Predictors of statin use among older adults: A nationwide cross-sectional study

Abstract

Background: Statins comprise a key strategy for the prevention and treatment of arteriosclerotic cardiovascular disease, but prescribing remains suboptimal.

Objectives: The objective of this study was to characterize the predictors of statin use among adults aged ≥65 years.

Methods: A cross-sectional study using Pharmaceutical Benefits Scheme (PBS) data on reimbursed prescriptions for a 10% random sample of the Australian population in 2016 was performed. Predictors of statin use were identified via multivariable logistic regression. Analyses were performed separately for people who were concessional beneficiaries (with a low, capped copayment) and other ("general") people.

Results: Among 351,471 (concessional = 295,875 and general = 55,596) older adults, 44.2% were dispensed statins (concessional = 46.4% and general = 32.2%). Among the concessional beneficiaries, people aged 75 to 84 years were more likely to use statins (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.06-1.10), whereas those aged ≥85 years were less likely to use statins (OR 0.71, 95% CI 0.69-0.72), compared with people aged 65 to 74 years. Men were more likely to use statins than women (OR 1.14, 95% CI 1.12-1.16). Diabetes was associated with over 2-fold (OR 2.48, 95% CI 2.43-2.53) increased likelihood of statin use. People with cardiovascular-related conditions including hypertension, angina, and congestive heart failure experienced increased likelihood of statin use as was being dispensed anticoagulant or antiplatelet medication. Having malignancy, psychotic illness, or pain were associated with lower likelihood of statin use. Similar predictors of statin use were noted for the general population.

Conclusion: More than 40% of older adults in Australia used statins in 2016 with uptake dependent on individual-level factors such as demographics and comorbidities. Future research should examine the extent to which provider and/or health system-level factors contribute to the variable uptake of statin therapy.

Keywords: Cholesterol treatment; HMG-CoA reductase inhibitors; Older adults; Predictors; Prescribing.