In the scientific literature, spin refers to reporting practices that distort the interpretation of results and mislead readers so that results are viewed in a more favourable light. The presence of spin in biomedical research can negatively impact the development of further studies, clinical practice, and health policies. This systematic review aims to explore the nature and prevalence of spin in the biomedical literature. We searched MEDLINE, PreMEDLINE, Embase, Scopus, and hand searched reference lists for all reports that included the measurement of spin in the biomedical literature for at least 1 outcome. Two independent coders extracted data on the characteristics of reports and their included studies and all spin-related outcomes. Results were grouped inductively into themes by spin-related outcome and are presented as a narrative synthesis. We used meta-analyses to analyse the association of spin with industry sponsorship of research. We included 35 reports, which investigated spin in clinical trials, observational studies, diagnostic accuracy studies, systematic reviews, and meta-analyses. The nature of spin varied according to study design. The highest (but also greatest) variability in the prevalence of spin was present in trials. Some of the common practices used to spin results included detracting from statistically nonsignificant results and inappropriately using causal language. Source of funding was hypothesised by a few authors to be a factor associated with spin; however, results were inconclusive, possibly due to the heterogeneity of the included papers. Further research is needed to assess the impact of spin on readers’ decision-making. Editors and peer reviewers should be familiar with the prevalence and manifestations of spin in their area of research in order to ensure accurate interpretation and dissemination of research.

在科学文献中，旋转是指报告实践，它们扭曲了对结果的解释并误导了读者，从而使人们从更有利的角度看待结果。生物医学研究中自旋的存在可能对进一步研究，临床实践和健康政策的发展产生负面影响。本系统综述旨在探讨生物医学文献中自旋的性质和普遍性。我们搜索了MEDLINE，PreMEDLINE，Embase，Scopus，并手工搜索了参考列表以查找所有报告，其中包括生物医学文献中至少1个结果的自旋测量。两名独立的编码人员提取了有关报告特征及其包括的研究和所有与自旋相关的结果的数据。结果与自旋相关的结果归纳为主题，并以叙述性综合形式呈现。我们使用荟萃分析来分析自旋与行业研究赞助的关联。我们纳入了35份报告，这些报告调查了临床试验，观察性研究，诊断准确性研究，系统评价和荟萃分析中的自旋。自旋的性质根据研究设计而变化。在试验中，自旋患病率的变化最大（但也最大）。用来旋转结果的一些常见做法包括减少统计上不重要的结果以及不恰当地使用因果语言。一些作者假设资金的来源是与自旋有关的一个因素。但是，结果不确定，可能是由于所包含论文的异质性。需要进一步的研究来评估旋转对读者决策的影响。