GeographicalDifference, Rural-urban Transition and Trend in Stroke Prevalence in China: Findings from a National Epidemiological Survey of Stroke in China (original) (raw)

Accurate and up-to-date provincial and regional-level stroke prevalence estimates are important for research planning and targeted strategies for stroke prevention and management. However, recent and comprehensive evaluation is lacking over the past 30 years in China. This study aimed to examine the geographical variations in stroke prevalence based on data from the National Epidemiological Survey of Stroke in China (NESS-China) and demonstrate urban-rural transition and trend over three decades. The stroke prevalence (prevalence day, August 31, 2013) was estimated using the world standard population. The stroke prevalence was 873.4 per 100,000 population, and varied from 218.0 in Sichuan to 1768.9 in Heilongjiang. Stroke prevalence exhibited a noticeable north-south gradient (1097.1, 917.7, and 619.4 in the north, middle, and the south, respectively; P < 0.001) and showed a 2.0-fold, 1.5-fold, and 1.2-fold increase in rural areas in the north, the middle, and the south, respectively, from 1985 to 2013. Overall, stroke prevalence was higher in the rural regions than in the urban (945.4 versus 797.5, P < 0.001) regions. However, the converse was depicted in 12 provinces. A noticeable geographical variation in stroke prevalence was observed and was evolving overtime in China. It is imperative that effective public health policies and interventions be implemented, especially in those regions with higher prevalence. Stroke is the second leading cause of death and the third leading cause of disability-standardized life-years lost globally 1. It is estimated that over two-thirds of stroke deaths worldwide occur in developing countries 2. In China, stroke burden has increased over the past 30 years, in both the rural and urban population, with 2.4 million new strokes and 1.1million stroke-related deaths each year; presently, there are over 11.1 million stroke survivors 3. Some studies 1,2,4,5 have reported substantial geographic variations in the distribution of stroke globally. The differences exist not only between countries but also between regions within a country. High-stroke incidence, mortality, and morbidity were identified in Eastern Europe, Eastern and Southeastern Asia, Central Africa, and Oceania 1. In the1960s, high stroke mortality in the Southeastern United States(the so-called Stroke Belt), especially along the coasts of Georgia and the Carolinas (so-called Stroke Buckle), was reported 6. As Mehndiratta et al. 4 reportedthat Asia is home toa very diverse population both in terms of ethnic variability and socioeconomic difference, with regions in various stages of development and epidemiological transition. The same is true in China. The prevalence of stroke, therefore, is also expected to exhibit geographical differences. At present, the available data on geographical differences of stroke prevalence in China are from two surveys (the 6-city stroke study and the 22 rural population study) conducted 30 years ago. The study reported a north-south gradient with a significantly higher incidence, prevalence, and mortality of stroke in the north compared to that in the south 7,8 .