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

Abstract

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.