General characteristics of the participants
| Characteristics | Total participants | ||
| Parkinson’s disease (n, %) | Control (n, %) | P-value | |
| Age (years old) | 1.000 | ||
| 60–64 | 388 (11.1) | 1552 (11.1) | |
| 65–69 | 660 (18.8) | 2640 (18.8) | |
| 70–74 | 903 (25.7) | 3612 (25.7) | |
| 75–79 | 835 (23.8) | 3340 (23.8) | |
| 80–84 | 498 (14.2) | 1992 (14.2) | |
| 85+ | 226 (6.4) | 904 (6.4) | |
| Sex | 1.000 | ||
| Male | 1336 (38.1) | 5344 (38.1) | |
| Female | 2174 (61.9) | 8696 (61.9) | |
| Income | 1.000 | ||
| 1 (lowest) | 325 (9.3) | 1300 (9.3) | |
| 2 | 283 (8.1) | 1132 (8.1) | |
| 3 | 145 (4.1) | 580 (4.1) | |
| 4 | 154 (4.4) | 616 (4.4) | |
| 5 | 179 (5.1) | 716 (5.1) | |
| 6 | 190 (5.4) | 760 (5.4) | |
| 7 | 251 (7.2) | 1004 (7.2) | |
| 8 | 256 (7.3) | 1024 (7.3) | |
| 9 | 383 (10.9) | 1532 (10.9) | |
| 10 | 584 (16.6) | 2336 (16.6) | |
| 11 (highest) | 760 (21.7) | 3040 (21.7) | |
| Region of residence | 1.000 | ||
| Urban | 1467 (41.8) | 5868 (41.8) | |
| Rural | 2043 (58.2) | 8172 (58.2) | |
| *CCI score | <0.001† | ||
| 0 | 325 (9.3) | 3049 (21.7) | |
| 1 | 132 (3.8) | 659 (4.7) | |
| 2 | 240 (6.8) | 1173 (8.4) | |
| ≥3 | 2813 (80.1) | 9159 (65.2) | |
| Death | 1214 (34.6) | 2661 (19.0) | <0.001† |
*CCI, Charlson Comorbidity Index (calculated without including pulmonary disease).
†χ2 test or Fisher’s exact test. Significance at p<0.05.