Supplementary Material for: All-Cause and Cause-Specific Mortality in Parkinson’s Disease: A Meta-Analysis

Objectives: This study aimed to assess the overall and cause-specific standardized mortality ratios (SMRs) in patients diagnosed with Parkinson’s disease (PD). Methods: A systematic review was conducted, focusing on studies that evaluated SMRs for all causes and specific causes in PD patients compared to the general population. Searches were performed extensively in Medline, Embase, and Cochrane databases to compile relevant literature. A meta-analysis was subsequently conducted to evaluate all-cause, sex-specific, region-specific, and cause-specific SMRs in individuals with PD. Results: Twenty-one studies including 26,114 PD patients and 10,247 deaths from 12 European, 4 Asian, 3 Oceanian, 1 North American, and 1 Middle Eastern country met the inclusion criteria. The overall SMR analysis revealed that PD patients exhibited a 1.617-fold higher risk of all-cause mortality compared to the general population (SMR 1.617, 95% CI confidence interval [CI], 1.295–2.020, p < 0.001). Region-specific analysis showed significant SMR increases across all regions. Sex-specific analysis indicated elevated SMRs for both women (SMR 1.702, 95% CI 1.426–2.033, p < 0.001) and men (SMR 1.588, 95% CI 1.365–1.848, p < 0.001). PD onset before 60 years of age was associated with a higher, albeit not statistically significant, SMR compared to onset after 60 (SMR 1.991, 95% CI 1.313–3.021 vs. SMR 1.589, 95% CI 1.109–2.277). Cause-specific analyses revealed significantly increased SMRs for pneumonia (SMR 3.414, 95% CI 2.227–5.234, p < 0.001), cerebrovascular accidents (CVA) (SMR 1.484, 95% CI 1.048–2.102, p = 0.026), cardiovascular disease (SMR 1.449, 95% CI 1.156–1.816, p = 0.001), and suicide (SMR 2.049, 95% CI 1.383–3.035, p < 0.001), with no significant increase observed for cancer-related mortality. Conclusion: These findings highlight the increased mortality risk in PD patients, particularly due to causes such as pneumonia and CVA.