Mortality of Deep Brain Stimulation and Risk Factors in Patients With Parkinson's Disease: A National Cohort Study in Korea

BACKGROUND: This study aimed to investigate 1) long-term outcomes of deep brain stimulation (DBS), such as mortality after DBS as well as the causes of death, 2) demographic and socioeconomic factors influencing mortality, and 3) comorbidities affecting mortality after DBS in patients with Parkinson’s disease (PD). METHODS: This study analyzed the National Health Insurance Service-National Health Information Database. Data on patients with PD diagnosis codes from 2002 to 2019 were extracted and analyzed. Data on the causes of death were obtained by linking the causes of death to data from Statistics Korea. The Kaplan-Meier method with the log-rank test was used for survival analysis. Multivariate Cox regression analyses were used to estimate hazard ratios (HRs) and their 95% confidence intervals. Regarding comorbidities such as PD dementia and fracture, which did not satisfy the assumption for the proportional HR, time-dependent Cox analysis with the Mantel-Byar method was used. RESULTS: From 2005 to 2017, among 156,875 patients diagnosed with PD in Korea, 1,079 patients underwent DBS surgery, and 251 (23.3%) had died by 2019. The most common cause of death (47.1%) was PD. In the multivariate Cox regression analysis, the higher the age at diagnosis and surgery, the higher the mortality rate. The men and medical aid groups had significantly higher mortality rates. PD dementia and fracture were identified as risk factors for mortality. CONCLUSION: Older age at diagnosis and surgery, being male, the use of medical aid, and the comorbidity of dementia and fractures were associated with a higher risk of mortality after DBS in patients with PD. Neurologists should consider these risk factors in assessing the prognosis of PD patients undergoing DBS.