Background: Hypertension is one of the top contributors to the global disease burden. Identifying effective interventions for hypertension is a major global public health challenge. Evidence from systematic reviews (SR) is of great importance for the management of hypertension. Methodological quality of meta-analysis on hypertension treatments can affect treatment decisions.
Objectives: To investigate the methodological quality of meta-analyses of hypertension treatments.
Methods: We searched the Cochrane Database of Systematic Reviews and the Database of Abstracts of Reviews of Effect. SRs with at least one meta-analysis on hypertension treatment effect were considered eligible. We assessed methodological quality with the validated Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool.
Results: We identified 158 meta-analyses on hypertension treatments, with 32 (20.3%) being Cochrane meta-analyses and 16 (10.1%) being an update of a previous meta-analysis. Overall, methodological quality was unsatisfactory in the following aspects: comprehensive reporting of the sources of support (1.9%), provision of included and excluded list of studies (22.8%), inclusion of grey literature (27.2%), and inclusion of protocols (32.9%). The 126 non-Cochrane meta-analyses had poor performance on almost all the methodological items except for providing characteristics (63.5%) and assessing the scientific quality (61.1%) of included studies. Among non-Cochrane meta-analyses, those that focused on non-pharmacological treatments were more likely to consider the scientific quality of included studies when drawing conclusions; meta-analyses published recently were better at using appropriate statistical methods and assessing publication bias. The 32 Cochrane meta-analyses generally had good methodological quality except for comprehensive reporting of the sources of support.
Conclusions: Our results highlight the need for cautious interpretation of these meta-analyses, especially among physicians and policy-makers when guidelines are formulated. Future meta-analyses should address the shortcomings in these methodological items.