Background: Cystic fibrosis (CF) is a genetic disease affecting more than 160,000 individuals worldwide. Despite improved outcomes with modulator therapies, adults with CF continue to report impaired quality of life (QOL). Some prior studies suggest QOL in CF is driven primarily by symptoms while others indicate stronger correlations between lung function and QOL.
Aims: To examine the relationship between forced expiratory volume in 1st second (FEV1) and QOL among adults with CF.
Methods: We evaluated baseline data from InSPIRe:CF, the first randomized trial of a palliative care intervention to improve QOL in adults with CF. Participants were eligible if they had: ?2 CF-related hospitalizations in the past year and/or ?1 moderate or severe symptom on the Integrated Palliative Care Outcome Scale. The primary exposure was obstruction (FEV1 <70=mild, 40-70=moderate or <40=severe). QOL was measured with the Functional Assessment of Chronic Illness Therapy-Palliative Care QOL score (0-4 scale; 0=worst and 4=best). We used ordinal logistic regression to estimate the association between obstruction and QOL, controlling for modulator therapy, body mass index, and age.
Results: Among 240 participants, the median age was 33 (IQR 27-42), median FEV1 was 73 (IQR 51-89) and 78% were on modulator therapy. Compared to patients with mild obstruction, those with severe obstruction had significantly greater odds of worse QOL (aOR 3.3, 95% CI 1.5-7.3) whereas those with moderate obstruction did not have greater odds of worse QOL (aOR 1.4, 95% CI 0.9-2.4).
Conclusions: In our study of adults with CF, QOL decreased as airway obstruction worsened.