Association of disability level with polypharmacy and potentially inappropriate medication in community dwelling older people

Abstract

Aims: To investigate the influence of disability severity level on polypharmacy and the prescription of potentially inappropriate medication (PIM) using health insurance and long-term care (LTC) insurance claim data.

Methods: Data were obtained from a health-care insurance and long-term care insurance claims database of citizens of Kure city, Japan, in April 2017. Data including age, sex, and drug profile were obtained, and the level of LTC needs was used to measure disability level. Factors associated with polypharmacy (≥5 prescribed drugs) and PIM prescription (≥1 PIM) defined by STOPP-J were analyzed statistically.

Results: Among 67,169 people aged ≥65 (mean age 77.2 ± 7.9, male 40.7%), the frequency of polypharmacy increased with age until 85-89 (male 58.3%, female 57.6%) in both genders, and polypharmacy was most prevalent in those at the mildest LTC level (support level: male 68.9%, female 73.7%). PIM prescriptions was also frequent in those with LTC needs. On multiple logistic regression analysis, polypharmacy was significantly associated with older age and LTC needs, and PIM prescription was associated with older age and higher LTC level, suggesting that there is a large difference in prescription according to the person's age and disability level.

Conclusion: Polypharmacy was prevalent especially in older persons which peaked at the age of 85-89 or at mild disability level, and PIM prescription was prevalent in those with older age and higher care levels. When optimizing polypharmacy or PIM prescription in older patients, healthcare providers should focus on not only age but also disability level.

Keywords: Dementia; Disability; Long-term care; Polypharmacy; Potentially inappropriate medication.