Abstract: | Two independent samples of pregnant smokers were interviewed about their cigarette smoking and were tested with biochemical markers at the beginning and end of their pregnancies. Participants were mainly unmarried, racial minorities (chiefly Hispanic), and residents of the inner city. Phi coefficients between self‐reported and chemical indicators ranged from .42 to .74. Contrary to expectations, the self‐report/biochemical‐measure correlations were higher at the end than at the beginning of the pregnancy term. The higher end‐of‐term correspondence between self‐report and chemical indicators likely reflected better reliability of the measures, when taken at term. The results are in accord with earlier research with other populations, indicating adequate validity for self‐reported smoking. |