Global, regional and national temporal trends in Parkinson’s disease incidence, disability-adjusted life year rates in middle-aged and older adults: a cross-national inequality analysis and Bayesian age-period-cohort analysis based on the global burden of disease 2021

Parkinson’s disease (PD) ranks as the second most prevalent neurodegenerative disorder; however, its epidemiological characteristics among middle-aged and older adults at global, regional, and national levels remain inadequately documented.

This study assessed temporal trends in PD among middle-aged and older adults by extracting incidence rates, disability-adjusted life year (DALY) rates, and corresponding age-specific rates (ASRs) from the Global Burden of Disease (GBD) database spanning 1990 to 2021. Estimated annual percentage change (EAPC) was employed to analyze trends over the past 30 years. The slope index of inequality (SII) and concentration index (CI) were utilized to evaluate disparities in the burden of PD across various countries. Additionally, Bayesian age-period-cohort (BAPC) modeling was applied to project DALY figures for the next 15 years.

In 2021, the global incidence and DALY rates for middle-aged and older adults with PD stood at 79.68 and 477.50 cases per 100,000 population, respectively. Both incidence and DALY rates have exhibited an upward trajectory over the past 32 years, with EAPCs of 1.2 (95% UI: 1.1–1.3) and 0.6 (95% UI: 0.5–0.7), respectively. Among the five sociodemographic index (SDI) regions, the high-middle SDI region reported the highest incidence and DALY rates for PD in 2021, at 93.93 and 512.29 cases per 100,000 population, respectively. A positive correlation was observed between the SDI and age-specific incidence rate (ASIR) as well as age-specific DALY rate (ASDR). Disparities in the burden of PD among middle-aged and older adults, associated with SDI, are on the rise and are primarily concentrated in high SDI countries. It is projected that the global incidence and DALY rates for middle-aged and older adults with PD will experience significant increases over the next 15 years.

The global burden of PD among middle-aged and older adults has markedly escalated over the past 32 years, particularly in high-middle SDI regions. These findings underscore the necessity for the development of effective interventions and public health policies, contributing to the attainment of the sustainable development goals established by the World Health Organization (WHO).