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P42 Evaluating the impact of triple combination modulators on medication adherence in cystic fibrosis
  1. Sharon Sutton1,
  2. Paul McNally2,
  3. Moninne Howlett1,
  4. John Hayden2
  1. 1Children’s Health Ireland at Crumlin
  2. 2RCSI


Aim To measure the impact of introduction of triple combination modulator (TCM) therapy on adherence to other cystic fibrosis (CF) therapies.

Method This study is a multi-site non-interventional study of clinical outcomes in CF patients prescribed TCM across 8 clinical sites in Ireland and the UK over 2 years. The study will be conducted over two phases based on TCM approval: 1. 12+ arm (patients 12 years and older), 2. 6+ arm (patients 6-11 years). The effect of the potential drop-off in adherence to TCM is unknown and this knowledge gap will be examined using three methods; self-reported questionnaires (SRQ) [e.g. Treatment adherence questionnaire (TAQ) and Adherence barrier questionnaire (ABQ)]; pharmacy refill data (to calculate Medication Possession Ratio); and electronic devices such as Medication Electronic Monitoring System (MEMS®). Self-report tools and pharmacy refill data will be collated for all participants but due to high cost MEMS will be offered to a subset only (approx. 80 participants).

Results To date, 113 participants have been recruited to the 12+ arm. Recruitment and data collection is ongoing. Preliminary analysis of Medication Possession Ratio (n=5) demonstrated that baseline adherence to hypertonic saline, azithromycin, enzymes and Pulmozyme® was low to moderate, further decreasing after TCM introduction. No change for enzymes was found. Adherence to modulators was high, with further increases seen after TCM introduction. Self-report questionnaires (TAQ and PTP) were reviewed for a random 10% of current recruits (n=11). The mean Overall Adherence Index was 90.2%. At 6-month time point, 100% TCM adherence was reported. Airway clearance was the most frequently overlooked treatment with a 10.6% reduction in adherence from baseline to 6 months. Initial recruitment for MEMS® was high (95% recruitment target met) with 60% of participants remaining on the study. Average ‘taking adherence’ using MEMS® for was 78.2% and 82% for Kaftrio® (n=11) and Kalydeco® (n=10) respectively. Overall adherence to TCM using MEMS® was 78.9%.

Conclusion These early preliminary results suggest that adherence to TCM is overestimated in SRQs and pharmacy data in comparison to MEMS®. These trends are similar to those shown in previous studies [1-3]. As a result of the high dropout rate a feedback form has been developed to gain a better insight into the reasons why continued participation is low. Recruitment and data collection is ongoing. 6+ arm is due to commence recruiting in Q4 2021.


  1. Mehta Z, Kamal KM, Miller R, Covvey JR, Giannetti V. Adherence to cystic fibrosis transmembrane conductance regulator (CFTR) modulators: analysis of a national specialty pharmacy database. J Drug Assess 2021;10:62-67.

  2. Stirratt MJ, Dunbar-Jacob J, Crane HM, Simoni JM, Czajkowski S, Hilliard ME, et al. Self-report measures of medication adherence behavior: recommendations on optimal use. Translational Behavioral Medicine 2015;5:470-482.

  3. Siracusa CM, Ryan J, Burns L, Wang Y, Zhang N, Clancy JP, et al. Electronic monitoring reveals highly variable adherence patterns in patients prescribed ivacaftor. Journal of Cystic Fibrosis: Official Journal of the European Cystic Fibrosis Society 2015;14:621-626.

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