Disparities in Deep Brain Stimulation Use for Parkinson's Disease in Ontario, Canada

Objective: To examine whether sociodemographic characteristics and health care utilization are associated with receiving deep brain stimulation (DBS) surgery for Parkinson's disease (PD) in Ontario, Canada. Methods: Using health administrative data, we identified a cohort of individuals aged 40 years or older diagnosed with incident PD between 1995 and 2009. A case-control study was used to examine whether select factors were associated with DBS for PD. Patients were classified as cases if they underwent DBS surgery at any point 1-year after cohort entry until December 31, 2016. Conditional logistic regression modeling was used to estimate the adjusted odds of DBS surgery for sociodemographic and health care utilization indicators. Results: A total of 46,237 individuals with PD were identified, with 543 (1.2%) receiving DBS surgery. Individuals residing in northern Ontario were more likely than southern patients to receive DBS surgery [adjusted odds ratio (AOR) = 2.23, 95% confidence interval (CI) = 1.15-4.34]; however, regional variations were not observed after accounting for medication use among older adults (AOR = 1.04, 95% CI = 0.26-4.21). Patients living in neighborhoods with the highest concentration of visible minorities were less likely to receive DBS surgery compared to patients living in predominantly white neighborhoods (AOR = 0.27, 95% CI = 0.16-0.46). Regular neurologist care and use of multiple PD medications were positively associated with DBS surgery. Conclusions: Variations in use of DBS may reflect differences in access to care, specialist referral pathways, health-seeking behavior, or need for DBS. Future studies are needed to understand drivers of potential disparities in DBS use.