Stroke in the People's Republic of China. II. Meta-analysis of hypertension and risk of stroke.

BACKGROUND AND PURPOSE In the People's Republic of China (PRC), stroke accounts for over 1 million deaths per year, more than three times the number of deaths from ischemic heart disease. To quantify the effect of hypertension on stroke in the PRC, we conducted a meta-analysis and estimated the population attributable risk of stroke due to hypertension. METHODS We searched the Chinese Medical Literature Index and MEDLINE databases to identify studies on the relationship between hypertension and stroke conducted in the PRC. The overall relative risk of stroke in hypertensive persons and the population attributable risk of stroke due to hypertension were calculated by pooling the risk estimates from individual studies. RESULTS A total of 12 epidemiological studies with 2379 stroke cases was identified. The overall relative risk of stroke associated with hypertension was 5.43 (95% confidence interval [CI], 4.62 to 6.39). The relative risk was similar for hemorrhagic (5.44; 95% CI, 3.99 to 7.40) and ischemic (5.25; 95% CI, 3.95 to 6.98) stroke. On the basis of data from the 1990 PRC population census, vital statistics, and the 1991 PRC National Hypertension Survey, the excess annual mortality from stroke due to hypertension was estimated to be at least 545,000 deaths, with a population attributable risk of 49.5%. CONCLUSIONS Our data suggest that hypertension is an important risk factor for stroke in the PRC and that hypertension may account for about half of all deaths from stroke in that country. Treatment and prevention of hypertension should be an important societal goal in the PRC.