world evidence (RWE) is increasingly considered in regulatory decision making. When, and to which extent, RWE is considered relevant by regulators likely depends on many factors. This review aimed to identify factors that make RWE necessary or desirable to inform regulatory decision making. A scoping review was conducted using literature databases (PubMed, Embase, Emcare, Web of Science, and Cochrane Library) and websites of regulatory agencies, health technology assessment agencies, research institutes, and professional organizations involved with RWE. Articles were included if: (1) they discussed factors or contexts that impact whether RWE could be necessary or desirable in regulatory decision making; (2) focused on pharmacological or biological interventions in humans; and (3) considered decision making in Europe or North America, or without a focus on a specific region. We included 118 articles in the scoping review. Two major themes and six subthemes were identified. The first theme concerns questions addressable with RWE, with subthemes epidemiology and benefit-risk assessment. The second theme concerns contextual factors, with subthemes feasibility, ethical considerations, limitations of available evidence, and disease and treatment-specific aspects. Collectively, these themes encompassed 43 factors influencing the need for RWE in regulatory decisions. Although single factors may not make RWE fully necessary, their cumulative influence could make RWE essential and pivotal in regulatory decision making. This overview contributes to ongoing discussions emphasizing the nuanced interplay of factors influencing the necessity or desirability of RWE to inform regulatory decision making.

Learning healthcare systems in cardiology: A qualitative interview study on ethical dilemmas of a learning healthcare system.

Background: Implementation of an LHS in cardiology departments presents itself with ethical challenges, including ethical review and informed consent. In this qualitative study, we investigated stakeholders' attitudes toward ethical issues regarding the implementation of an LHS in the cardiology department. Methods: We conducted a qualitative study using 35 semi-structured interviews and 5 focus group interviews with 34 individuals. We interviewed cardiologists, research nurses, cardiovascular patients, ethicists, health lawyers, epidemiologists/statisticians and insurance spokespersons. Results: Respondents identified different ethical obstacles for the implementation of an LHS within the cardiology department. These obstacles were mainly on ethical oversight in LHSs; in particular, informed con sent and data ownership were discussed. In addition, respondents reported on the role of patients in LHS. Respondents described the LHS as a possibility for patients to engage in both research and care. While the LHS can promote patient engagement, patients might also be reduced to their data and are therefore at risk, according to respondents. Conclusions: Views on the ethical dilemmas of a LHSs within cardiology are diverse. Similar to the literary debate on oversight, there are different views on how ethical oversight should be regulated. This study adds to the literary debate on oversight by highlighting that patients wish to be informed about the learning activities within the LHS they participate in, and that they wish to actively contribute by sharing their data and identifying learning goals, provided that informed consent is obtained.

Comparison of likelihood penalization and variance decomposition approaches for clinical prediction models: A simulation study.

Logistic regression is one of the most commonly used approaches to develop clinical risk prediction models. Developers of such models often rely on approaches that aim to minimize the risk of overfitting and improve predictive performance of the logistic model, such as through likelihood penalization and variance decomposition techniques. We present an extensive simulation study that compares the out-of-sample predictive performance of risk prediction models derived using the elastic net, with Lasso and ridge as special cases, and variance decomposition techniques, namely, incomplete principal component regression and incomplete partial least squares regression. We varied the expected events per variable, event fraction, number of candidate predictors, presence of noise predictors, and the presence of sparse predictors in a full-factorial design. Predictive performance was compared on measures of discrimination, calibration, and prediction error. Simulation metamodels were derived to explain the performance differences within model derivation approaches. Our results indicate that, on average, prediction models developed using penalization and variance decomposition approaches outperform models developed using ordinary maximum likelihood estimation, with penalization approaches being consistently superior over the variance decomposition approaches. Differences in performance were most pronounced on the calibration of the model. Performance differences regarding prediction error and concordance statistic outcomes were often small between approaches. The use of likelihood penalization and variance decomposition techniques methods was illustrated in the context of peripheral arterial disease.

Look left, look right: censoring in clinical research.

