| OR (95% CI) | |
| Ever used tobacco containing product‡ | 0.48 (0.40 to 0.58) |
| Ever consumed beer, wine or spirits regularly | 0.92 (0.74 to 1.15) |
| House with water supply from river or wellठ| 1.23 (1.00 to 1.52) |
| Ever been knocked unconscious‡ | 1.52 (1.23 to 1.88) |
| Knocked unconscious: | |
| Once vs never | 1.28 (1.01 to 1.62) |
| More than once vs never | 2.56 (1.78 to 3.69) |
| Ever had a general anaesthetic for an operation | 0.74 (0.61 to 0.91) |
| Ever been treated by doctor after exposure to gas/smoke | 1.24 (0.60 to 2.57) |
| Ever taken sleeping pills for >1 year | 1.38 (1.10 to 1.75) |
| Ever taken medicines for anxiety for >1 year | 2.00 (1.55 to 2.57) |
| Ever taken medicines for depression for >1 year | 1.90 (1.44 to 2.51) |
| First-degree family history of Parkinson’s disease‡ | 4.63 (3.21 to 6.69) |
| Any exposure to solvents | 1.06 (0.86 to 1.30) |
| Any exposure to pesticides | 1.25 (0.97 to 1.61) |
| Any exposure to iron | 1.07 (0.82 to 1.40) |
| Any exposure to manganese | 0.98 (0.73 to 1.31) |
| Any exposure to copper | 1.01 (0.73 to 1.39) |
| Average annual intensity of exposure to: | |
| Solvents: | |
| Low exposure* vs no exposure | 1.21 (0.93 to 1.57) |
| High exposure* vs no exposure | 0.94 (0.72 to 1.21) |
| Pesticides: | |
| Low exposure* vs no exposure | 1.09 (0.77 to 1.55) |
| High exposure* vs no exposure | 1.39 (1.02 to 1.89) |
| Iron: | |
| Low exposure* vs no exposure | 1.05 (0.73 to 1.51) |
| High exposure* vs no exposure | 1.10 (0.77 to 1.59) |
| Manganese: | |
| Low exposure* vs no exposure | 1.10 (0.75 to 1.62) |
| High exposure* vs no exposure | 0.88 (0.59 to 1.30) |
| Copper: | |
| Low exposure* vs no exposure | 1.09 (0.71 to 1.69) |
| High exposure* vs no exposure | 0.94 (0.61 to 1.43) |
*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.