Importance: The use of potentially inappropriate medications (PIMs) is widespread yet continues to receive little attention in outpatient services.
Objective: To estimate the overall prevalence of PIM use in outpatient services.
Data sources: PubMed, Embase, and Web of Science were searched to identify relevant studies published from January 1, 1990, to November 21, 2022.
Study selection: Observational studies that reported the prevalence of PIM use among older patients in outpatient services were screened.
Data extraction and synthesis: Two reviewers independently selected eligible articles, extracted data, and assessed the risk of bias. A random-effects meta-analysis was conducted to pool the prevalence estimates.
Main outcomes and measures: The global patterns in the prevalence of PIM use among older patients in outpatient services were estimated, and the temporal trends and regional differences in PIM use were investigated.
Results: A total of 94 articles with 132 prevalence estimates were analyzed, including nearly 371.2 million older participants from 17 countries. Overall, the pooled prevalence of PIM use was 36.7% (95% CI, 33.4%-40.0%). Africa had the highest prevalence of PIM use (47.0%; 95% CI, 34.7%-59.4%), followed by South America (46.9%; 95% CI, 35.1%-58.9%), Asia (37.2%; 95% CI, 32.4%-42.2%), Europe (35.0%; 95% CI, 28.5%-41.8%), North America (29.0%; 95% CI, 22.1%-36.3%), and Oceania (23.6%; 95% CI, 18.8%-28.8%). In addition, the prevalence of PIM use is highest in low-income areas. Use of PIMs among older patients has become increasingly prevalent in the past 2 decades.
Conclusions and relevance: This study of patterns of PIM use by different groups, such as geographic regions and World Bank countries, suggests noticeable geographic environment and economic income differences in the burden of PIMs in outpatient services. Furthermore, the high prevalence trend in the past 2 decades indicates that the global burden of PIM use continues to be worthy of attention.