The prevalence and factors associated with potentially inappropriate medication use in Chinese older outpatients with cancer with multimorbidity

Background Multimorbidity and polypharmacy is a general problem in older patients; they increase the prevalence of potentially inappropriate medication (PIM) use. But PIM use in patients with cancer is less clear. This study aimed to examine the prevalence and the predictors of PIM use in Chinese older outpatients with cancer with multimorbidity in Chengdu based on the 2019 Beers Criteria. Methods A cross-sectional study was conducted using electronic medical data from nine tertiary hospitals in Chengdu from January 2018 to December 2018. The 2019 AGS Beers Criteria were used to evaluate the PIM status of older outpatients with cancer (age ≥ 65 years), and multivariate logistic regression was used to identify the risk factors associated with PIM use. Results A total of 6160 cancer outpatient prescriptions were included in the study. The prevalence of PIM use based on the 2019 AGS Beers Criteria was 32.65%. The most frequently used PIMs in outpatients with cancer were benzodiazepines and benzodiazepine receptor agonist hypnotics, diuretics, tramadol, non-steroidal anti-inflammatory drugs, and glimepiride. Logistic regression demonstrated that age ≥ 80 (odds ratio [OR]: 1.238, 95% confidence interval [CI]: 1.071, 1.431, P = 0.004), more diseases (OR: 1.193, 95% CI: 1.017, 1.399, P = 0.03), polypharmacy (OR: 2.520, 95% CI: 2.169, 2.927, P<0.001), and irrational use of drugs (OR: 1.762, 95% CI: 1.408, 2.205, P<0.001) were positively associated with PIM use in older outpatients with cancer. Conclusions The prevalence of PIM use in Chinese older outpatients with cancer and multimorbidity is high in China. The increased prescription complexity caused by cancer will further increase the prevalence of PIM use. Research on interventions rationing PIM use in the older cancer population are necessary in the future.