Population-based information about stroke incidence and prevalence is essential to inform health policy and practice. However, China's prevalence of stroke is unknown so far. To fill this important information gap, we did an epidemiological study of data from a large-scale national stroke screening survey.
Methods
From August, 2013, to May, 2014, the National Project Office of Stroke Prevention and Control organised a screening survey on 633 859 residents older than 40 years in 31 provinces. Following a random cluster sampling framework, structured questionnaires were used to collect information on risk factors, diagnosis history, treatment, and sociodemographic characteristics and were administered by community health workers trained by national and provincial specialists. A web-based reporting system was built for online data reporting. The institutional ethics committee approved the study protocol.
Findings
Among 633 859 surveyed subjects, 15 027 (2·37%) had stroke in 2013. The prevalence increases with age (0·54% of participants aged 40–50 years, 1·76% of those aged 50–60 years, 3·79% of those aged 60–70 years, and 8·87% of those older than 70 years). Prevalence seems to be higher in men than in women: the male:female ratio for all age groups combined is 1·23 (95% CI 1·21–1·26). The prevalence of stroke is slightly higher in rural residents than in urban residents (2·5% vs 2·2%).
Interpretation
Our study provided the first estimation of China's stroke prevalence on the basis of data from a large-scale survey. The estimated stroke prevalence and its association with age and sex are consistent with published findings from other developed countries. However, China's rural population has a higher probability of stroke than its urban counterpart, suggesting that the underlying socioeconomic disparities still persist. In view of the finding that the stroke prevalence of China, a developing country, is on par with that of developed countries, together with the rapid ageing, unhealthy lifestyle, and unmet medical need of the Chinese population, China's policy makers should pay more attention to effective prevention and control of stroke.
Funding
National Health and Family Planning Commission of China.
