Measuring environmental tobacco smoke exposure in infants and young children through urine cotinine and memory-based parental reports: empirical findings and discussion.

OBJECTIVE This study examined the reliability and potential biases of two urine collection methods from which cotinine measures were obtained and the validity of memory-based parental reports of their children's exposure to environmental tobacco smoke (ETS). DESIGN Structured interviews were conducted with mothers of infants and young children to obtain memory-based estimates of recent ETS exposure. Urine samples were collected through standard and cotton roll collection methods for cotinine analysis. SETTING All interviews took place at an off-campus research facility. Urine samples were collected at the study office or the subjects' homes. PARTICIPANTS Mothers were recruited from San Diego county sites of the Women, Infants, and Children (WIC) Supplemental Food and Nutrition Program. Sample 1 (infants) consisted of eight boys and eight girls aged 1-44 months (mean = 12.6 months). Sample 2 (children) included 10 boys and 10 girls aged 3-8 years (mean = 61.2 months). MAIN OUTCOME MEASURES Urine cotinine and memory-based parent reports of ETS exposure from structured interviews. RESULTS There was overall high reliability for urine cotinine measures and no effect of collection method on urine cotinine levels. Memory-based reports obtained from smoking mothers showed moderately strong and consistent linear relationships with urine cotinine measures of their infants and children (r = 0.50 to r = 0.63), but not for reports obtained from non-smoking mothers. CONCLUSIONS Memory-based parental reports of short-term ETS exposure can play an important role in quantifying ETS exposure in infants and children.