Table 2

Unadjusted and adjusted ORs of upper tertile hypothyroidism prevalence according to fluoride levels in drinking water

ORFluoride level OR 95% CI
Unadjusted
 Maximum fluoride >0.7 mg/L1.4521.268 to 1.662
 Maximum fluoride >0.3, ≤0.7 mg/L1.7111.439 to 2.034
Maximum fluoride ≤0.3 mg/L
Adjusted*
 Maximum fluoride >0.7 mg/L1.6211.379 to 1.904
 Maximum fluoride >0.3, ≤0.7 mg/L1.3711.120 to 1.679
Maximum fluoride ≤0.3 mg/L
  • *Adjusted for proportion of women registered with the practice, proportion of patients over 40 years old registered with the practice, Index of Multiple Deprivation. C-index=0.82.