Are People Living With Dementia Receiving High Intensity Statin Therapy After Stroke? A Population-Based Cohort Study

Abstract

Background and aims: This Australian population-based study investigated statin intensity after hospitalization for ischemic stroke in a matched cohort of people living with and without dementia.

Methods: We identified all patients aged ≥ 30 years hospitalized in the state of Victoria, Australia, for ischemic stroke from July 1, 2013 to April 30, 2018 from the Victorian Admitted Episodes Data set. People with dementia were matched 1:4 for sex, 5-year age group and index date ± 90 days with people without dementia. Records of statin dispensing within 60 days postdischarge were extracted from prescription claims data. The intensity of the first postdischarge statin dispensing was determined. Odds ratios for high versus low-moderate intensity and no statin dispensing were estimated using multinomial logistic regression adjusted for factors including age, sex, and comorbidity.

Results: The cohorts comprised 11,105 people (dementia: N = 2221; without dementia: N = 8884 and 52% were female. Compared to people without dementia, people with dementia had 35% (95% confidence interval [CI]: 24%-44%) lower odds of receiving a high intensity versus a low-moderate intensity statin and 54% (95% CI: 48%-59%) lower odds of receiving a high intensity versus no statin. Compared to men, women with and without dementia had 16% (95% CI: 5%-25%) lower odds of receiving a high- versus low-moderate intensity statin and 28% (95% CI: 19%-35%) lower odds of receiving a high intensity versus no statin.

Conclusions: People living with dementia are less likely to receive high-intensity statins post-discharge compared to people without dementia. There is a gender gap in receipt of guideline-recommended high-intensity statin therapy for secondary prevention after ischemic stroke.

Clinical implications: Guidelines recommend all people with reasonable life expectancy receive a high-intensity statin after stroke to reduce the risk of recurrent stroke and other adverse cardiovascular events. More research is needed to understand why people living with dementia might not receive guideline recommended care, and how statin use and statin intensity impact the health outcomes of people living with dementia and stroke.

Keywords: dementia; linked data; statins; stroke.