Moderate to high prevalence of spin revealed in abstracts and main texts of medical publications: a systematic review of research-on-research studies

OBJECTIVES: To assess the prevalence of spin in medical publications across different study designs and disciplines and to identify related factors for spin, through a systematic review of research-on-research studies (RoRSs). STUDY DESIGN AND SETTING: We searched PubMed, EMBASE, and SCOPUS on May 10, 2021 and updated the searching on March 19, 2025 for RoRSs examining spin in any types of primary studies (eg, randomized controlled trials [RCTs], non-RCTs, systematic reviews [SRs], and observational studies) in any field of medicine. Meta-analyses were used to evaluate the prevalence of spin in titles, abstracts, and main texts and to analyze related factors for spin. RESULTS: = 0%). CONCLUSION: Spin is moderately to highly prevalent in abstracts and main texts of RCTs and SRs in medicine but rare in titles. The high prevalence of spin may cause misinformed clinical decision-making and highlights the need for improving reporting standards in medical publications. PLAIN LANGUAGE SUMMARY: Medical research should report results clearly and honestly so that clinicians, researchers, policymakers, and patients can make informed decisions. However, some studies use "spin" in reporting, meaning that results are presented in a way that makes findings seem more positive or important than they truly are. This can mislead readers and may influence clinical decisions, potentially affecting the treatments and care that patients receive. In the present study, we reviewed previous research that assessed how often spin appears in medical publications. We analyzed 133 studies that assessed spin in different types of research, such as randomized controlled trials and systematic reviews, across a wide range of medical fields. We found that spin was rare in titles of medical publications but common in abstracts and main texts. Around half to two-thirds of abstracts and main texts contained some forms of spin. We also identified several factors that are associated with presence of spin, such as methodological quality of the publications, authors` academic experience, number of authors, study design, and journal characteristics. These findings showed that misleading reporting is common in medical research. Increasing awareness of spin and improving reporting standards and editorial policies may help reduce spin and improve the clarity and reliability of published evidence in medical publications.