Global trends in Alzheimer’s disease and other dementias in adults aged 55 and above (1992–2021): An age-period-cohort analysis based on the GBD 2021
Fig 5
Local drift of ADOD incidence (1992–2021) across SDI quintiles, along with age, period, and birth cohort effects, was analyzed using APC models.
A: Local drift of ADOD incidence across nine age groups (1992–2021). The local drift (i.e., annual percentage change of age-specific incidence, % per year) and its associated 95% CIs are indicated by the dots and shaded areas; B: The age effect is illustrated by longitudinal age-specific rates, adjusted for variations across birth cohorts while accounting for period-specific deviations; C: Period effects are quantified as the relative risk of ADOD incidence across time periods, calculated by comparing age-specific rates in each observation period (e.g., 2017–2021) to those in the baseline period (1992–1996); D: Cohort effects are shown as the cohort relative risk of incidence, calculated as the ratio of age-specific rates from the 1892–1901 cohort to the 1957–1966 cohort, with the reference cohort set at 1932–1941. The dots and shaded areas represent the incidence rates or rate ratios and their corresponding 95% CIs. ADOD, Alzheimer’s disease and other dementias; SDI, socio-demographic index.