A randomized trial of parental behavioral counseling and cotinine feedback for lowering environmental tobacco smoke exposure in children with asthma: results of the LET'S Manage Asthma trial.
BACKGROUND
Secondhand tobacco smoke exposure impairs the control of pediatric asthma. Evidence of the efficacy of interventions to reduce children's exposure and improve disease outcomes has been inconclusive.


METHODS
Caregivers of 519 children aged 3 to 12 years with asthma and reported smoke exposure attended two baseline assessment visits, which involved a parent interview, sampling of the children's urine (for cotinine assay), and spirometry (children≥5 years). The caregivers and children (n=352) with significant documented exposure (cotinine≥10 ng/mL) attended a basic asthma education session, provided a third urine sample, and were randomized to the Lowering Environmental Tobacco Smoke: LET'S Manage Asthma (LET'S) intervention (n=178) or usual care (n=174). LET'S included three in-person, stage-of-change-based counseling sessions plus three follow-up phone calls. Cotinine feedback was given at each in-person session. Follow-up visits at 6 and 12 months postrandomization repeated the baseline data collection. Multivariate regression analyses estimated the intervention effect on the natural logarithm of the cotinine to creatinine ratio (lnCCR), use of health-care services, and other outcomes.


RESULTS
In the sample overall, the children in the LET'S intervention had lower follow-up lnCCR values compared with the children in usual care, but the group difference was not significant (β coefficient=-0.307, P=.064), and there was no group difference in the odds of having>one asthma-related medical visit (β coefficient=0.035, P=.78). However, children with high-risk asthma had statistically lower follow-up lnCCR values compared with children in usual care (β coefficient=-1.068, P=.006).


CONCLUSIONS
The LET'S intervention was not associated with a statistically significant reduction in tobacco smoke exposure or use of health-care services in the sample as a whole. However, it appeared effective in reducing exposure in children at high risk for subsequent exacerbations.


BACKGROUND
ClinicialTrials.gov; No.: NCT00217958; URL: clinicaltrials.gov.
Wilson
Sandra R
SR
Department of Health Services Research, Palo Alto Medical Foundation Research Institute, Palo Alto, CA. Electronic address: Wilsons@pamfri.org.
Farber
Harold J
HJ
Section of Pediatric Pulmonology, Baylor College of Medicine, Houston, TX.
Knowles
Sarah B
SB
Department of Health Services Research, Palo Alto Medical Foundation Research Institute, Palo Alto, CA.
Lavori
Philip W
PW
Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA.
D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D003367:Cotinine / Q000652:urine*; D003376:Counseling; D004781:Environmental Exposure / Q000009:adverse effects; D005246:Feedback; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D010287:Parent-Child Relations; D010290:Parents / Q000523:psychology*; D012307:Risk Factors; D016540:Smoking Cessation; D014028:Tobacco Smoke Pollution / Q000009:adverse effects* / Q000517:prevention & control*
D014028:Tobacco Smoke Pollution; D003367:Cotinine