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. Trial Registry: ClinicalTrials.gov; No.: NCT01232478; URL: www.clinicaltrials.gov.