The Effect of Bye Weeks on Injury Event Rates in the Canadian Football League.

Objective: To determine the effect of bye weeks (no practices or games) on the injury event rate in the Canadian Football League (CFL).

Design: Historical (retrospective) cohort study.

Setting: CFL.

Development of a Framework for Establishing 'Gold Standard' Outbreak Data from Submitted SARS-CoV-2 Genome Samples.

Submitted genomic data for respiratory viruses reflect the emergence and spread of new variants. Although delays in submission limit the utility of these data for prospective surveillance, they may be useful for evaluating other surveillance sources. However, few studies have investigated the use of these data for evaluating aberration detection in surveillance systems.

Target trial framework for determining the effect of changes in training load on injury risk using observational data: a methodological commentary.

In recent years, a large focus has been placed on managing training load for injury prevention. To minimise injuries, training recommendations should be based on research that examines causal relationships between load and injury risk. While observational studies can be used to estimate causal effects, conventional methods to study the relationship between load and injury are prone to bias.

Principles of musculoskeletal sport injuries for epidemiologists: a review.

Background: Musculoskeletal injuries are a common occurrence in sport. The goal of sport injury epidemiology is to study these injuries at a population level to inform their prevention and treatment.

Main Body: This review provides an overview of musculoskeletal sport injuries and the musculoskeletal system from a biological and epidemiologic perspective, including injury mechanism, categorizations and types of sport injuries, healing, and subsequent injuries.

Effect modification of cancer on the association between dysphagia and mortality in early idiopathic inflammatory myopathies.

Objective: The interplay between dysphagia, cancer, and mortality in idiopathic inflammatory myopathies (IIM) has not been carefully studied. The aim of this study was to investigate possible effect modification of cancer on the association between dysphagia and mortality in early IIM.

Methods: A multi-center cohort of 230 adult IIM patients with dysphagia assessment within 6 months of disease onset was assembled.

metamedian: An R package for meta-analyzing studies reporting medians.

When performing an aggregate data meta-analysis of a continuous outcome, researchers often come across primary studies that report the sample median of the outcome. However, standard meta-analytic methods typically cannot be directly applied in this setting. In recent years, there has been substantial development in statistical methods to incorporate primary studies reporting sample medians in meta-analysis, yet there are currently no comprehensive software tools implementing these methods.

Standard error estimation in meta-analysis of studies reporting medians.

We consider the setting of an aggregate data meta-analysis of a continuous outcome of interest. When the distribution of the outcome is skewed, it is often the case that some primary studies report the sample mean and standard deviation of the outcome and other studies report the sample median along with the first and third quartiles and/or minimum and maximum values. To perform meta-analysis in this context, a number of approaches have recently been developed to impute the sample mean and standard deviation from studies reporting medians.

Implementing Multiple Imputation for Missing Data in Longitudinal Studies When Models are Not Feasible: An Example Using the Random Hot Deck Approach.

Purpose: Researchers often use model-based multiple imputation to handle missing at random data to minimize bias. However, constraints within the data may sometimes result in implausible values, making model-based imputation infeasible. In these contexts, we illustrate how random hot deck imputation can allow for plausible multiple imputation in longitudinal studies.

Investigating the Effect of Return-to-Play Timing After Injury on Performance: Does the Analysis Answer the Research Objective?

Return-to-play decision making should be based on all the advantages and disadvantages of return to play for athletes, not just the risk of injury. For competitive athletes, this includes the effect of early versus delayed return to sport on performance. In this paper, we address the questions "How can I estimate the effect of injury on the individual's performance at return to play?" and "What is the effect of delaying return to sport on the individual's performance?".

Observed Injury Rates Did Not Follow Theoretically Predicted Injury Risk Patterns in Professional Human Circus Artists.

Objective: Identifying which types of athletes have increased injury risk (ie, predictive risk factors) should help develop cost-effective selective injury prevention strategies. Our objective was to compare a theoretical injury risk classification system developed by coaches and rehabilitation therapists, with observed injury rates in human circus acts across dimensions of physical stressors, acrobatic complexity, qualifications, and residual risks.

Design: Descriptive epidemiological study.

Causal effects, workload and injury risk: The importance of specifying the research question.

Objectives: To illustrate why the research question determines whether and how sport medicine investigators should adjust for workload when interested in interventions or causal risk factors for injury.

Design: Theoretical conceptualization.

Methods: We use current concepts of causal inference to demonstrate the advantages and disadvantages of adjusting for workload through different analytic approaches when evaluating causal effects on injury risk.

Patient-specific finite element analysis of heart failure and the impact of surgical intervention in pulmonary hypertension secondary to mitral valve disease.

Pulmonary hypertension (PH), a chronic and complex medical condition affecting 1% of the global population, requires clinical evaluation of right ventricular maladaptation patterns under various conditions. A particular challenge for clinicians is a proper quantitative assessment of the right ventricle (RV) owing to its intimate coupling to the left ventricle (LV). We, thus, proposed a patient-specific computational approach to simulate PH caused by left heart disease and its main adverse functional and structural effects on the whole heart.

