Can parents of children with cancer accurately report their child's passive smoking exposure?

INTRODUCTION: This study examined whether children with cancer are exposed to measurable levels of passive smoke as assessed by parent report and laboratory measures of urine cotinine, an established biomarker of passive smoke exposure (PSE). It also determined whether parents/caretakers of young cancer patients can provide valid reports of their child's PSE during the child's treatment, by examining their association with urine cotinine measures.
METHODS: Participants included 124 parents of a child with cancer who lived with at least one adult smoker in the home and was exposed to tobacco smoke in the home and/or car. Eligible patients were younger than 18 years of age, were receiving active treatment for cancer at a large pediatric oncology institution, were at least 30 days postdiagnosis, and did not smoke. Parents provided information about smoking and their child's PSE by responding to a series of questionnaires. Patients provided urine samples for cotinine analyses.
RESULTS: Findings showed that parents provided valid short-term accounts of their child's PSE in the context of their child's cancer treatment. Parent reports of PSE showed moderately strong positive relationships with urine cotinine levels which were stronger for reports provided by parents who smoked compared with nonsmoking parents. DISCUSSION: Parent reports of PSE were validated by positive and significant associations with urine cotinine. Reports provided in the context of possible verification by biomarker assays can provide sufficiently accurate estimates of PSE to serve as outcome measures for clinical research and clinical care in a pediatric cancer setting.