Long-Term Trends in Ischemic Stroke Incidence and Risk Factors: Perspectives from an Asian Stroke Registry

Risk factors of acute ischemic stroke (AIS) are well-recognised, but the relative importance of each contributing risk factor has evolved. Analysing the regional trends of these cardiovascular risk factors will enable the development of more targeted strategies to tackle AIS and reduce morbidity and disability. Few studies have evaluated inter-ethnic risk factor trends within a single co-localised population, especially amongst Asians, who have a different risk factor profile and consequently, stroke mechanisms. Singapore is uniquely placed to contribute to the understanding of these trends, given our multi-ethnic population (Supplementary Table 1). The Singapore Stroke Registry (SSR) is an active nationwide prospective registry collecting data of stroke cases from all public hospitals in Singapore. Our study explored the interethnic trends of incidence and risk factors of AIS cases over a 12-year period using the SSR. These findings can be applied to the development of targeted strategies for the prevention of AIS both locally and regionally. A total of 60,325 AIS cases from 2005 to 2016 were analysed in 3-year quartiles with direct age standardisation using the 2005 to 2007 Singapore resident population as reference. Data was stratified into ethnic groups based on the Singapore Census classification: Chinese, Malay, Indian, or others: which comprises multiple different ethnic groups, a tiny proportion of the population, and thus were not analysed separately. Prevalence of risk factors amongst AIS cases was analysed within each time-period for each subgroup. Trends were analysed using Poisson, logistic, linear, or Cox regression, depending on the specific variables analysed. There was a 11.6% decrease in the age-standardised incidence rate (ASIR) of AIS from 2005–2007 to 2014–2016 (Table 1). The decrease in ASIR was observed in both sexes (males 5.9%; females 19.1%). Stratifying by ethnic group, the ASIR had decreased in both Chinese (15.0%) and Indians (11.2%), but increased by 11.5% in Malays, and specifically, by 20.2% in Malay males. Amongst ≥65-year-old cases, the crude incidence rate Long-Term Trends in Ischemic Stroke Incidence and Risk Factors: Perspectives from an Asian Stroke Registry