NT-proBNP, hs-cTnT, and CRP predict the risk of cardiopulmonary outcomes in systemic sclerosis: Findings from the Canadian Scleroderma Research Group.

Objective: The aim of this study was to determine the independent value of N-terminal pro b-type natriuretic peptide, high-sensitivity cardiac troponin T, and C-reactive protein to predict onset of cardiopulmonary disease in a large, multi-center systemic sclerosis cohort followed prospectively.

Methods: Subjects from the Canadian Scleroderma Research Group registry with data on N-terminal pro b-type natriuretic peptide, high-sensitivity cardiac troponin T, and C-reactive protein were identified. Outcomes of interest were death, systolic dysfunction (left ventricular ejection fraction < 50% or medications for heart failure), pulmonary arterial hypertension by right heart catheterization, pulmonary hypertension by cardiac echocardiography (systolic pulmonary artery pressures ⩾ 45 mmHg), arrhythmias (pacemaker/implantable cardiac defibrillator or anti-arrhythmic medications), and interstitial lung disease.

Balancing Inferential Integrity and Disclosure Risk via Model Targeted Masking and Multiple Imputation.

There is a growing expectation that data collected by government-funded studies should be openly available to ensure research reproducibility, and so is the concern on data-privacy. A strategy to protect individuals' identity is to release multiply imputed (MI) synthetic datasets with masked sensitivity values (Rubin, 1993). However, information loss or incorrectly specified imputation models can weaken or invalidate the inferences obtained from the MI-datasets.

Predicting Injury Risk Over Changes in Physical Activity in Children Using the Acute:Chronic Workload Ratio.

Limited research exists on the relationship between changes in physical activity levels and injury in children. In this study, we investigated the prognostic relationship between changes in activity, measured by the acute:chronic workload ratio (ACWR), and injury in children. We used data from the Childhood Health, Activity, and Motor Performance School Study Denmark (2008-2014), a prospective cohort study of 1,660 children aged 6-17 years.

HSV Esophagitis in an Immunocompetent 17-Year-Old.

Herpes Simplex Virus (HSV) esophagitis is a relatively rare form of infectious esophagitis. Typically, patients with viral esophagitis are immunocompromised. HSV esophagitis in an immunocompetent patient is uncommonly reported.

Causal simulation experiments: Lessons from bias amplification.

Recent theoretical work in causal inference has explored an important class of variables which, when conditioned on, may further amplify existing unmeasured confounding bias (bias amplification). Despite this theoretical work, existing simulations of bias amplification in clinical settings have suggested bias amplification may not be as important in many practical cases as suggested in the theoretical literature. We resolve this tension by using tools from the semi-parametric regression literature leading to a general characterization in terms of the geometry of OLS estimators which allows us to extend current results to a larger class of DAGs, functional forms, and distributional assumptions.

Effect of preschool childcare on school-aged children's adiposity in Quebec, Canada.

Background: Regulated public childcare must follow nutrition and physical activity guidelines, but the impact of public childcare on childhood adiposity is unclear.

Objectives: To estimate the effects of universal preschool childcare on children's BMI in elementary school in Quebec, Canada, and whether the effects differed in children from more or less advantaged families.

Methods: For 1657 children enrolled in the Quebec Longitudinal Study of Child Development (1998-2010), BMI z-scores (BMIz) from 6 to 13 years were regressed on the childcare used from 2 to 5 years, adjusted for pre-childcare variables.

Association between gastroprotective agents and risk of incident interstitial lung disease in systemic sclerosis.

Objectives: Although interstitial lung disease (ILD) occurs in over half of systemic sclerosis (SSc) patients and represents a leading cause of mortality, there are currently no preventative strategies. We evaluated if gastroprotective agents were associated with a lower incident risk of SSc-ILD.

Methods: An SSc cohort without clinically apparent ILD at baseline was constructed from the Canadian Scleroderma Research Group registry.

The semiparametric accelerated trend-renewal process for recurrent event data.

Recurrent event data arise in many biomedical longitudinal studies when health-related events can occur repeatedly for each subject during the follow-up time. In this article, we examine the gap times between recurrent events. We propose a new semiparametric accelerated gap time model based on the trend-renewal process which contains trend and renewal components that allow for the intensity function to vary between successive events.

Treatment of a Large Multiloculated Liver Abscess with Intra-Abscess Antibiotic Instillation.

This report describes a 15-year-old with an 11.1 × 8.2 × 8.

Association of Autologous Hematopoietic Stem Cell Transplantation in Systemic Sclerosis With Marked Improvement in Health-Related Quality of Life.

Objective: To quantify the magnitude, domains, and duration of change in health-related quality of life (HRQoL) in patients with systemic sclerosis (SSc) who underwent autologous hematopoietic stem cell transplantation (HSCT) as compared to SSc patients with similar characteristics who did not undergo autologous HSCT.

Methods: The study was designed as a retrospective study comparing SSc patients who underwent autologous HSCT and SSc patients who met the criteria for transplantation but were treated with conventional care. Outcomes included scores on the 36-item Short Form (SF-36) health survey and the Health Assessment Questionnaire (HAQ) and its disease-specific symptom scales.