Age-period-cohort analysis of stroke incidence in China and India from 1990 to 2019 and predictions up to 2042

Abstract Objective To analyze the trend of stroke incidence in Chinese and Indian residents from 1990 to 2019, to discuss the effects of age, period, and birth cohort factors on the incidence of stroke in China and India, respectively, and to predict the future incidence trends to provide scientific reference for stroke prevention and control measures in China and India. Methods We downloaded the stroke incidence data of China and India residents from the GBD2019 database from 1990 to 2019 and fitted the trend of stroke incidence data of China city residents by using the Joinpoint regression model to calculate the annual percentage change (APC) and the average annual percentage change (AAPC). In addition, the effects of age, period, and birth cohort on the incidence of stroke were investigated by building an age-period-cohort model. Bayesian age-period-cohort models were used to predict stroke incidence by 2042. Results The overall trend in stroke incidence from 1990 to 2019 was downward in both China and India. Age-standardized incidence rates in China and India decreased from 221.51/100,000 and 121.35/100,000 in 1990 to 200.84/100,000 and 110.7/100,000 in 2019, respectively. Joinpoint regression models showed that stroke incidence in China declined by an average of 0.35% per year (AAPC = − 0.35%, P < 0.001), with the fastest decline occurring from 2005 to 2010 (AAPC = − 2.18%, P < 0.001), and that stroke incidence in India declined by an average of 0.32% per year (AAPC = − 0.32%, P < 0.001), with the fastest decline occurring from 1995 to 2000 (APC = − 1.57%, P < 0.001). Age-period-cohort models showed that the relative risk (RR) of stroke increased with age and period in both countries but decreased with birth cohort. Projections indicate a decreasing trend in the incidence of stroke in the Chinese population by 2042. The ASIR for men and women decreases to 186.87/100,000 and 161.97/100,000, respectively, while the incidence of stroke in the Indian population shows an upward trend, increasing to 133.85/100,000 and 209.16/100,000 for men and women, respectively. Conclusion The age-standardized incidence of stroke in both China and India showed a decreasing trend from 1990 to 2019. In both countries, the risk of stroke increased with increasing age and period and decreased with birth cohort. Increasing age is a key factor influencing stroke incidence in both countries, and stroke remains a major public health problem in both countries, especially because they are the two most populous countries in the world.