The risk of potentially inappropriate medications (PIMs) use in older outpatients internationally is rising, according to recent findings, suggesting a potential need for reforms in health care and drug safety around the world.¹

These new findings were the results of a study from China conducted given the lack of research on PIM use in an outpatient context as well as the close association between PIM use in elderly adults and increases in emergency department visits and adverse drug events.²

The research was authored by Fangyuan Tian, from Sichuan University West China Hospital’s Department of Pharmacy in China, and the investigators note that the base of outpatients is larger than that of inpatients. They added that outpatients’ medication range is more complex than the range among those in primary care.

“In the current study, we sought to conduct a systematic review with meta-analysis to estimate the overall prevalence of PIM use among older patients in outpatient services,” Tian and colleagues wrote.

Background and Findings

The investigators conducted a systematic review and meta-analysis, with the inclusion criteria for the studies used in the analysis including the following:

• Older outpatient recruitment aged ≥60 years with prior visits to outpatient departments
• Reporting of the point prevalence of PIM use being based upon explicit PIM criteria
• Provision of statistical information or raw data on the outcomes

Studies were excluded by the investigators if they recruited individuals from sources outside of outpatient services, such as nursing homes. They were also excluded if they did not assess use of PIMs based upon published explicit PIM criteria or if they had only an article on PIM with a country.

The research team followed the Preferred Reporting Items for Systematic Review and Meta-analysis checklist and created literature searches from January of 1990 to November of 2022, using specified search terms in Embase, PubMed, and Web of Science. Data extraction included PIM criteria, basic study characteristics, prevalence of PIM use, and assessments of quality.

The research team’s analysis gathered information on some basic study characteristics such as the country, authors, sample period, publication years, study design, age of definition of older adults, mean number of drugs (with polypharmacy being defined as >5 drugs), sample size, proportion of male participants, and population.

The team’s analysis also included details about PIMs criteria, the number of patients using 1 or more PIMs, and the reported prevalence of PIM use by the participants. Both sensitivity analyses and publication bias tests were also used by the investigators.

Overall, the investigators found a total of 1640 studies for their analysis, and after exclusion, 94 studies with 371,224,692 older outpatients were decided upon as those which would be included. These various studies had been conducted across 17 countries, with most studies having been conducted in Asia.

In the time between 1999 - 2021, the majority of studies had been completed in countries labeled high-income. The research team found that prevalence of use of PIMs among older outpatients varied substantially, ranging from 1.3% - 95.2%, with benzodiazepines noted as the most frequently-used drugs labeled as PIMs.

In their meta-analysis, the investigators also reported that the pooled prevalence of PIM use was estimated at 36.7% across all included studies. The prevalence of PIMs was also found to be higher in both Africa and South America, and lower in Oceania and North America.

The prevalence of PIM use varied by various criteria: design of study, location, number of drugs, age, and other factors among the studies.

“Overall, PIM use was found to occur among nearly 37% of older outpatients, with an increasing trend in the last 2 decades and an even higher prevalence in some low-income countries,” they wrote. “The high prevalence of PIM use highlights the global need for health care reforms and improvements in drug safety in outpatient settings.”

The team added that their medical conditions in Africa are not as favorable as those in other regions, and the lack of specific PIM criteria for older people in the region, unlike other areas, could be an element contributing to the prevalence of PIM use in the continent.

References

1. ^{Tian F, Chen Z, Zeng Y, Feng Q, Chen X. Prevalence of Use of Potentially Inappropriate Medications Among Older Adults Worldwide: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2023;6(8):e2326910. doi:10.1001/jamanetworkopen.2023.26910.}
2. ^{Su S, Gao L, Ma W, et al. Number-dependent association of potentially inappropriate medications with clinical outcomes and expenditures among community-dwelling older adults: a population-based cohort study. Br J Clin Pharmacol. 2022;88(7):3378-3391. doi:10.1111/bcp.15286.}