Recruiting families for an intervention study to prevent second-hand smoke exposure in children

Background: We evaluated the effectiveness of different recruitment strategies used in a study aimed at eliminating/ reducing second-hand smoke (SHS) exposure in Dutch children 0-13 years of age with a high risk of asthma. Methods: The different strategies include: 1) questionnaires distributed via home addresses, physicians or schools of the children; 2) cohorts from other paediatric studies; 3) physicians working in the paediatric field (family physicians, paediatricians and Youth Health Care (YHC) physicians); and 4) advertisements in a local newsletter, at child-care facilities, and day-care centres. Results: More than 42,782 families were approached to take part in the screening of which 3663 could be assessed for eligibility. Of these responders, 196 families met the inclusion criteria for the study. However, only 58 (one third) could be randomised in the trial, mainly because of no interest or time of the parents. The results showed that recruiting families who expose their children to SHS exposure is very challenging, which may be explained by lack of 'recognition' or awareness that SHS occurs in homes. The presence of asthma in the family, respiratory symptoms in the children, and even incentives did not increase parental motivation for participation in the study. Conclusions: The recruitment process for an intervention program addressing SHS exposure in children was considerably more challenging and time consuming than anticipated. Barriers at both a parents level and a doctor's level can be discriminated.