Get access

Are older Western Australians exposed to potentially inappropriate medications according to the Beers Criteria? A 13-year prevalence study




To examine time trends and factors associated with exposure to potentially inappropriate medications (PIMs) by the Beers Criteria.


PIM consumption days accumulated from the pharmaceutical claims of 251 305 Western Australians aged 65 years (1993–2005) and person follow-up times produced counts/rates. Logistic/Poisson regression generated odds/rate ratios.


A total of 187 616 participants (74.7%) took 1 PIM (1993–2005), the cohort consuming 109 415 PIM daily doses/1000 person-years. Annual exposure decreased from 45–47% to 40%, and annual consumption rate declined from 117 836 to 90 364 daily doses/1000 person-years. Temazepam had the highest exposures (>17 000 daily doses/1000 person-years). Number of medications taken (OR 35.03; 95% CI 34.37–35.71 for 10 vs. 0–2 drugs), annual drug intake (2.08; 2.04–2.12 for highest vs. lowest quartile), and high-level residential aged care (1.96; 1.91–2.01) were most predictive of PIM exposure.


PIM exposure remains high in older Western Australians. Our findings identify patients most at risk and medications to consider on Australia-specific PIM lists.