Misclassification of study designs in the dermatology literature

Abstract

Background: The appropriate classification of study designs is important for review and assessment of the relevant scientific literature as a basis for decision making; however, little is known about whether study designs have been appropriately reported in the dermatology literature. Objective: We aimed to validate the study designs in the dermatology literature and investigate discrepancies between author-reported and actual study designs. Methods: We reviewed all issues of 3 major dermatology journals from January to December 2016. A total of 295 original articles investigating associations between exposures and health outcomes were included for analysis. We used a validated algorithm to classify the study designs. Results: Among the 295 articles, 174 (59.0%) clearly mentioned the study design in the text. All interventional studies were correctly classified on the basis of study design (n = 42); however, 35 of 132 observational studies (26.5%) showed discrepancies between the author-reported and actual study design. When the author-reported design was a prospective cohort, retrospective cohort, or case-control study (n = 61), approximately half of the studies were misclassified by the authors (n = 30). Limitations: We analyzed only 3 journals in the dermatology field. Conclusions: Our findings revealed substantial discrepancies between author-reported and actual study designs in the dermatologic literature, particularly among observational studies.