In this methodology editorial, the problem of censored survival (or time-to-event) data in clinical research is discussed. In case of censored observations, part of the observation time for some participants in a study is unobserved, which means that measures such as an average survival time cannot be calculated. Instead, censored survival time should explicitly be accounted for in the analysis of a study, for example using the Kaplan-Meier method. Implications of censoring and how to deal with it in the analysis of a study or when reading a research paper are discussed.

Nonoperative treatment of multiple rib fractures, the results to beat: International multicenter prospective cohort study among 845 patients.

BACKGROUND: Optimal treatment (i.e. nonoperative or operative) for patients with multiple rib fractures remains debated. Studies that compare treatments are rationalized by the alleged poor outcomes of nonoperative treatment. METHODS: The aim of this prospective international multicenter cohort study (between January 2018 and March 2021) with one-year follow-up, was to report contemporary outcomes of nonoperatively treated patients with multiple rib fractures. Including 845 patients with three or more rib fractures. Primary outcome was in-hospital mortality. Secondary outcomes included hospital length of stay (HLOS), (pulmonary) complications, and quality of life. RESULTS: Mean age was 57.7 ± 17.0 years, median Injury Severity Score was 17 (13-22) and the median number of rib fractures was 6 (4-8). In-hospital mortality rate was 1.5% (n = 13), 112 (13.3%) patients had pneumonia and four (0.5%) patients developed a symptomatic non-union. The median HLOS was 7 (4-13) days, and median intensive care unit length of stay was 2 (1-5) days. Mean EQ-5D-5L index value was 0.83 ± 0.18 one year after trauma. Polytrauma patients had a median HLOS of 10 (6-18) days, a pneumonia rate of 17.6% (n = 77) and mortality rate of 1.7% (n = 7). Elderly patients (≥65 years) had a median HLOS of 9 (5-15) days, a pneumonia rate of 19.7% (n = 57) and mortality rate of 4.1% (n = 12). CONCLUSIONS: Overall, nonoperative treatment of patients with multiple rib fractures shows low mortality and morbidity rate and good quality of life after one year. Future studies evaluating the benefit of operative stabilisation should use contemporary outcomes to establish the therapeutic margin of rib fixation. LEVEL OF EVIDENCE: Level III, Therapeutic/Care Management.

Rapid Response to Remdesivir in Hospitalised COVID-19 Patients: A Propensity Score Weighted Multicentre Cohort Study.

INTRODUCTION: Remdesivir is a registered treatment for hospitalised patients with COVID-19 that has moderate clinical effectiveness. Anecdotally, some patients' respiratory insufficiency seemed to recover particularly rapidly after initiation of remdesivir. In this study, we investigated if this rapid improvement was caused by remdesivir, and which patient characteristics might predict a rapid clinical improvement in response to remdesivir. METHODS: This was a multicentre observational cohort study of hospitalised patients with COVID-19 who required supplemental oxygen and were treated with dexamethasone. Rapid clinical improvement in response to treatment was defined by a reduction of at least 1 L of supplemental oxygen per minute or discharge from the hospital within 72 h after admission. Inverse probability of treatment-weighted logistic regression modelling was used to assess the association between remdesivir and rapid clinical improvement. Secondary endpoints included in-hospital mortality, ICU admission rate and hospitalisation duration. RESULTS: Of 871 patients included, 445 were treated with remdesivir. There was no influence of remdesivir on the occurrence of rapid clinical improvement (62% vs 61% OR 1.05, 95% CI 0.79-1.40; p = 0.76). The in-hospital mortality was lower (14.7% vs 19.8% OR 0.70, 95% CI 0.48-1.02; p = 0.06) for the remdesivir-treated patients. Rapid clinical improvement occurred more often in patients with low C-reactive protein (≤ 75 mg/L) and short duration of symptoms prior to hospitalisation (< 7 days) (OR 2.84, 95% CI 1.07-7.56). CONCLUSION: Remdesivir generally does not increase the incidence of rapid clinical improvement in hospitalised patients with COVID-19, but it might have an effect in patients with short duration of symptoms and limited signs of systemic inflammation.

Effects of COVID-19 on diabetes care among dutch diabetes outpatients.

