Understanding stroke mortality trends in Spain: A comprehensive age-period-cohort and joinpoint analysis

This study aims to update and evaluate the age-period-cohort (A-P-C) effects on stroke mortality in Spain over the period 1982-2021.

Data on stroke mortality and population by age and sex were obtained from the database of the National Institute of Statistics for the years 1982-2021. Joinpoint trend analysis software from the US National Cancer Institute was used to estimate the rates and their time trends. The effects of age, period, and cohort were estimated using a log-linear Poisson model with a likelihood penalty function to address the problem of identifiability.

For both sexes (-4.3% for men and -4.6% for women), age-standardized mortality rates (all ages) decreased over the study period. With the exception of the 30-64 age group, where rates for women have been stable since 2012, the rate of decline has slowed in recent years for both sexes. Since the beginning of the 20th century, the estimated relative risk in birth cohorts for both sexes followed a steady downward trend for all birth cohorts. However, the decline in risk has slowed down for women born between 1947 and 1962. Both men and women have experienced a decline in RR, which has stabilized (women) or slowed down (men) in the last decade.

Both period and cohort effects are present in the decline in Spanish stroke mortality between 1982 and 2021. It is unlikely that the decrease in mortality has offset the possible increase in incidence in younger cohorts. This has led to a slowing (in men) or stagnation (in women) of the current decline in stroke mortality. Therefore, we must continue to focus on prevention.