Evaluation of spin in the abstracts of systematic reviews and meta-analyses related to the treatment of proximal humerus fractures

Abstract Background Research has shown that many physicians rely solely on abstracts to make clinical decisions. However, many abstracts have been shown to be misleading. The primary objective of this study was to identify the prevalence of spin — bias towards particular results — within the abstracts of systematic reviews and meta-analyses pertaining to the treatment of proximal humerus fractures, one of the most common osteoporotic fractures among elderly patients. Methods We systematically searched MEDLINE and Embase databases to identify systematic reviews and meta-analyses examining the treatment of proximal humerus fractures. Screening and data extraction occurred in a masked, duplicate fashion. The nine most severe types of spin that occur within abstracts were extracted along with study characteristics, including journal recommendations to adhere to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and year in which the review was performed, to identify potential associations. We subsequently explored the association between spin and the methodological quality of a systematic review using the revised A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) appraisal instrument. Results Our search retrieved 505 articles, of which 73 systematic reviews met inclusion criteria. We found that 34.2% (25/73) of the included systematic reviews contained spin. Spin type 3 (selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention) was the most common type identified (12/73, 16.4%). Three spin types were not identified in any of the abstracts. Spin was 3.2 (OR 3.2; 95% CI, 1.02-10.02) times more likely to be present in systematic reviews published in journals recommending adherence to PRISMA. Furthermore, the odds of an abstract containing spin was 1.25 (OR 1.25; 95% CI, 1.02-1.52) times more likely to be present in systematic reviews for each year after 2000. No other study characteristics were associated with spin. The methodological quality of 24 studies were rated as “critically low” (32.9%), 14 were “low” (19.2%), 28 were “moderate” (38.4%), and 7 were “high” (9.6%), but these findings were not associated with spin. Conclusion Spin was present in systematic review abstracts regarding treatment of proximal humerus fractures. Measures such as education on the subject of spin and improved reporting standards should be implemented to increase awareness and reduce incidence of spin in abstracts. Level of evidence of the study performed Basic Science Study; Research Methodology