Reporting Bias in Systematic Reviews and Meta-Analyses of Primary ACL Repair.

PURPOSE:The purpose of this study is to analyze reporting bias in the form of spin present in systematic reviews and meta-analyses on the topic of primary anterior cruciate ligament (ACL) repair. METHODS:Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed throughout this study. Peer-reviewed systematic reviews were collected from 3 databases (PubMed, Scopus, and SPORTDiscus) and their abstracts were assessed for the 15 most common types of spin. Articles were excluded if not published in English, had no evidence, were retracted, were published without an abstract, did not have full text available, or included cadaver or nonhuman subjects. Full text quality was assessed using A Measurement Tool to Assess Systematic Reviews Version 2 (AMSTAR 2). Fisher's exact tests were used to examine associations between the different types of spin and other study characteristics such as AMSTAR 2 confidence rating, study design, and level of evidence. RESULTS:Spin was present in the abstracts 13 of 15 (86.7%) articles. There were significant associations between PRISMA adherence and lower incidences of spin types 3, 6, and 8 (p=0.029 each). A critically low AMSTAR 2 confidence rating was significantly associated with increased incidence of spin type 9 (p = 0.01), and a higher AMSTAR 2 score was significantly associated with decreased spin type 4 and 5 (p=0.039 and 0.048, respectively). More recent year of publication was correlated with a lower incidence of spin type 14 (p=0.044). CONCLUSION:Spin is present in the majority of systematic reviews and meta-analyses regarding primary repair of the ACL, with two-thirds of abstracts spinning evidence in favor of ACL repair. Standardized guidelines including PRISMA and the AMSTAR 2 assessment tool were negatively correlated with spin. More recently published articles were found to contain significantly less spin, along with articles published in journals with higher Clarivate Impact Factors and Scopus CiteScores.