Disability trends in Spain by sex: An Age-Period-Cohort analysis.

Objectives: Disability is a complex concept, and generally refers to a situation where the carrying out of daily routines and social interactions is made more difficult for people. Despite research suggesting an increase in disability worldwide, there are few studies that afford a longitudinal perspective, with most focused exclusively on older populations. This study takes a generational perspective with the aim of analyzing the trend of disability in Spain STUDY DESIGN: Age-period-cohort analysis.

Method: To address a gap in the existing research, this study carries out an Age-Period-Cohort analysis to examine disability time-trends in Spain by sex, using data from various cross-sectional surveys conducted in 1999 (n = 218,185), 2008 (n = 258,187), and 2020 (n = 164,254).

Results: The results of this study contribute to knowledge of disability time-trends, and provide overall-population scope and sex differentials. While age was found to be the primary factor in an increase in disability, this study afforded insight into a decline in disability over period, observed after removing the age effect. Further, after controlling for age and period, significant differences in the prevalence of disability by cohort were observed. Differences by sex were found, with differing patterns of disability observed for female and male cohorts. This study also found an increase in the prevalence of disability in the youngest cohort, despite a general decrease in disability for generations born after 1960.

Conclusions: Between generational cohorts, there are differing patterns for the prevalence of disability which cannot be explained by age, or by the period through which the cohort has lived.