Background: Carefully conducted systematic reviews can provide reliable evidence on the effectiveness of treatment strategies for Alzheimer’s disease. Nevertheless, the reliability of systematic review results can be limited by methodological flaws. This study aims to appraise methodological quality of systematic reviews on Alzheimer’s disease treatments and explore factors associated with the quality.
Objectives:
Methods: Four international databases, including MEDLINE, EMBASE, PsycINFO, and Cochrane Database of Systematic Reviews, were searched for systematic reviews on Alzheimer’s disease treatments. The methodological quality of included studies was appraised using the Assessing the Methodological Quality of Systematic Reviews 2 instrument. Factors associated with methodological quality were investigated using multivariate regression analyses.
Results: A total of 102 systematic reviews are appraised. Four (3.90%) systematic reviews are considered as high quality, and fourteen (13.7%), forty-eight (47.1%), thirty-six (35.3%) are of moderate, low, and critically low quality, respectively. Key methodological limitations are as follows: only 22.5% of systematic reviews registered protocols a priori, 6.9% explained rationales of selected study designs, 21.6% provided a list of excluded studies with justifications, and 23.5% reported funding sources of primary studies. Cochrane reviews (adjusted odds ratio [AOR]: 31.9, 95% confidence interval [CI]: 3.81-266.9) and systematic reviews of pharmacological treatments (AOR: 3.96, 95% CI: 1.27-12.3) are associated with higher overall methodological quality of systematic reviews.
Conclusions: Methodological quality of systematic reviews on Alzheimer’s disease treatments is unsatisfactory, especially among non-Cochrane reviews and systematic reviews of nonpharmacological interventions. Improvement in the following methodological domains requires particular attention due to poor performance: registering protocols a priori, justifying study design selection, providing a list of excluded studies, and reporting funding sources of primary studies. Patient, public, and/or healthcare consumer involvement: NA.