Variation in the frequency of intracerebral haemorrhage and ischaemic stroke in China: A national, multicentre, hospital register study

Background: Intracerebral haemorrhage (ICH) accounts for about one third of all strokes in China, a proportion that is three times higher than in Western populations. We aimed to determine the frequency distribution of ICH in China. Methods: Using the ChinaQUEST hospital register database, the proportional frequency of ICH was determined by region and city location. Linear regression analysis was then performed to evaluate associations between the frequency of ICH and distribution of risk factors by city. Results: Proportional frequency of ICH was 25% overall, but varied markedly across major geographical regions ranging from 11 to 36%. The differences between cities were even more profound, with the age- and sex-standardised proportional frequencies ranging from 5% in Guangzhou to 55% in Baoji. Significant associations were found between the proportional frequency of ICH and history of diabetes, hyperlipidaemia, and a high body mass index. Notably, cities with higher frequencies of diabetic, hyperlipidaemic or overweight individuals tended to have lower frequencies of ICH. Conclusions: Considerable interregional variation in the distribution of ICH in China can be partially explained by differences in distribution of risk factors in the population.