Polypharmacy is increasingly common in the elderly. The medication compliance of polypharmacy is closely related to its therapeutic effect and safety. Therefore, it is of great significance to understand the medication compliance and its influencing factors in the elderly with polypharmacy at early stage. However, the conclusions of current studies vary greatly, and there is no clear and unified standard.

To systematically evaluate the current status of polypharmacy in the elderly and its influencing factors, in order to provide reference for improving medication compliance of polypharmacy in the elderly, reducing adverse reactions, and further developing individualized intervention programs.

PubMed, Embase, Web of Science, Cochrane Library, Scopus, Ovid, CBM, CNKI, Wanfang Data and VIP were searched for cohort studies, case-control studies, cross-sectional studies and other observational studies on the influencing factors of medication compliance of polypharmacy in the elderly from inception to March 2023. Two researchers independently screened the literature, evaluated the quality and extracted the data according to the inclusion and exclusion criteria. Stata 17.0 and RevMan 5.3 software were used for meta-analysis.

A total of 19 studies were included with the total sample size of 130 047 subjects, including 50 852 subjects with good medication compliance. Meta-analysis results showed that the medication compliance rate of polypharmacy in the elderly was 41%〔95%CI (34%, 47%) 〕, which was associated with age〔OR=2.62, 95%CI (1.60, 4.78), P<0.000 1〕, gender〔OR=1.70, 95%CI (1.30, 2.23), P=0.000 1〕, education level〔OR=1.73, 95%CI (1.38, 2.16), P<0.000 01〕, residential lifestyle〔OR=2.85, 95%CI (2.18, 3.72), P<0.000 01〕, medication knowledge level〔OR=1.14, 95%CI (1.04, 1.25), P=0.005〕, medication belief〔OR=2.06, 95%CI (1.44, 2.93), P<0.000 1〕, depression〔OR=2.52, 95%CI (1.96, 3.24), P<0.000 01〕, daily living ability (ADL) 〔OR=2.39, 95%CI (1.68, 3.38), P<0.000 01〕, history of falls〔OR=3.51, 95%CI (2.03, 6.06), P<0.000 01〕, professional guidance 〔OR=3.75, 95%CI (1.92, 7.33), P=0.000 1〕, the number of drug types〔OR=2.58, 95%CI (1.96, 3.41), P<0.000 1〕, adverse drug reactions〔OR=3.08, 95%CI (2.17, 4.38), P<0.000 1〕, medication regimen complexity〔OR=1.08, 95%CI (1.03, 1.14), P=0.004〕, medication management〔OR=1.92, 95%CI (1.34, 2.75), P=0.000 3〕 and medication cost〔OR=2.60, 95%CI (1.30, 5.17), P=0.000 7〕. Sensitivity analysis showed that the results of meta-analysis were relatively stable. Begg's test (P=0.441) and Egger's test (P=0.674) suggested that there was a low risk of publication bias for medication compliance of polypharmacy in the elderly in the included studies.

The compliance rate of polypharmacy in the elderly is 41%. And the available evidence shows that general factors (age, gender, education level, residential lifestyle), psychological and social factors (depression, ADL, history of falls, medication knowledge level, medication belief, professional guidance), drug factors (medication management, medication cost, medication regimen complexity, the number of drug types, adverse drug reactions) are the influencing factors of medication compliance of polypharmacy in the elderly. Medical staff should formulate individualized intervention measures and optimize disease management in the elderly with polypharmacy according to the influencing factors of medication compliance of polypharmacy.