Validity of self-reports and descriptive and analytical conclusions: the case of cigarette smoking by adolescents and their mothers

Biochemical and self-report measures of cigarette smoking were obtained from a study population of eight-grade students who were enrolled in the Guilford County, North Carolina, school system during May 1980 and their mothers. A group of 386 adolescents provided self-reports before awareness of the biochemical evaluation, while a group of 1439 mothers encompassed unaware and aware observational conditions. Substantial crude agreement was found between carbon monoxide in alveolar air and questionnaire responses on recency of smoking, and the biochemical and self-report measures yielded similar descriptive estimates of smoking. Sensitivity and specificity for mothers, and specificity for the adolescents, exceeded 90%. Although only 64% of the adolescents classified as smokers according to the biochemical measure reported that they were smokers, most correlates of their smoking behavior were the same regardless of the measure that was used.