ABSTRACT Background Pharmacogenetic testing offers a pathway to safer prescribing and improved outcomes in older adults, who face heightened risks of adverse drug reactions due to polypharmacy and age‐related metabolic changes. This study evaluates the prevalence of actionable pharmacogenetic biomarker use and estimates the potential impact of genotype‐guided dosing in Chinese older adults. Methods This retrospective cross‐sectional analysis utilized 2015–2017 claims data from the China Health Insurance Research Association (CHIRA), encompassing 3,309,025 older patients (≥ 65 years) and 74,415,484 prescriptions. Drugs with Clinical Pharmacogenomics Implementation Consortium (CPIC) Level A evidence for actionable pharmacogenetic variants ( n = 53) were identified. Key measures included the prescribing prevalence of Level A drugs and projected rates of actionable phenotype‐driven dosing changes, calculated using population‐specific genotype frequencies from PharmGKB and published sources. Results Among older adults, 43.4% (433.8 per 1000) were prescribed ≥ 1 CPIC Level A drug. Atorvastatin (131.1 per 1000), omeprazole (124.3 per 1000), and clopidogrel (75.7 per 1000) were the most common. Over one‐third (36.5%; 365.3 per 1000) of exposures required genotype‐guided dose adjustments, with clopidogrel (CYP2C19) and statins (SLCO1B1) representing the highest‐priority gene‐drug interactions (259.6 and 221.8 per 1000, respectively). Conclusions CPIC Level A pharmacogenetic biomarkers are prevalent in Chinese older adults, with over 40% exposed to actionable gene‐drug pairs and 36.5% requiring dose adjustments. These findings highlight the clinical imperative to integrate pharmacogenetic testing into geriatric care, prioritize CYP2C19 and SLCO1B1 testing, and develop region‐specific guidelines to mitigate polypharmacy risks. Policymakers and clinicians should consider targeted implementation strategies to optimize prescribing safety and efficacy in aging populations.
Zhao et al. (Mon,) studied this question.