Quality of Life Gauged With Patient-Reported Outcome Measure in Cystic Fibrosis

The Q-Life app for patients with cystic fibrosis (CF), which uses personalized patient-reported outcome measures (PROM) to assess quality of life (QoL), is a reliable, valid, and sensitive tool for assessing QoL in individuals with CF, according to study findings published in eClinicalMedicine.

Researchers sought to validate the Q-Life app for individuals with CF, a unique, short, personalized electronic QoL assessment using PROMs.

The Q-Life app was developed in collaboration with adults with CF as well as parents of children with CF who were recruited by the Dutch Cystic Fibrosis Foundation during outpatient visits to CF clinics of the University Medical Center (UMC) Utrecht in the Netherlands. The app asks users to choose and rank 3 to 5 items (associated with a predefined list of categories) important to their quality of life. Users then use a 5-point Likert scale to score the degree to which CF limits them in these areas. The app also collects demographic data.

To validate the app, researchers conducted a 2-stage study to evaluate psychometric properties, first with a single-center cross-sectional study between September 2019 and September 2021 followed by a prospective cohort study between September 2021 and September 2022.

The study included 223 participants (median [range] age, 24 [12.0-58.0] years). Among all participants, 43% reported 3 personal quality of life items, 29% reported 4, and 28% reported 5 items, resulting in a total of 858 self-described quality of life items. The predefined categories most frequently associated with these items were: social activities, physical exercise and sport, and work and education.

The cross-sectional study included 89 participants; among those, 27 were clinically stable and were included in the test-retest reliability assessment. When at least 3 personal quality of life items were described (n=223), Cronbach’s alpha was 0.83 (internal consistency). When at least 4 items were described, Cronbach’s alpha was 0.87, and reached 0.90 when 5 items were described.

Researchers noted strong scores for test-retest reliability (intraclass correlation coefficient, 0.90; 95% CI, 0.65-0.92; P <.001) of quality of life.

Quality of life scores were associated with CF questionnaire-revised (CFQ-R) respiratory domain scores (ρ [population correlation] =0.57), overall CFQ-R scores (ρ =0.71), and forced expiratory volume in 1s (FEV₁) (ρ =0.41) (all P <.001). Association with FEV₁ shows participants with better lung function reported higher quality of life scores. Researchers found no substantial impact of sex or age on these associations.

The cohort study (assessing sensitivity to detect change) included 173 participants at baseline measurement, 122 participants at 3 months, and 123 participants at 6 months. Overall, there was an overlap of 39 individuals who participated in both the cross-sectional and cohort studies.

After 3 months of elexacaftor/tezacaftor/ivacaftor treatment, QoL scores improved from 65.0 (IQR, 45.0-63.3) at baseline to 84.2 (IQR, 75.0-95.0) and after 6 months scores improved to 87.5 (IQR, 75.0-100.0). These scores were comparable to CFQ-R respiratory domain scores.

Study limitations include the cross-sectional observational design, an overlap between the timing of the study and the COVID-19 pandemic, and the lack of follow-up measurements for almost one-third of cohort study participants.

“[T]his first validation study showed that the Q-Life app is a reliable, valid and sensitive personalized ePROM to assess all aspects of quality of life that really matter to individuals with CF,” the study authors concluded. “This patient-centered approach could provide important advantages over generic and disease-specific PROMs in the era of personalized medicine and value-based healthcare.”