A major new study forecasts that Parkinson’s disease will affect over 25 million people globally by 2050, urging immediate action to tackle the growing neurological health crisis.
Study: Projections for the prevalence of Parkinson’s disease and its driving factors in 195 countries and territories to 2050: a modeling study of Global Burden of Disease Study 2021. Image Credit: PeopleImages.com / Yuri A / Shutterstock.com
In a recent study published in the British Medical Journal, researchers conducted a cross-country analysis based on socio-demographic factors to predict the global prevalence of Parkinson’s disease (PD) by 2050.
Predicting the global burden of PD
PD is the second most common neurodegenerative disease. Thus, it is crucial to monitor regional, national, and global trends in the prevalence of PD to guide public health strategies.
Several studies have projected the future prevalence of PD in European countries and the United States; however, few have predicted PD prevalence in other countries and territories throughout the world. Previously, significant variations in PD prevalence were observed across age groups, sexes, regions, and years, thus demonstrating the complexity associated with forecasting future rates of PD.
Although age is often associated with an increased risk of PD, lifestyle factors, environmental exposures, and access to healthcare have also been implicated in PD development. The Socio-demographic Index, which captures important personal factors like educational attainment, encompassing per capita average incomes and fertility rates, is also significantly associated with PD prevalence.
About the study
The current study predicted the prevalence of PD in 2050 at regional, national, and global levels using sex, age, year, and the Socio-demographic Index. The researchers also identified different factors that temporally and spatially contributed to PD prevalence.
PD prevalence in 195 countries and territories between 2022 and 2050 was estimated by age, sex, and year. A probabilistic Bayesian model averaging approach and Poisson regression were used to estimate the age, sex, and location-stratified prevalence of PD.
The future prevalence was predicted by constructing three Poisson regression models and three new prevalence models by fitting a random walk model. These six models were subsequently incorporated into the Bayesian model averaging framework, following which the weighting assigned to each of the six models was assessed by studying their performance in projecting withheld data.
Study findings
The number of people living with PD globally in 2050 was estimated to be 25.2 million across all sexes and ages, which corresponds to a 112% increase compared to 2021. In 2050, the all-age prevalence of PD was forecasted to be 267 for every 100,000 individuals, 243 for women, and 295 for men, which reflected a 76% rise from 2021.
The age-standardized prevalence of PD was predicted to rise by 55% to 216. Rising PD cases, all age prevalence, and age-standardized prevalence are expected to increase at a slower pace.
The greatest increase in PD cases is predicted to occur in Sub-Saharan Africa, whereas central and eastern Europe were projected to experience the smallest increase. The highest increase in the age-related prevalence of PD is predicted in South Asia, North Africa, the Middle East, and Southeast Asia, whereas Australasia and North America are expected to see the smallest rise in cases.
The age-standardized PD prevalence was estimated to increase with the Socio-demographic Index between 2021 and 2050 and peak at 0.8. All age prevalence was forecasted to be highest among countries in the high-middle Socio-demographic Index fifth part of the distribution.
The increase in all-age PD prevalence is expected to be highest in the middle fifth of the Socio-demographic Index and lowest in the highest fifth. Spain, China, and Andorra were forecasted to have the highest PD prevalence, whereas Somalia, Niger, and Chad were forecasted to have the lowest PD prevalence.
An age-dependent increase in PD prevalence was observed for both sexes, peaking between 85 and 89. In 2050, the prevalence of PD is projected to be higher in men than women across all age groups.
Between 2021 and 2050, changes in PD prevalence, population growth, and population aging are predicted to contribute 3%, 20%, and 89%, respectively, to the increase in the number of PD cases globally. If all individuals adhere to regular physical activity, the 2050 prediction for PD cases would reduce by 4.9%.
Conclusions
PD will likely become a greater public health threat by 2050. Rising PD cases are expected to affect men more than women, particularly those residing in countries with values of the Socio-demographic Index in the middle.
The study findings emphasize the need for continued research dedicated to developing novel drugs, gene engineering techniques, and cell replacement therapies that can improve PD patient prognoses and their quality of life. To ensure the accuracy of these predictions, additional studies are also needed to identify other risk/protective factors associated with PD.
Journal reference:
- Su, D., Cui, Y., He, C., et al. (2025) Projections for prevalence of Parkinson’s disease and its driving factors in 195 countries and territories to 2050: modelling study of Global Burden of Disease Study 2021. BMJ. doi:10.1136/bmj-2024-080952