Analysis of spin in the reporting of studies of topical treatments of photoaged skin.

BACKGROUND: Spin-reporting that distorts the interpretation of results-is not unusual within scientific literature.

OBJECTIVE: To appraise strategies of spin among placebo-controlled double-blind clinical trials of topical treatments for photoaged skin.

METHODS: A systematic review of the literature was performed to identify placebo-controlled double-blind clinical trials of topical treatments for photoaged skin. A survey of spin strategies was developed and applied to the cohort of identified studies.

RESULTS: The systematic review led to the identification of 20 studies in which various types of spin strategies, broadly classified as either inappropriate statistical analyses or inappropriate interpretation of results, were used. The most commonly used strategies included use of multiple primary outcomes (95%), inappropriate extrapolation of results from specific outcomes to global improvements (95%), focus on within-group comparisons (75%), and focus on interim analyses to give more weight to nonsignificant findings (65%).

LIMITATIONS: Classification of spin strategies was subjective and might not encompass all the methods used in the published literature.

CONCLUSION: Findings in this study inform efforts to reduce spin in the dermatologic literature.