Impact of Australian home medicines reviews on continuous polypharmacy and associated costs among older women: a cohort study

Introduction: Medication misadventure is associated with the use of polypharmacy and is highly prevalent in the older population living in the community, especially among women. 

Aim: This study aimed to determine the impact of Home Medicines Reviews (HMRs) on continuous polypharmacy, the prevalence of continuous polypharmacy, and inflation-adjusted differences in costs among women who did and did not receive HMRs. 

Method: The study included 9347 participants from the Australian Longitudinal Study on Women’s Health who fulfilled the eligibility criteria from 77–82 years in 2003 to 91–96 years in 2017. Generalised estimating equations were used to estimate the association between HMRs and continuous polypharmacy. Out-of-pocket costs and benefits paid to government were presented as median costs for each participant from 2003 to 2017, alongside interquartile ranges. 

Results: Only a small percentage of women received HMRs in 2003 (1.14%) but this percentage increased over time to 2017 (3.95%). The prevalence of continuous polypharmacy in 2017 was 39.06% amongst women who received an HMR and 28.05% amongst women who did not receive an HMR. There was evidence for an association between the use of HMRs and continuous polypharmacy in the following calendar year (OR 1.12; 95% CI 1.03, 1.21). There was an increase in out-of-pocket (OOP) medication costs in both women with and without HMRs, with the HMR group demonstrating higher OOP medication costs (AUD$26 to AUD$57) than the non-HMR group (AUD$22 to AUD$50). 

Conclusion: HMRs were associated with a modest increase in the odds of continuous polypharmacy in the subsequent year. Increase in OOP medication costs over time highlights the need to further optimise cost-effective medications for individuals.