A 10-Year Trend in Statin Use Among Older Adults in Australia: an Analysis Using National Pharmacy Claims Data

Statins have become standard of care in the prevention and treatment of atherosclerotic cardiovascular disease. The objective of this study was to examine the trends in statin use among Australians aged ≥ 65 years for the period 2007-2016.

Data from the Pharmaceutical Benefits Scheme covering a 10% random sample of the Australian population were analysed. The 1-year prevalence and incidence of statin use were determined for each year, as were the percentage of statin dispensations according to statin type or intensity and the percentage of new users prescribed each statin type or intensity. To describe relative changes, age-sex adjusted rate ratios (RRs) and 95% confidence intervals (CIs) were determined via Poisson regression modelling using 2007 as the reference year.

The 1-year prevalence of statin use increased consistently each year from 34.2% in 2007 to 44.1% in 2016 (RR 1.29, 95% CI 1.28-1.31). The 1-year incidence was 68.5 per 1000 in 2007 and 59.0 per 1000 in 2016 (RR 0.87, 95% CI 0.84-0.90). Women were 18% (age-adjusted rate ratio [aRR] 0.82, 95% CI 0.79-0.83) less likely than men to initiate statins across all years. The incidence of statin use was also highest among individuals aged 65-74 years, who were about 15% (sex-adjusted rate ratio [sRR] 1.15, 95% CI 1.13-1.16) and 45% (sRR 1.45, 95% CI 1.44-1.47) more likely to initiate statins than those aged 75-84 and ≥ 85 years, respectively. Atorvastatin was the most commonly dispensed statin across all years. The proportion of new users dispensed high-intensity statins increased year-on-year from 23.6% in 2007 to 30.5% in 2016 (RR 1.26, 95% CI 1.21-1.31).

The proportion of older adults in Australia using statins has increased over the last decade, although the incidence has declined. Atorvastatin is the most commonly dispensed statin and the use of high intensity statin has increased.