Table 3.
Odds ratio (OR) with 95% confidence interval (CI) of ALS risk according to personal characteristics and clinical factors.
| Factors | Cases (y/n) | Controls (y/n) | OR a | OR b | (95% CI) |
|---|---|---|---|---|---|
| Personal information and habits | |||||
| Dominant hand | |||||
| Right-handed | 83 | 124 | Ref. | ||
| Left-handed | 4 | 4 | 1.49 | 1.45 | (0.34–6.14) |
| Ambidextrous | 8 | 7 | 1.71 | 1.73 | (0.59–5.02) |
| Non-right handed | 12/83 | 11/124 | 1.63 | 1.63 | (0.67–3.92) |
| Dominant foot | |||||
| Right | 85 | 123 | Ref. | ||
| Left | 11 | 10 | 1.63 | 1.62 | (0.64–4.06) |
| Ambidextrous | 2 | 1 | 0.74 | 0.78 | (0.07–8.84) |
| Non-right | 12/83 | 12/123 | 1.48 | 1.47 | (0.62–3.50) |
| Regular use of skin cream c | 25/43 | 66/68 | 0.60 | 0.53 | (0.27–1.06) |
| Having or ever having had amalgam fillings c | 42/26 | 79/55 | 1.12 | 1.17 | (0.62–2.20) |
| Regular use of chewing gum c | 16/52 | 18/116 | 1.99 | 2.09 | (0.92–4.74) |
| Eat fish c | 48/20 | 120/14 | 0.28 | 0.27 | (0.12–0.60) |
| Eat ≥3 fish-based meals per week c | 6/62 | 18/116 | 0.62 | 0.58 | (0.22–1.58) |
| Wine drinking c | 43/52 | 85/50 | 0.49 | 0.46 | (0.26–0.82) |
| Alcohol units intake c,d | 10/58 | 21/113 | 0.93 | 0.98 | (0.42–2.28) |
| Main source of drinking water | |||||
| No preference | 34 | 46 | Ref. | Ref. | |
| Municipal water | 24 | 55 | 0.59 | 0.55 | (0.28–1.07) |
| Private wells | 4 | 3 | 1.80 | 1.44 | (0.29–7.03) |
| Bottled water | 33 | 31 | 1.44 | 1.24 | (0.62–2.44) |
| Current use of any private well water | 12/83 | 9/126 | 2.02 | 1.91 | (0.76–4.79) |
| Ever use a private well/fountain for drinking water | 38/57 | 46/89 | 1.29 | 1.38 | (0.73–2.27) |
| Current use of a private well/fountain for irrigation | 14/81 | 30/105 | 0.60 | 0.57 | (0.28–1.16) |
| Ever smoking | 49/46 | 65/70 | 1.15 | 1.19 | (0.68–2.09) |
| Current smoking | 11/84 | 15/112 | 1.05 | 1.00 | (0.42–2.35) |
| Use of the following dietary supplements in the former 20 years: | 26/69 | 46/89 | 0.73 | 0.70 | (0.39–1.25) |
| Vitamin supplements | 17/78 | 29/106 | 0.80 | 0.80 | (0.40–1.59) |
| Vitamin and mineral supplements | 16/79 | 27/108 | 0.81 | 0.73 | (0.36–1.47) |
| Aminoacidic supplements | 4/91 | 2/133 | 2.92 | 2.81 | (0.47–16.87) |
| Energy drinks | 7/88 | 11/124 | 0.90 | 0.88 | (0.31–2.51) |
| Selenium-containing supplements | 23/72 | 37/98 | 0.85 | 0.88 | (0.47–1.65) |
| Clinical history | |||||
| Any trauma requesting medical evaluation | 35/60 | 49/86 | 1.02 | 1.14 | (0.64–2.01) |
| Head trauma | 19/76 | 13/122 | 2.35 | 2.61 | (1.19–5.72) |
| Trunk trauma | 9/86 | 8/127 | 1.66 | 1.76 | (0.64–4.85) |
| Arm trauma | 16/79 | 39/96 | 0.50 | 0.52 | (0.27–1.02) |
| Any fracture | 34/61 | 54/81 | 0.84 | 0.85 | (0.49–1.48) |
| Head fracture | 3/92 | 1/134 | 4.37 | 4.07 | (0.40–41.30) |
| Trunk fracture | 6/89 | 10/125 | 0.84 | 0.93 | (0.31–2.73) |
| Arm fracture | 26/69 | 45/90 | 0.75 | 0.75 | (0.41–1.35) |
| Electric shock trauma | 7/88 | 5/130 | 2.07 | 2.09 | (0.62–7.06) |
| Previous Polio vaccine | 41/54 | 66/69 | 0.79 | 0.75 | (0.41–1.35) |
| Previous spinal anesthesia | 24/71 | 36/99 | 0.93 | 0.94 | (0.51–1.74) |
| Ever been blood donor | 24/71 | 37/98 | 0.90 | 0.98 | (0.53–1.84) |
| Any surgery | 76/19 | 113/22 | 0.78 | 0.75 | (0.37–1.53) |
| with general anesthesia | 23/53 | 35/78 | 0.97 | 0.97 | (0.51–1.85) |
| ALS cases in the family | 5/90 | 2/133 | 3.69 | 3.56 | (0.65–19.45) |
a Crude model; b Model adjusted by sex, age, and educational attainment; c Section missing for 28 subjects due to pilot version of the questionnaire. Analysis performed in 202 participants only (68 cases/134 controls); d Recommended alcohol units (two alcohol units in men, one unit in women) used as cutoff points.