QOL-B Is Designed for Non-CF Bronchiectasis and Should Not Be Used in Cystic Fibrosis Bronchiectasis
The QOL-B (Quality of Life Questionnaire-Bronchiectasis) was specifically developed and validated for non-cystic fibrosis bronchiectasis patients and is not applicable to patients with cystic fibrosis who develop bronchiectasis. 1, 2
Evidence Supporting Non-CF Specificity
Development and Validation Population
The QOL-B was explicitly created as "the first disease-specific, patient-reported outcome measure for patients with bronchiectasis" and all validation studies specifically enrolled patients with non-CF bronchiectasis 2
Final psychometric validation involved 542 patients with non-CF bronchiectasis and Gram-negative endobronchial infection, with no CF patients included 1
The instrument contains 37 items across 8 scales (Respiratory Symptoms, Physical, Role, Emotional and Social Functioning, Vitality, Health Perceptions, and Treatment Burden), all validated exclusively in non-CF populations 1, 2
Clinical Guideline Recommendations
The 2019 British Thoracic Society guideline for bronchiectasis consistently refers to QOL-B as a validated tool "specifically for bronchiectasis" in the context of non-CF bronchiectasis monitoring 3
The guideline explicitly distinguishes between "non-CF bronchiectasis" when discussing QOL-B use, indicating it should not be extrapolated to CF populations 3
When discussing quality of life assessment in routine monitoring, the guideline states QOL-B is among validated tools for bronchiectasis but does not extend this recommendation to CF-related bronchiectasis 3
Why CF Requires Different Instruments
Disease-Specific Differences
Cystic fibrosis has fundamentally different pathophysiology, treatment burdens, and psychosocial impacts compared to non-CF bronchiectasis, requiring CF-specific quality of life measures 4
The Cystic Fibrosis Questionnaire (CFQ) is the established disease-specific measure for children, adolescents, and adults with CF, addressing the unique aspects of CF that generic or non-CF bronchiectasis tools cannot capture 4
CF-specific instruments like the CFQoL questionnaire have been validated specifically for CF populations and account for the multisystem nature of CF beyond just bronchiectasis 5
Clinical Implications
For CF Patients with Bronchiectasis
Use validated CF-specific quality of life instruments (CFQ, CFQoL) rather than the QOL-B 4, 5
The QOL-B's validation in non-CF populations means its minimal important difference score of 8.0 points and responsiveness characteristics cannot be reliably applied to CF patients 1
CF patients require assessment tools that capture pancreatic insufficiency, CF-related diabetes, nutritional issues, and other systemic manifestations not addressed in the QOL-B 4
Common Pitfall to Avoid
Do not assume that because a CF patient has bronchiectasis, the QOL-B is appropriate. The underlying disease etiology (CF vs. non-CF) determines which quality of life instrument should be used, not the presence of bronchiectasis alone. Using an unvalidated instrument in CF populations will yield unreliable and potentially misleading data about treatment effects and patient outcomes 1, 2, 4.