567 research outputs found

    Propensity score methodology for confounding control in health care utilization databases

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    Propensity score (PS) methodology is a common approach to control for confounding in nonexperimental studies of treatment effects using health care utilization databases. This methodology offers researchers many advantages compared with conventional multivariate models: it directly focuses on the determinants of treatment choice, facilitating the understanding of the clinical decision-making process by the researcher; it allows for graphical comparisons of the distribution of propensity scores and truncation of subjects without overlapping PS indicating a lack of equipoise; it allows transparent assessment of the confounder balance achieved by the PS at baseline; and it offers a straightforward approach to reduce the dimensionality of sometimes large arrays of potential confounders in utilization databases, directly addressing the “curse of dimensionality” in the context of rare events. This article provides an overview of the use of propensity score methodology for pharmacoepidemiologic research with large health care utilization databases, covering recent discussions on covariate selection, the role of automated techniques for addressing unmeasurable confounding via proxies, strategies to maximize clinical equipoise at baseline, and the potential of machine-learning algorithms for optimized propensity score estimation. The appendix discusses the available software packages for PS methodology. Propensity scores are a frequently used and versatile tool for transparent and comprehensive adjustment of confounding in pharmacoepidemiology with large health care databases

    Metformin and the risk of renal cell carcinoma: a case-control analysis

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    Metformin use has been associated previously with a decreased risk of cancer, but its association with renal cell carcinoma has not yet been investigated in observational studies. We aimed to explore the association between the use of metformin and other antidiabetic drugs and the risk of renal cell carcinoma (RCC). We carried out a case-control analysis in the UK-based Clinical Practice Research Datalink. We included individuals with an incident RCC between January 1995 and December 2013 younger than the age of 90 years. Six controls per case were matched on age, sex, calendar time, general practice, and number of years of active history in the Clinical Practice Research Datalink before the index date. We included BMI, smoking, alcohol consumption, hypertension, and diabetes mellitus as potential confounders in a multivariate model using conditional logistic regression to calculate odds ratios with 95% confidence intervals, and we carried out a sensitivity analysis restricted only to diabetic cases and controls. Long-term use of metformin was not associated with an altered relative risk of RCC (≥30 prescriptions, adjusted odds ratio 1.18, 95% confidence interval 0.88-1.58), nor was use of other antidiabetic drugs. Results in the sensitivity analysis including only diabetic cases and controls were largely the same. Use of metformin or other antidiabetic drugs was not associated with a materially altered risk of RCC. Further studies are warranted

    Exercise Addiction in Athletes and Leisure Exercisers: The Moderating Role of Passion

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    Background and aims Recently, empirical research has linked obsessive passion to the etiology of exercise addiction, and the conceptual reason behind the fact that the latter is more prevalent in athletes than leisure exercisers has been challenged. The aim of this study was to determine the link between exercise addiction and harmonious passion, obsessive passion, and dedication to sports, in the context of athletic levels. A sample comprised of low- and high-level competitive athletes and non-competitive leisure exercisers (n = 313) was examined, in a cross-sectional design, in which participants completed the Spanish validated versions of the Exercise Addiction Inventory (Sicilia, Alías-García, Ferriz, & Moreno-Murcia, 2013) and Passion Scale (Chamarro et al., 2015). Results Obsessive passion and dedication to sports emerged as strong predictors of exercise addiction. Competitive athletes scored higher than leisure exercisers on all measures. Athletes competing at low and high levels only differed in dedication to their sports from each other. Team-sports athletes reported greater harmonious and obsessive passions, and dedication to sports, but not different exercise addictions, than people taking part in individual sports. Conclusions The concept of exercise addiction is not a plain and independent construct and may not reflect a psychological dysfunction in the athletic population. Athletes could interpret exercise addiction screening-items differently from non-athletes. Athletes in team sports report greater passion and dedication than those practicing individual sports

    Correlates of total physical activity among middle-aged and elderly women

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    Information on correlates of total physical activity (PA) levels among middle-aged and elderly women is limited. This article aims to investigate whether total daily PA levels are associated with age, body mass index, smoking, drinking status, and sociodemographic factors

    Prospective study of job stress and risk of infections in Swedish adults

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    ObjectivesPsychological stress may influence both susceptibility and severity of infections. Although work-related stress is a widespread concern among many employees, few studies have been conducted with the focus on work stressors and infections. We therefore aimed to investigate this association in a prospective cohort study.MethodsOur study included 25 029 employed individuals who filled-out a questionnaire in September 1997 and were followed through record linkages until retirement or December 2016. Work stress was assessed at baseline using a Swedish version of the Demand-Control Questionnaire, whereas hospital contacts related to infections were identified from the National Patient Register. We fitted extensions of the standard Cox model to account for recurrent infections.ResultsIn total, we observed 8257 infections. Individuals in the third tertile of job demand had a 13% higher hazard of infections (HR=1.13; 95% CI=1.03 to 1.24) compared with individuals in the first tertile, specifically an increased incidence of upper respiratory tract infections (HR=1.15; 95% CI=1.00 to 1.33) and urinary tract infections (HR=1.31; 95% CI=1.09 to 1.57) was found. Employees with the highest job control (third tertile) had no lower risk of infections than individuals in the lowest tertile (HR=1.02; 95% CI=0.92 to 1.13). When combining the demand and control dimensions into job strain scale, no association between high job strain and infections was observed (HR=1.08; 95% CI=0.97 to 1.21).ConclusionHigh job demand, but not low job control, is associated with an increased occurrence of infections. No difference was observed in workers with high strain jobs compared with those with low strain jobs
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