Adolescents validly report their exposure to secondhand smoke.

Objective: This study examined the validity of child-reported exposure to secondhand smoke (SHS) and investigated factors, such as child's age, which might affect accuracy of recall.

Study Design And Setting: Participants were drawn from a nonprobability sample of 380 families who completed baseline assessment as part of a randomized trial of an SHS reduction intervention conducted in an urban setting in Southern California. Parents and children (aged 8-13 years) retrospectively reported child's exposure to SHS using timeline followback methodology; reports were compared with child's urine cotinine.

Results: Validity coefficients for parents and children were comparable (r=0.58 vs. r=0.53), but parents recalled three times more exposure than children (2.2 vs. 0.8 cigarettes per day; P<0.001). Regression models predicting cotinine indicated that including child in addition to parent reports resulted in better prediction than either alone.

Conclusion: When there is a choice, parent reports are preferable over child reports because of decreased underreporting. However, child-reported SHS exposure had adequate validity (r>0.50) and might be appropriate in some situations. Researchers might consider collecting both parent and child reports because each made a unique contribution to the prediction of cotinine.