A population-based case-control study of 1250 stroke deaths in rural Bangladesh

Background and purpose: There are limited population-based studies to determine the risk factors for stroke in Bangladesh. Methods: A health and demographic surveillance system has been maintained in Matlab, Bangladesh (population 223 886, 142 villages in 2008). All adult stroke and injury deaths (20052008) were monitored by verbal autopsy. Risk factors for stroke deaths were calculated using a multivariable logistic regression model with adult injury deaths as controls. Results: A total of 1250 stroke deaths (51% women; mean age 72.3 years, range 20101) occurred out of 4955 total deaths and were compared with 246 adult injury deaths (47% women, mean age 55.8 years, range 20100). The population-attributable mortality of stroke was 25.2% based on the verbal autopsy instrument and 17.8% when accounting for the reported sensitivity and specificity of a similar verbal autopsy instrument that has been validated for stroke death. Risk of stroke death was significantly increased with hypertension (OR 7.94, 95% CI 4.4415.54, P < 0.001), diabetes mellitus (OR 2.54, 1.216.21, P = 0.02), and betel consumption (OR 2.36, 1.453.80, P < 0.001) when adjusted for age and sex. An increased risk was not observed with heart disease (OR 1.37, 0.455.95, P = 0.62), cigarette smoking (OR 1.41, 0.822.45, P = 0.22), tobacco powder (OR 1.15, 0.307.64, P = 0.86), or cigar/hookah pipe smoking 0.94 (0.452.18, P = 0.88) when adjusted for age and sex. There were more strokes in winter (DecemberMarch) than summer (JuneSeptember) (P < 0.001). Conclusions: There is a high modifiable burden of risk factors for adult stroke deaths in rural Bangladesh, most notably including hypertension. Betel consumption may be an under-recognized risk factor for stroke death.