Table 2.
Appendectomy and risk of Parkinson's disease (PD), nationwide case-control analysis.
| N | PD cases | Controls | Model 1aa | Model 2b |
|---|---|---|---|---|
| N | OR (95% CI) | OR (95% CI)b | ||
| Appendectomy | ||||
| No | 76,742 (97.6) | 3,067,880 (97.5) | 1 | 1 |
| Yes | 1,908 (2.4) | 78,120 (2.5) | 0.98 (0.93–1.02) | 0.84 (0.80–0.88) |
| Years before index date | ||||
| <5 | 232 (0.3) | 11,104 (0.4) | 0.84 (0.73–0.95) | 0.69 (0.60–0.79) |
| ≥5 | 1,676 (2.1) | 67,016 (2.1) | 1.00 (0.95–1.05) | 0.87 (0.83–0.92) |
| <10 | 511 (0.6) | 22,371 (0.7) | 0.91 (0.84–1.00) | 0.76 (0.69–0.83) |
| ≥10 | 1,397 (1.8) | 55,749 (1.8) | 1.00 (0.95–1.06) | 0.88 (0.83–0.93) |
| <20 | 1,025 (1.3) | 44,027 (1.4) | 0.93 (0.87–0.99) | 0.78 (0.73–0.83) |
| ≥20 | 883 (1.1) | 34,093 (1.1) | 1.04 (0.97–1.11) | 0.93 (0.87–0.99) |
| Stratified by Sex | ||||
| Male | 874 (1.1) | 36,133 (1.1) | 0.97 (0.90–1.03) | 0.84 (0.78–0.90) |
| Female | 1,034 (1.3) | 41,987 (1.3) | 0.98 (0.92–1.05) | 0.85 (0.80–0.90) |
| Stratified by age at index date, years | ||||
| <60 | 253 (0.3) | 9,538 (0.3) | 1.06 (0.94–1.21) | 0.90 (0.79–1.02) |
| 60–69 | 444 (0.6) | 17,756 (0.6) | 1.00 (0.91–1.10) | 0.85 (0.77–0.93) |
| 70–79 | 776 (1.0) | 32,535 (1.0) | 0.95 (0.89–1.02) | 0.82 (0.76–0.88) |
| ≥80 | 435 (0.6) | 18,291 (0.6) | 0.95 (0.86–1.05) | 0.86 (0.78–0.94) |
a
Logistic regression conditional on birth year and sex;
b
Logistic regression conditional on birth year and sex, and additionally adjusted for country of birth, highest achieved education, COPD, comorbidity index, and number of hospital visits.