Potentially inappropriate medications and potential prescribing omissions in hospitalised older adults in New Zealand: A retrospective study

Objective: Medication errors can have detrimental effects on patient outcomes, yet there are limited data on the prevalence of potentially inappropriate medications (PIMs) and potential prescribing omissions (PPOs) among older adult inpatients in New Zealand (NZ). This study investigated exposure to PIMs and PPOs in older adults in a New Zealand hospital.

Methods: Electronic medical records of 846 older adults (≥ 65 years) discharged from the Auckland District Health Board between June 2020 and May 2021 were retrospectively reviewed to extract data on sociodemographic, medication and diagnostic information. STOPP/START version 2 was used to evaluate PIMs and PPOs on admission and discharge.

Results: The mean age was 77.47 ± 8.12 years, and 51% were female. On admission, 48% had ≥1 PIMs and 40% had ≥1 PPOs. On discharge, 45% had ≥1 PIMs and 40% had ≥1 PPOs. Increasing age (adjusted odds ratio [AOR] = 1.02, 95% CI [confidence interval] 1.01, 1.04), number of medicines (AOR = 1.23, CI 1.17, 1.29) and 28-day admission history (AOR = 1.58, CI 1.15, 2.18) were associated with higher odds of PIMs use on admission. At discharge, the number of medicines (AOR = 1.19, CI 1.13, 1.25) and history of readmission (AOR = 1.47, CI 1.08, 2.02) were associated with higher odds of PIMs. Female patients had higher odds of PPOs both on admission (AOR = 1.35, CI 1.02, 1.78) and discharge (AOR = 1.34, CI 1.01, 1.78). Māori, Asian and Pacific patients were more likely to have prescribing omissions compared to NZ Europeans.

Conclusions: Prescribing omissions and inappropriate medications were common in older inpatients. There were differences observed between different ethnic groups, with NZ Europeans having fewer omissions than other ethnic groups. These findings highlight key opportunities for health-care providers to improve medication use in older adults in NZ.