Evaluation of Spin in the Abstracts of Systematic Reviews and Meta-Analyses for the Pharmacological Treatment of Type 2 Diabetes Mellitus

Background: Currently, there is a growing body of research demonstrating that spin — the misinterpretation and distortion of a study’s findings — is common in different fields of medicine. To our knowledge, no study has investigated its presence in systematic reviews focused on diabetic therapies.Methods: We performed a cross-sectional study by searching MEDLINE and Embase for systematic reviews focused on pharmacologic treatments for type 2 diabetes mellitus. Our search retrieved 26,490 records, from which 199 studies were extracted in a masked, duplicate fashion. Each study was evaluated for the nine most-common types of spin and other study design parameters. Spin was presented as frequencies and odds ratios to identify associations between study characteristics.Findings: Spin was identified in the abstracts of 27 systematic reviews (27/199, 13·6%). Spin type 5 was the most common type identified (8/199, 4%). Only one of the nine spin types was not identified. The frequency of spin decreased by 11% each year (odds ratio: 0·89; 95% confidence interval: 0·80-0·99). No other association was identified between the presence of spin and any other study characteristic.Interpretation: Our findings show that spin is present in the abstracts of systematic reviews focused on pharmacologic therapies for type 2 diabetes mellitus. Any amount of spin can lead to the distortion of a reader’s interpretation of the study’s findings. Thus, we provide recommendations with rationale to prevent spin in future systematic reviews.Funding: Oklahoma State University Center for Health Sciences Presidential Mentor-Mentee Research Fellowship GrantDeclaration of Interests: MS is employed by OSUCHS as an academic physician. Clinical trial principal investigator in non-endocrine related studies (COVID). Dr. Vassar reports grants from the National Institute on Alcohol Abuse and Alcoholism, National Institute on Drug Abuse, US Office of Research Integrity, and the Oklahoma Center for the Advancement of Science and Technology during the conduct of the study. No other authors have any conflicts of interests to disclose.Ethics Approval Statement: This study did not involve humans; thus, it did not meet the regulatory definition for human subjects research per the US Code of Federal Regulations and was not subject to institutional review board oversight.