Table 1

Bias in the crude estimation of the E–D association by selected values of the data generating parameters; results from 1000 simulations

Np (E=1)p (R=1)Baseline rate of DInteractionMean βER range*Mean E–D bias range†
Reference scenario
 50000.50.50.03No−0.31; 0.45−0.15; 0.15
Alternative scenarios
 50000.50.50.03Yes−0.98; 0.74−0.24; 0.27
 50000.250.50.03No−0.31; 0.45−0.15; 0.15
 50000.50.50.01No−0.31; 0.45−0.15; 0.16
 50000.50.50.06No−0.31; 0.45−0.14; 0.15
 2500‡0.50.50.03No−0.32; 0.45−0.15; 0.15
 50000.50.10.03No−0.33; 0.45−0.12; 0.07

  • ↵* βER expressed as log(OR).

  • ↵† βDE expressed as log(HR).

  • ↵‡ Results from 2000 simulations.

  • E, exposure; R, risk factor; D, disease.