Supporting adherence to the cystic fibrosis regimen: Development and validation of The Daily Care Check-In (DCC)

Background: The cystic fibrosis (CF) regimen is time-consuming and burdensome leading to barriers to self-management. This mixed-methods study developed the Daily Care Check-in (DCC) that is specific to the barriers faced by people with CF (PWCF) and evaluated its validity.

Methods: Qualitative methods were used to identify barriers to self-management and develop items, with "think aloud" cognitive interviews conducted to refine the items. A multisite, cross-sectional study was conducted to test the internal consistency, test-retest reliability, and validity of the DCC scores, comparing them to objective medication adherence (composite medication possession ratio (cMPR)) and psychosocial measures (self-efficacy, medication beliefs, executive functioning, depressive and anxiety symptoms, treatment burden, and treatment complexity).

Results: The DCC (18 items) includes two scales: Occurrence (score range 0-18) and Interference (score range 0-90). 405 participants completed the DCC, 344 (85 %) completed the survey, and 365 (90 %) had a cMPR calculated. On average, 6.8 barriers were reported (SD = 4.2 Occurrence Scale), and the Interference Scale had a mean score of 18.4 (SD = 14.0). Reliability was acceptable to good. cMPR was negatively correlated with the DCC (rho=-0.26, Occurrence and rho = -0.31, Interference, p-values<0.0001). A priori hypotheses between the DCC and the other measures were supported and demonstrated construct validity.

Conclusions: This study provides evidence supporting the validity of the DCC for assessing the presence and impact of barriers to CF self-management, including medication adherence. Formal screening of self-management barriers (e.g., using the DCC) should be considered to facilitate conversations with the care team and identify tailored interventions to support CF self-management.