Background Newborn screening (NBS) for cystic fibrosis (CF) has been available throughout the UK since 2007. Such screening is only justified if it improves outcome. NBS offers the potential for early intervention in order to preserve lung function and nutritional status. There are few, if any, ways of satisfactorily monitoring such babies non-invasively. To date the feasibility of recruiting newborn babies to invasive studies within the first few weeks following diagnosis is unknown.

Aim To assess the feasibility of recruiting and retaining infants diagnosed by NBS to an invasive observational study, prior to proposing an interventional study.

Methods All children presenting from the CF NBS programme from six centres comprising the London CF Collaboration (LCFC: Great Ormond St, Royal Brompton, Kings College, Royal London, Lewisham University and Epsom and St Helier's Hospitals) are being invited to participate in a study which involves infant lung function under sedation at ∼3 and 12 months plus a combined CT, bronchoscopy and BAL under GA at ∼12 months, within 3 weeks after the lung function test.

Results Since commencement of this study, 63 infants have screened positive for CF of whom five were ineligible (co-existent morbidities or moving away from area). Of the 58 eligible babies, seven have either declined (6) or withdrawn (1), eight families are currently considering participation and 43 have consented to participate. Infant lung function at 3 months has been undertaken in 43 babies (mean age at test 10.8 (SD 2.4) weeks. Of the 16 babies that have now reached one year of age, all have completed their follow-up lung function test and 15 have had their CT and BAL, with one awaiting an appointment. To date, parents' attitudes to taking part in this study have been universally positive.

Conclusions Despite initial concerns from some reviewers regarding the ability to recruit and retain families whose infants have been diagnosed with CF by NBS into clinical studies with invasive outcomes, these preliminary data indicate that it is possible to recruit a high proportion of babies to such a study. These results suggest that future interventional studies will be feasible.