Appraisal of the Presence of Spin in Abstracts of Systematic Reviews and Meta-analyses Regarding Free Bone Block Procedures for Glenohumeral Instability

Background: Clinicians increasingly rely on abstracts to assist with clinical decision-making. Spin is a bias that misrepresents research findings. The presence of spin in abstracts may mislead surgeons to believe a treatment is more effective than data suggest. Purpose: To evaluate the presence of spin in abstracts of systematic reviews and meta-analyses on free bone block (FBB) procedures for glenohumeral instability. Study Design: Systematic review; Level of evidence, 4. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Scopus, and Web of Science databases were queried with the terms “bone block” and “shoulder.” Studies were included if they met the following criteria: systematic reviews and/or meta-analyses regarding FBB procedures published in the English language in peer-reviewed journals. Abstracts were analyzed for 15 spin types. Study quality was assessed using AMSTAR 2 (Assessing the Methodological Quality of Systematic Reviews Version 2) categories. Study characteristics including year of publication, journal impact factor and CiteScore, and level of evidence were collected, and Fisher exact test was used to find correlations between spin and study characteristics. Statistical significance was defined as a P value ≤.05. Results: A total of 23 studies were included in this study. Spin was identified in 21 (91.3%) studies, and the number of spin types present in a single study ranged from 0 to 7. Spin type 6 (selective reporting of or overemphasis on harm outcomes or analysis favoring the safety of the experimental intervention) was identified most frequently (17; 73.9%). A significant association was found between spin type 5 (the conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies) and scientific journal ( P = .013), and between spin 9 (the conclusion claims the beneficial effect of the experimental treatment despite reporting bias) and year of publication ( P = .010). Conclusion: Spin is highly prevalent in abstracts of systematic reviews and meta-analyses investigating FBB for glenohumeral instability. Associations between spin and both year and journal of publication were identified. These results suggest that surgeons should use full texts to help inform conclusions when using systematic reviews and meta-analyses to determine the efficacy and safety of FBB for glenohumeral instability.