Clinical Epidemiology (Jun 2019)
Statin use and high-dose statin use after ischemic stroke in the UK: a retrospective cohort study
Abstract
Zhirong Yang,1 Duncan Edwards,1 Efthalia Massou,1 Catherine L Saunders,1 Carol Brayne,2 Jonathan Mant11Primary Care Unit, Department of Public Health and Primary Care, School of Clinical Medicine, University of Cambridge, Cambridge, UK; 2Institute of Public Health, School of Clinical Medicine, University of Cambridge, Cambridge, UKBackground: Trial evidence supports statin use after ischemic stroke and recent American, European and British guidelines recommend high-intensity statins for this indication. Limited data are available describing current statin use among these patients in unselected settings. We conducted a cohort study to examine secular trends and factors associated with statin use and dose following ischemic stroke.Methods: A retrospective cohort study of patients with first ischemic stroke between 2000 and 2014 was conducted using the Clinical Practice Research Datalink (CPRD). Proportions of statin users and high-intensity statin users within 2 years after stroke were estimated for each calendar year. We used Cox regression models to explore potential factors associated with statin use and Poisson regression models to calculate risk ratios for the use of a high-intensity statin.Results: A total of 80,442 patients with first stroke were analyzed. The proportion using statins within 2 years after stroke increased from 25% in 2000 to 70% in 2006 and remained at about 75% through 2014. Among post-stroke statin users, high-intensity use accounted for approximately 15% between 2004 and 2011 and then increased to almost 35% in 2014. Older patients (aged ≥75 years), younger patients (<45 years), patients with no prior statin treatment, dementia, underweight, or absence of cardiovascular factors (coronary heart disease, smoking, obesity, diabetes, hypertension, or transient ischemic attack) were less likely to use statins and less likely to receive a high-intensity statin.Conclusion: There has been an increase over time in both statin use and dose, but many patients with ischemic stroke continue to be under-treated. Clinical trials and policy interventions to improve appropriate post-stroke statin use should focus on younger and older patients, patients with no pre-stroke statin treatment, and patients without additional cardiovascular risk factors.Keywords: cerebral ischemia, lipid-lowering, trend, factors