Clustered randomized controlled trial of a clinic-based problem-solving intervention to improve adherence in adolescents with cystic fibrosis

Background: In Cystic Fibrosis (CF), adherence to pulmonary medications is about 50% and decreases during adolescence. Effective interventions have not been integrated into CF care. This effectiveness study tested a brief, clinic-based behavioral intervention to improve adherence. Methods: iCARE (I Change Adherence and Raise Expectations) was a pragmatic, clustered, 2-arm randomized controlled trial at 18 CF Centers. 607 adolescents with CF, ages 11-20 years, participated. Centers were randomized to IMPACT (n = 9; 300 adolescents), a brief problem-solving + education intervention, or standard care (SC; n = 9; 307 adolescents). IMPACT was delivered during a regularly scheduled clinic visit by a member of the clinical care team. The primary outcome was composite pulmonary medication possession ratio (cMPR); secondary endpoints were lung function, Body Mass Index percentile, courses of IV antibiotics, and health-related quality of life at 12 months. Results: Effectiveness of the intervention was tested using mixed models, generalized estimating equations comparing IMPACT to SC. Fifty-eight percent of problem-solving sessions targeted barriers to airway clearance, exercise or nutrition, while 18% addressed pulmonary medications. Average intervention fidelity score was 67% (SD = 14%; Range = 25-100%). No significant intervention effects were found for cMPR or any of the secondary outcomes compared to SC. Conclusions: The IMPACT intervention did not improve medication adherence or health outcomes over 12 months. Challenges to implementing the intervention as intended during busy clinic visits were identified. (C) 2019 Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society.