Learning from an epidemiological, population-based study on prescribed medicine use in adults

The aim of this study was to examine changes in the prevalence of use of prescribed medicines in Australian community samples.

In this study, face-to-face interviews were carried out with random, representative samples of South Australian adults, aged ≥15 years. Data on self-reported use of prescribed medicines, most commonly reported categories of prescribed medicines and use of multiple medicines for common body systems were collected. It was not possible to distinguish between medicines prescribed for acute and chronic use.

A total of 3015 respondents were interviewed in 2004 and 3034 in 2008, representing participation rates of 76% and 73%. There was no significant increase in the prevalence of use of ≥1 (46.8% vs 47.3%, p = 0.6) or ≥6 medicines (5.7% vs 5.5%, p = 0.7). In both years, the use of medicines was higher in women (56.7% vs 57.5%). On subgroup analyses, a significant reduction in the use of medicines was observed in respondents aged 15-24 (25.0% vs 18.5%, p = 0.01) and ≥65 years (87.7% vs 82.5%, p = 0.01), whereas use in those aged 35-44 years increased significantly (26.4% vs 33.6%, p = 0.01). The number of cardiovascular system agents (23.1% vs 24.6%, p = 0.20) and psychotropic medicines (9.8% vs 10.6%, p = 0.35) used by respondents remained unchanged while use of respiratory (7.2% vs 5.7%, p = 0.01) and musculoskeletal system medicines (8.7% vs 5.6% p= < 0.001) decreased significantly.

In presenting what we believe is the first Australian population-based study to compare changes in prescribed medicines across the adult age spectrum, we highlight some key questions to ensure the quality use of medicines. Our findings identify a need to discuss de-prescribing, monitor practices to minimise adverse events and challenge if consumers and prescribers need to consider the costs to governments of medicines.