Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours

We reviewed the existing quality assessment tools for systematic reviews of observational studies and developed a concise quality assessment checklist to help standardise decisions regarding the quality of studies, with careful consideration of issues such as external and internal validity.A pilot version of the checklist was developed based on epidemiological principles, reviews of study designs, and existing checklists for the assessment of observational studies. The Quality Assessment Tool for Systematic Reviews of Observational Studies (QATSO) Score consists of five items: External validity (1 item), reporting (2 items), bias (1 item) and confounding factors (1 item). Expert opinions were sought and it was tested on manuscripts that fulfil the inclusion criteria of a systematic review. Like all assessment scales, QATSO may oversimplify and generalise information yet it is inclusive, simple and practical to use, and allows comparability between papers.A specific tool that allows researchers to appraise and guide study quality of observational studies is developed and can be modified for similar studies in the future.Epidemiological evidence-based research is becoming an increasingly important basis for health care decisions and planning. There is a dearth of reviews of observational and analytic studies on HIV prevalence and risk factors for HIV transmission among men having sex with men (MSM), and this is particularly the case in mainland China [1-3]. We sought to conduct a rigorous systematic review summarising HIV prevalence data in MSM and to measure their associated high risk behaviours in China, with the aim of providing systematic and comprehensive data for policymakers to devise appropriate plans for health promotion and interventions to control the spread of HIV in the target population.A number of consensus statements have previously been prepared to encourage higher quality of reporting, including recommendations for reporting systematic reviews (QUORO