Age-period-cohort analysis of stroke and subtype burdens from 1990 to 2021

Stroke is associated with high morbidity and mortality. The study aimed to assess 32-year trends in stroke incidence and mortality globally and across different sociodemographic index (SDI) regions, and their links to age, period, and birth cohort.

On the basis of the Global Burden of Disease (GBD) 2021 database, an age-period-cohort (APC) model was used to estimate the overall annual percentage change in ischemic stroke (IS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) incidence and mortality from 1990 to 2021 (net drift), the annual percentage change from 0-4 years to 95-100 years (local drift), and the period and cohort relative risk (period/cohort effect). The incidence and mortality of three stroke subtypes decreased globally from 1990 to 2021, while the total number of cases increased significantly. The net drifts of IS incidence and mortality were -0.52 and -1.47 per year, respectively. The net drifts of ICH morbidity and mortality were -1.41 and -1.64 per year, respectively. The net drifts of SAH morbidity and mortality were -1.31 and -2.77 per year, respectively. Age effects on the three stroke subtypes tended to increase, whereas period effects and cohort effects tended to decrease. IS burden was more prominent in middle and high-SDI countries, whereas ICH and SAH burdens were more concentrated in low-SDI regions.

Corresponding strategies should be formulated according to the characteristics of different regions. Strengthening stroke management in the elderly population is recommended, but attention should also be paid to SAH in the middle-aged population.