not quite significantp = 0.08
18 ) but in a test for such interaction, adjusting for “without radon” covariates, and also adjusting for quartiles of cumulative DEMS_REC1 lagged 15 years, the interaction term was not quite significant ( p = 0.08) and, more importantly, tests for an effect of REC exposure appeared to be little impacted by whether or not smoking was entered as a main effect and in an interaction term or only as a main effect.