Objectives: Varying survival rates have been reported across studies on patients with Parkinson’s disease (PD). In particular, early survival rates in cases of PD relative to the general population remain unclear. In this study, we reported the 10-year relative survival rate of PD patients using a nationwide database.
Methods: We identified incident PD cases from 2004-2006 using the PD registration codes from the National Health Insurance Service (NHIS) database covering the entire South Korean population. Expected survival of the general South Korean population according to age and gender was ascertained from the 2004-2017 Korean Census Life Table provided by the Statistics Korea. Relative survival up to 10 years was evaluated by adjusting all-cause survival for expected survival, estimated from population life tables and matched by sex, age, and year of diagnosis. We also assessed mortality risk of PD compared to matched non-PD controls using the COX proportional hazards model after adjusting for sex, age, region of residence, income, comorbidities, comedications, and the modified Charlson comorbidity index score.
Results: Of the 10,159 PD patients, 4,675 (46.0%) patients survived 10 years after diagnosis. Relative survival rates decreased with time after diagnosis (0.972 after 1 year, 0.773 after 5 years, and 0.590 after 10 years; Figure 1). Ten-year relative survival gradually decreased with age at diagnosis. Men had a lower relative survival rate than women 2 years post diagnosis, and if they were over 60 years (Figure 2). Compared to 39,574 corresponding non-PD controls, patients with PD showed a higher mortality risk even after adjusting for potential confounders (adjusted hazard ratio=1.87; 95% CI, 1.81–1.94). Factors found to be associated with a higher risk of mortality included male sex, older age, region of residence, low income, hypertension, diabetes, ischemic heart disease, congestive heart failure, cancer, tuberculosis, atrial fibrillation, chronic kidney disease, cerebrovascular disease, and dementia. In contrast, dyslipidemia and peripheral arterial disease were associated with a lower risk of mortality.
Conclusions: Based on a nationwide population-based database, PD patients were found to have a lower 10-year relative survival rate. PD patients might have a lower survival rate than the normal population even during the early stages of the disease. Improvements in clinical practice, effective treatment of pertinent causes of death, and further investigation regarding survival and mortality factors may be useful in preventing premature mortality among PD patients. |
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Figure 1. Relative survival rates of patients with Parkinson’s disease. (A) Relative survival rates from diagnosis, (B) 10-year relative survival rates according to the age at diagnosis.
Figure 2. Differences in relative survival rates between men and women with Parkinson’s disease. (A) Relative survival rates from diagnosis, (B) 10-year relative survival rates according to the age at diagnosis.
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