Warwick Centre for Applied Health Research and Delivery, University of Warwick, Coventry, England, United Kingdom.
Health Services Management Centre, University of Birmingham, Birmingham, England, United Kingdom.
PLoS One. 2020 Jan 30;15(1):e0227580. doi: 10.1371/journal.pone.0227580. eCollection 2020.
Strategies to identify and mitigate publication bias and outcome reporting bias are frequently adopted in systematic reviews of clinical interventions but it is not clear how often these are applied in systematic reviews relating to quantitative health services and delivery research (HSDR). We examined whether these biases are mentioned and/or otherwise assessed in HSDR systematic reviews, and evaluated associating factors to inform future practice. We randomly selected 200 quantitative HSDR systematic reviews published in the English language from 2007-2017 from the Health Systems Evidence database (www.healthsystemsevidence.org). We extracted data on factors that may influence whether or not authors mention and/or assess publication bias or outcome reporting bias. We found that 43% (n = 85) of the reviews mentioned publication bias and 10% (n = 19) formally assessed it. Outcome reporting bias was mentioned and assessed in 17% (n = 34) of all the systematic reviews. Insufficient number of studies, heterogeneity and lack of pre-registered protocols were the most commonly reported impediments to assessing the biases. In multivariable logistic regression models, both mentioning and formal assessment of publication bias were associated with: inclusion of a meta-analysis; being a review of intervention rather than association studies; higher journal impact factor, and; reporting the use of systematic review guidelines. Assessment of outcome reporting bias was associated with: being an intervention review; authors reporting the use of Grading of Recommendations, Assessment, Development and Evaluations (GRADE), and; inclusion of only controlled trials. Publication bias and outcome reporting bias are infrequently assessed in HSDR systematic reviews. This may reflect the inherent heterogeneity of HSDR evidence and different methodological approaches to synthesising the evidence, lack of awareness of such biases, limits of current tools and lack of pre-registered study protocols for assessing such biases. Strategies to help raise awareness of the biases, and methods to minimise their occurrence and mitigate their impacts on HSDR systematic reviews, are needed.
在临床干预的系统评价中，经常采用识别和减轻发表偏倚和结果报告偏倚的策略，但尚不清楚这些策略在与定量健康服务和提供研究（HSDR）相关的系统评价中应用的频率。我们检查了这些偏倚是否在 HSDR 系统评价中被提及和/或进行了评估，并评估了相关因素以指导未来的实践。我们从 Health Systems Evidence 数据库（www.healthsystemsevidence.org）中随机选择了 2007 年至 2017 年间发表的 200 篇定量 HSDR 系统评价。我们提取了可能影响作者是否提及和/或评估发表偏倚或结果报告偏倚的因素的数据。我们发现，43%（n=85）的综述提到了发表偏倚，10%（n=19）的综述正式评估了发表偏倚。17%（n=34）的系统综述都提到并评估了结果报告偏倚。评估偏倚的最常见障碍是研究数量不足、异质性和缺乏预先注册的方案。在多变量逻辑回归模型中，发表偏倚的提及和正式评估都与以下因素有关：纳入荟萃分析；是干预研究而非关联研究的综述；更高的期刊影响因子；以及报告使用系统评价指南。结果报告偏倚的评估与：是干预研究；作者报告使用推荐评估、发展和评估分级（GRADE）；以及仅纳入对照试验有关。HSDR 系统评价中很少评估发表偏倚和结果报告偏倚。这可能反映了 HSDR 证据的固有异质性以及综合证据的不同方法学方法、对这些偏倚缺乏认识、当前工具的局限性以及缺乏预先注册的研究方案来评估这些偏倚。需要采取策略来提高对这些偏倚的认识，并制定方法来尽量减少它们对 HSDR 系统评价的影响。
