Table 2.

Results of regression models with the outcome log10 toenail As (μg As/g) for a participant of median age (27 years)

PredictorsEstimateSE*95% CIP
Model 1: Fixed effects
    Intercept−0.1550.047−0.183 to −0.089<0.0001
    Age−0.0050.005−0.02 to 0.010.38
    GSTT1(−)0.0760.036−0.001 to 0.1540.03
    Age × log10 drinking water As (μg/L)0.0100.0040.0001 to 0.020.02
    Log10 drinking water As (μg/L)§0.1910.012<0.0001
Model 2: Gene-environment interaction
    Intercept−0.1350.051−0.169 to 0.058<0.001
    Age−0.0100.005−0.025 to 0.0050.28
    GSTT1(−)−0.0640.053−0.181 to 0.0360.41
    Age × log10 drinking water As (μg/L)0.0100.0050.002 to 0.020.02
    GSTT1(−) × log10 drinking water As (μg/L)0.1250.0350.064-0.20.001
    Log10 drinking water As (μg/L)§0.1770.013<0.0001
  • NOTE: The estimates for drinking water concentrations are valid above 2 μg As/L.

  • * SEs estimated via bootstrap (500 resampled statistics).

  • Nonparametric bootstrap bias-corrected accelerated 95% CIs.

  • Intercept is for median age of 27 years and the estimate is for 5-year increments.

  • § Estimates of drinking water effect are based on fully parametric model approximating the nonparametric effect depicted in Figs. 2 and 4 for drinking water above 2 μg As/L.