An Epidemiological Survey of Stroke in Lhasa, Tibet, China

Abstract

Background and Purpose— There have not been any new epidemiological studies related to stroke in Tibet for 20 years. This study aimed to collect stroke data from The City Staff Medical Insurance Registry in Lhasa, Tibet, to describe the incidence, clinical subtypes, and associated risk factors of stroke. Methods— We used retrospective, population-based descriptive analysis of all urban and rural workers in the City Staff Medical Insurance Registry who were admitted to designated hospitals from October 2006 to October 2008. Stroke was defined by the International Classification of Disease (ICD)-10 coded from hospital records. Results— Workers (81 298) were listed in the City Staff Medical Insurance Registry. Stroke patients (165) were included in the study, with 133 being first-ever patients. The age-standardized incidence rate was 88.725/100 000 per year (95% CI, 72.228–105.221), and mortality rate was 25.941/100 000 per year (95% CI, 16.416–35.466). The case fatality rate was 21.82%. Seventeen of the 133 patients (12.8%) were <45 years of age. Stroke incidence rate was higher in ethnic Han patients than ethnic Tibetan patients. The most common subtype was cerebral infarction, and the most important risk factor was hypertension. Conclusion— Since the last study 20 years ago in Lhasa, stroke remains the primary fatal disease for the elderly, and its occurrence at younger ages is higher in Lhasa than in other areas of China. However, the annual incidence rate and mortality rate have decreased. The annual incidence rate is at a similar level to that in other parts of China. The primary subtype of stroke in Lhasa is cerebral ischemia.