Incidence and prevalence of stroke and time trends in vascular risk factors among urban/semi-urban Sri Lankans: A population-based cohort study

Abstract

INTRODUCTION AND OBJECTIVES: Incidence of stroke is declining in developed countries, but is increasing in developing countries. There is no data on incidence of stroke in Sri Lanka, and only limited data on prevalence of stroke. METHODS: We studied a population-based cohort (35-64 years) selected by stratified random sampling from an urban/semi-urban health administrative area (Ragama Health Study) in 2007, and evaluated them again in 2014 with regard to new onset stroke and prevalence of vascular risk factors. Possible stroke patients were independently reviewed by a neurologist and a physician with regard to the diagnosis of stroke. The prevalence of stroke (at baseline) was estimated. Prevalence of vascular risk factors in the population were compared between 2007 and 2014. RESULTS: The baseline cohort in 2007 consisted of 2985 individuals (females 54.5%, mean age 52.4 ± 7.8 years). Of them, 2204 attended follow-up in 2014 (female 57.6%, mean age 59.2±7.6 years). 19 had a history of strokes at enrolment (stroke prevalence 6.37/1000 population) and 24 episodes of strokes occurred over the 7 years (annual incidence of stroke 1.56/1000 population). Risk factor prevalence in 2007 and 2014 were; hypertension 48.7% and 64.3%; hyperlipidaemia 35.5% and 39.3%; diabetes mellitus 28.2% and 35.7%; and obesity 2.6% and 17.9%, respectively. CONCLUSION: Stroke incidence and prevalence rates of Sri Lanka lie between those of developed and developing countries. Prevalence of vascular risks have increased over time in this urban/semi­ urban Sri Lankan population.