Key Points
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Epidemiology is the study of the distribution and determinants of disease in populations
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The recent increase in computer power has enabled epidemiological studies to be conducted with very large databases and to explore multiple risk factors of outcomes within the same analysis
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The main epidemiological study designs are cross-sectional, cohort and case–control
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Clinical trials, a type of cohort study, can test the superiority, noninferiority or equivalence of two or more treatments
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Absolute and attributable risks are more meaningful to the clinician and patient than relative risks
Abstract
Epidemiology research is a vital component of clinical studies in all medical fields. This Review provides a brief introduction to the methodology and interpretation of population and clinical epidemiology studies of musculoskeletal disorders. Data sources (including 'big data' and the issue of missing data), study design (cross-sectional, case–control and cohort studies, including clinical trial design) and the interpretation of study results are discussed with examples from the field of rheumatology, particularly using findings in patients with rheumatoid arthritis. Two or more treatments can be compared in clinical trials using a variety of study designs including superiority, noninferiority or equivalence. The different types of risk in epidemiological studies—absolute, attributable, background and relative—are important concepts in epidemiological research and their relative usefulness to clinicians and patients should be considered carefully. The potential pitfalls and challenges of generalizing the results of epidemiological studies to understanding disease aetiology and to clinical practice are also emphasized. The aim of the Review is to help readers to critically appraise published articles that use epidemiological designs or methods.
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Symmons, D. Epidemiology research in rheumatology—progress and pitfalls. Nat Rev Rheumatol 11, 631–638 (2015). https://doi.org/10.1038/nrrheum.2015.92
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DOI: https://doi.org/10.1038/nrrheum.2015.92
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