Scientists are calling for immediate action to tackle the growing neurological health crisis of Parkinson’s disease, with cases likely to affect 25m within the next quarter of a century – and the biggest increase expected in sub-Saharan Africa.
The findings of the study, in which researchers conducted a cross-country analysis based on socio-demographic factors to predict the global prevalence of Parkinson’s by 2050, were published in The BMJ.
Predicting global burden
With it being the second most common neurodegenerative disease in the world, it is crucial to monitor regional, national and global trends in the prevalence of Parkinson’s to guide public health strategies.
Several studies have projected the future prevalence in European countries and the United States, however, few have predicted prevalence in other countries and territories.
Previously, reports News-Medical.net, significant variations in prevalence were observed across age groups, sexes, regions and years, demonstrating the complexity associated with forecasting future rates of Parkinson’s.
But although age is often associated with an increased risk, lifestyle factors, environmental exposures, and access to healthcare have also been implicated.
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 prevalence.
About the study
The current study, led by a large team of Chinese scientists, predicted the prevalence of Parkinson’s 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 growth.
Prevalence in 195 countries and territories between 2022 and 2050 was estimated by age, sex, and year, and a probabilistic Bayesian model averaging approach and Poisson regression were used to estimate the age, sex and location-stratified prevalence.
The future prevalence was predicted by constructing three Poisson regression models and three new prevalence models by fitting a random walk model. These were subsequently incorporated into the Bayesian model averaging framework, after which the weighting assigned to each of the six models was assessed by studying their performance in projecting withheld data.
What they found
The number of people with the disease globally in 2050 was estimated to be 25.2m across all sexes and ages, corresponding to a 112% increase compared with 2021. In 2050, the all-age prevalence was forecasted to be 267 for every 100 000 individuals, 243 for women, and 295 for men, reflecting a 76% rise from 2021.
The age-standardised prevalence was predicted to rise by 55% to 216. Rising cases, all age prevalence, and age-standardised prevalence are expected to increase at a slower pace.
The greatest increase in Parkinson’s cases is predicted for sub-Saharan Africa, whereas central and eastern Europe were projected to experience the smallest increase. The highest increase in the age-related prevalence 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-standardised 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 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 prevalence, whereas Somalia, Niger and Chad were forecasted to have the lowest Parkinson’s prevalence.
An age-dependent increase in prevalence was observed for both sexes, peaking between 85 and 89. In 2050, the prevalence is projected to be higher in men than women across all age groups.
Between 2021 and 2050, changes in prevalence, population growth, and population aging are predicted to contribute 3%, 20%, and 89%, respectively, to the increase in the number of cases globally. If all individuals adhere to regular physical activity, the 2050 prediction for cases would reduce by 4.9%.
Conclusions
Parkinson’s will probably become a greater public health threat by 2050. Rising cases are expected to affect men more than women, particularly those living in countries with values of the Socio-demographic Index in the middle.
The study findings emphasise the need for continued research dedicated to developing novel drugs, gene engineering techniques, and cell replacement therapies that can improve 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 Parkinson’s.
Study details
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
Dongning Su, Yusha Cui, Chengzhang He, et al.
Published in The BMJ on 5 March 2025
Abstract
Objective
To predict the global, regional, and national prevalence of Parkinson’s disease by age, sex, year, and Socio-demographic Index to 2050 and quantify the factors driving changes in Parkinson’s disease cases.
Design
Modelling study.
Data source
Global Burden of Disease Study 2021.
Main outcome measures
Prevalent number, all age prevalence and age standardised prevalence of Parkinson’s disease in 2050, and average annual percentage change of prevalence from 2021 to 2050; contribution of population ageing, population growth, and changes in prevalence to the growth in Parkinson’s disease cases; population attributable fractions for modifiable factors.
Results
25.2 (95% uncertainty interval 21.7 to 30.1) million people were projected to be living with Parkinson’s disease worldwide in 2050, representing a 112% (95% uncertainty interval 71% to 152%) increase from 2021. Population ageing (89%) was predicted to be the primary contributor to the growth in cases from 2021 to 2050, followed by population growth (20%) and changes in prevalence (3%). The prevalence of Parkinson’s disease was forecasted to be 267 (230 to 320) cases per 100 000 in 2050, indicating a significant increase of 76% (56% to 125%) from 2021, whereas the age standardised prevalence was predicted to be 216 (168 to 281) per 100 000, with an increase of 55% (50% to 60%) from 2021. Countries in the middle fifth of Socio-demographic Index were projected to have the highest percentage increase in the all age prevalence (144%, 87% to 183%) and age standardised prevalence (91%, 82% to 101%) of Parkinson’s disease between 2021 and 2050. Among Global Burden of Disease regions, East Asia (10.9 (9.0 to 13.3) million) was projected to have the highest number of Parkinson’s disease cases in 2050, with western Sub-Saharan Africa (292%, 266% to 362%) experiencing the most significant increase from 2021. The ≥80 years age group was projected to have the greatest increase in the number of Parkinson’s disease cases (196%, 143% to 235%) from 2021 to 2050. The male-to-female ratios of age standardised prevalence of Parkinson’s disease were projected to increase from 1.46 in 2021 to 1.64 in 2050 globally.
Conclusions
By 2050 Parkinson’s disease will have become a greater public health challenge for patients, their families, care givers, communities, and society. The upward trend is expected to be more pronounced among countries with middle Socio-demographic Index, in the Global Burden of Disease East Asia region, and among men. This projection could serve as an aid in promoting health research, informing policy decisions, and allocating resources.
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