| OR (95% CI) | |
| Ever used tobacco containing product‡ | 0.50 (0.42 to 0.60) |
| Ever consumed beer, wine or spirits regularly | 1.01 (0.83 to 1.23) |
| House with water supply from river or wellठ| 1.18 (0.97 to 1.43) |
| Ever been knocked unconscious‡ | 1.57 (1.29 to 1.91) |
| Knocked unconscious: | |
| Once vs never | 1.35 (1.09 to 1.68) |
| More than once¶ vs never | 2.53 (1.78 to 3.59) |
| Ever had a general anaesthetic for an operation | 0.81 (0.67 to 0.98) |
| Ever been treated by doctor after exposure to gas/smoke | 0.99 (0.49 to 1.20) |
| Ever taken sleeping pills for >1 year | 1.33 (1.07 to 1.65) |
| Ever taken medicines for anxiety for >1 year | 1.95 (1.54 to 2.47) |
| Ever taken medicines for depression for >1 year | 1.92 (1.49 to 2.49) |
| First-degree family history of Parkinson’s disease‡ | 4.85 (3.43 to 6.86) |
| Any exposure to solvents | 1.01 (0.84 to 1.23) |
| Any exposure to pesticides | 1.29 (1.02 to 1.63) |
| Any exposure to iron | 1.21 (0.87 to 1.44) |
| Any exposure to manganese | 1.05 (0.81 to 1.37) |
| Any exposure to copper | 1.00 (0.74 to 1.34) |
| Average annual intensity of exposure | |
| Solvents: | |
| Low exposure* vs no exposure | 1.17 (0.92 to 1.50) |
| High exposure* vs no exposure | 0.88 (0.69 to 1.12) |
| Pesticides: | |
| Low exposure* vs no exposure | 1.13 (0.82 to 1.57) |
| High exposure* vs no exposure | 1.41 (1.06 to 1.88) |
| Iron: | |
| Low exposure* vs no exposure | 1.11 (0.79 to 1.56) |
| High exposure* vs no exposure | 1.14 (0.82 to 1.59) |
| Manganese: | |
| Low exposure* vs no exposure | 1.22 (0.86 to 1.73) |
| High exposure* vs no exposure | 0.92 (0.64 to 1.32) |
| Copper: | |
| Low exposure* vs no exposure | 1.05 (0.70 to 1.59) |
| High exposure* vs no exposure | 0.94 (0.64 to 1.40) |
*Cut-off point for low/high exposure taken to be median value of those exposed.
†Logistic regression adjusting for age, sex, country, ever used tobacco-containing product, ever knocked unconscious and first-degree family history of Parkinson’s disease.
‡Odds ratios derived from a single logistic regression model with these factors as the only covariates.
§Excluding Malta water supply data.
¶Number of times knocked unconscious were once (n = 460), twice (n = 74), three times (n = 37), four times (n = 19), five times (n = 8), six times (n = 4), seven times (n = 1), 10 times (n = 4) and 20 times (n = 1).