Table 4

Analyses of cumulative estimated exposure to lead and ALS case status in women

Controls N (%)Cases N (%)OR (95% CI)*aOR (95% CI)†
No lag (n=60 105)
 No exposure44 867 (75.47)495 (75.80)1.00 (Ref)1.00 (Ref)
 Ever exposure (µmol/L)‡14 585 (24.53)158 (24.20)0.99 (0.82 to 1.18)1.01 (0.83 to 1.21)
 <17.403566 (6.00)37 (5.67)0.95 (0.68 to 1.33)0.94 (0.66 to 1.34)
 17.40–72.893663 (6.16)39 (5.97)0.97 (0.70 to 1.34)1.03 (0.74 to 1.31)
 >72.897356 (12.37)82 (12.56)1.01 (0.80 to 1.28)1.03 (0.80 to 1.31)
 Test for trend1.00 (0.97 to 1.04)1.00 (0.97 to 1.04)
5-year lag
 No exposure46 938 (78.95)514 (78.71)1.00 (Ref)1.00 (Ref)
 Ever exposure (µmol/L)‡12 514 (21.05)139 (21.29)1.00 (0.84 to 1.20)1.02 (0.85 to 1.24)
 <17.403675 (6.18)40 (6.13)1.00 (0.73 to 1.39)0.99 (0.70 to 1.39)
 17.40–72.893678 (6.19)44 (6.74)1.10 (0.81 to 1.50)1.14 (0.83 to 1.56)
 >72.895161 (8.68)55 (8.42)0.98 (0.74 to 1.30)1.00 (0.75 to 1.34)
 Test for trend1.01 (0.95 to 1.07)1.02 (0.95 to 1.08)
10-year lag
 No exposure47 637 (80.13)520 (79.63)1.00 (Ref)1.00 (Ref)
 Ever exposure (µmol/L)‡11 815 (19.87)133 (20.37)1.04 (0.86 to 1.26)1.04 (0.85 to 1.27)
 <17.403544 (5.96)39 (6.73)1.02 (0.74 to 1.36)1.00 (0.71 to 1.41)
 17.40–72.893545 (5.96)44 (6.74)1.15 (0.84 to 1.56)1.17 (0.85 to 1.61)
 >72.894726 (7.95)50 (7.66)0.98 (0.73 to 1.31)0.98 (0.72 to 1.32)
 Test for trend1.00 (0.93 to 1.07)1.01 (0.94 to 1.08)
  • *Controls were individually matched to cases on age and sex.

  • †Models adjusted for SES and residential location.

  • ‡Cumulative estimated exposure=[(level of exposure)*(probability of exposure)/100]*(days employed).

  • ALS, amyotrophic lateral sclerosis; aOR, adjusted OR; SES, socioeconomic status.