This first individual patient data meta-analysis of population-based incidence cohorts provides robust prognostic data, with fewer selection biases than previous PD studies, for informing people with PD about prognosis. In incidence cohorts, overall PD prognosis is worse than previously suggested, with key outcomes often occurring early. Further work should develop validated prognostic models for objective stratification of prognostic risk and for personalized medicine. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Macleod et al. (Sat,) studied this question.