Risk of Parkinsons Disease in Stroke Survivors: A Nationwide Cohort Study in South Korea

Background: Previous studies have examined the risk of stroke in patients with Parkinsons disease (PD), but the incidence of PD onset among stroke survivors and its risk according to severity of post-stroke disabilities is scarcely investigated. This study aims to determine whether the risk of PD is increased among stroke survivors using a retrospective cohort with a large population-based database.Method: We used data collected by the Korean National Health Insurance Service from 20102018 and examined 307,361 stroke survivors and 380,917 sex- and age-matched control subjects to uncover the incidence of PD. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI), and the risk of PD was compared according to presence and severity of disability. Results: During 4.31 years of follow-up, stroke survivors had a 1.67 times higher risk of PD compared to matched control subjects (adjusted HR, 1.67; 95% CI, 1.571.78). The risk of PD was greater among stroke survivors with disabilities than among those without disabilities, even after adjustment for multiple covariates (adjusted HR, 1.72; 95% CI, 1.551.91 and adjusted HR, 1.66; 95% CI, 1.561.77, respectively). Conclusion: Our study demonstrated increased risk of PD onset among stroke survivors. Health professionals need to pay careful attention to detecting movement disorders as clues for diagnosing PD. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research received no external funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This research was approved by the Institutional Review Board (IRB) of Samsung Medical Center (IRB no. 2020-12-068) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study are available from the corresponding author, [DWS], upon reasonable request.