Table 3 Adjusted results† (all cases vs controls)
OR (95% CI)
Ever used tobacco containing product‡0.50 (0.42 to 0.60)
Ever consumed beer, wine or spirits regularly1.01 (0.83 to 1.23)
House with water supply from river or well‡§1.18 (0.97 to 1.43)
Ever been knocked unconscious‡1.57 (1.29 to 1.91)
Knocked unconscious:
    Once vs never1.35 (1.09 to 1.68)
    More than once¶ vs never2.53 (1.78 to 3.59)
Ever had a general anaesthetic for an operation0.81 (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 year1.33 (1.07 to 1.65)
Ever taken medicines for anxiety for >1 year1.95 (1.54 to 2.47)
Ever taken medicines for depression for >1 year1.92 (1.49 to 2.49)
First-degree family history of Parkinson’s disease‡4.85 (3.43 to 6.86)
Any exposure to solvents1.01 (0.84 to 1.23)
Any exposure to pesticides1.29 (1.02 to 1.63)
Any exposure to iron1.21 (0.87 to 1.44)
Any exposure to manganese1.05 (0.81 to 1.37)
Any exposure to copper1.00 (0.74 to 1.34)
Average annual intensity of exposure
    Solvents:
        Low exposure* vs no exposure1.17 (0.92 to 1.50)
        High exposure* vs no exposure0.88 (0.69 to 1.12)
    Pesticides:
        Low exposure* vs no exposure1.13 (0.82 to 1.57)
        High exposure* vs no exposure1.41 (1.06 to 1.88)
    Iron:
        Low exposure* vs no exposure1.11 (0.79 to 1.56)
        High exposure* vs no exposure1.14 (0.82 to 1.59)
    Manganese:
        Low exposure* vs no exposure1.22 (0.86 to 1.73)
        High exposure* vs no exposure0.92 (0.64 to 1.32)
    Copper:
        Low exposure* vs no exposure1.05 (0.70 to 1.59)
        High exposure* vs no exposure0.94 (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).