Table 3 Age- and sex-adjusted Mantel-Haenszel relative risk (RR-MH) with 95% confidence interval (CI) of amyotrophic lateral sclerosis according to long-term consumption of drinking water with Se content ≥1 μg/l vs. <1 μg/l, Reggio Emilia municipality, northern Italy, 1995-2006
| Males | Females | Total | |||||
|---|---|---|---|---|---|---|---|
| Age | High Se | Low Se | High Se | Low Se | High Se | Low Se | |
| 40-54 | cases | 1 | 6 | 1 | 1 | 2 | 7 |
| controls | 1 | 13 | 0 | 4 | 1 | 17 | |
| 55-69 | cases | 3 | 6 | 0 | 4 | 3 | 10 |
| controls | 4 | 14 | 0 | 8 | 4 | 22 | |
| ≥70 | cases | 2 | 12 | 1 | 4 | 3 | 16 |
| controls | 0 | 28 | 1 | 9 | 1 | 37 | |
| Total | cases | 6 | 24 | 2 | 9 | 8 | 33 |
| controls | 5 | 55 | 1 | 21 | 6 | 76 | |
| RR-MH 3.3 (95% CI 1.0 - 11) | |||||||