AIMS: The COVID-19 pandemic impacted diabetes care by reducing diabetes outpatient visits and diabetes-related screening due to allocation of healthcare resources. Yet the impact of COVID-19 on diabetes outpatients has not been extensively evaluated. This study aimed to assess the effect of the COVID-19 pandemic on diagnostics and intermediate outcomes of outpatient diabetes care pre- and during COVID. METHODS: This observational cohort study included 8,442 diabetes patients in the Dutch Pediatric and Adult Registry of Diabetes (DPARD) visiting diabetes outpatient clinics in 2019 and 2021. A mixed-effects regression analysis was used to examine differences in target achievement of HbA1c, BMI, blood pressure, LDL-cholesterol, eGFR, and the difference in mean HbA1c between 2019 and 2020 among n = 1,426 outpatients who visited in both years. Analyses were adjusted for age, sex, and BMI. RESULTS: A 22.7% (21.6-23.8%, p < 0.001) decline in outpatient volume was observed during the pandemic (2020). BMI, lipid spectrum, kidney function, and HbA1c were assessed less frequently in 2020 than in 2019. In 2020, compared to 2019, the median HbA1c level increased by 2.2% (1.0 mmol/mol, p = 0.035) and the percentages of patients with known HbA1C meeting targets below 10, 8, 7% (86, 64, and 53 mmol/mol) decreased by 0.5%, 1.7% and 1.4%, respectively. Target blood pressure ≤ 130/80 mmHg was achieved more often in 2020 (15.0% versus 18.3%, p = 0.018), while HbA1c ≤ 86 mmol/mol was achieved less (89.3% versus 87.1%, p = 0.001), among diabetes outpatients seen in both 2019 and 2020. In patients visiting both years, HbA1c was 2.3% (1.9 mmol/l, 95% CI 1.2-2.5, p < 0.001) lower during the pandemic than in the prepandemic (2019). CONCLUSIONS: The COVID pandemic was associated with a marked reduction in patient volume in diabetes outpatient care among five hospitals. Among patients who received outpatient care both before and during the pandemic period, HbA1c control and blood pressure control enhanced during the pandemic. Re-evaluation of current diabetes outpatient care organization is warranted to ensure optimal diabetes care in future times.

Dynamics in cardiac surgery: trends in population characteristics and the performance of the EuroSCORE II over time.

OBJECTIVES: The aim of this study was to investigate the performance of the EuroSCORE II over time and dynamics in values of predictors included in the model. METHODS: A cohort study was performed using data from the Netherlands Heart Registration. All cardiothoracic surgical procedures performed between 1 January 2013 and 31 December 2019 were included for analysis. Performance of the EuroSCORE II was assessed across 3-month intervals in terms of calibration and discrimination. For subgroups of major surgical procedures, performance of the EuroSCORE II was assessed across 12-month time intervals. Changes in values of individual EuroSCORE II predictors over time were assessed graphically. RESULTS: A total of 103 404 cardiothoracic surgical procedures were included. Observed mortality risk ranged between 1.9% [95% confidence interval (CI) 1.6-2.4] and 3.6% (95% CI 2.6-4.4) across 3-month intervals, while the mean predicted mortality risk ranged between 3.4% (95% CI 3.3-3.6) and 4.2% (95% CI 3.9-4.6). The corresponding observed:expected ratios ranged from 0.50 (95% CI 0.46-0.61) to 0.95 (95% CI 0.74-1.16). Discriminative performance in terms of the c-statistic ranged between 0.82 (95% CI 0.78-0.89) and 0.89 (95% CI 0.87-0.93). The EuroSCORE II consistently overestimated mortality compared to observed mortality. This finding was consistent across all major cardiothoracic surgical procedures. Distributions of values of individual predictors varied broadly across predictors over time. Most notable trends were a decrease in elective surgery from 75% to 54% and a rise in patients with no or New York Heart Association I class heart failure from 27% to 33%. CONCLUSIONS: The EuroSCORE II shows good discriminative performance, but consistently overestimates mortality risks of all types of major cardiothoracic surgical procedures in the Netherlands.