Validation of the German translation of the Quality of Life-Bronchiectasis (QoL-B) questionnaire: data from the German Bronchiectasis Registry PROGNOSIS

Objective Bronchiectasis is associated with high symptom burden and reduced health-related quality of life (QoL). We aimed to validate the German translation of the Quality of Life Questionnaire-Bronchiectasis (QoL-B) questionnaire.

Methods We investigated associations between QoL-B scales and symptom burden, disease severity and psychometric measures within the German Bronchiectasis Registry. The German translation of the QoL-B V.3.0, which uses 8 scales (Respiratory Symptoms[RS], Physical Functioning[PF], Vitality[V], Role Functioning[RF], Health Perceptions[HP], Emotional Functioning[EF], Social Functioning[SF] and Treatment Burden[TB]), was routinely applied at baseline. Floor and ceiling effects (> 15% of participants), internal consistency of (Cronbachʼs α) and minimal clinically important difference (MCID; 0.5 SD of the mean) were investigated.

Results Between Jun 2015 and Sep 2018, 1155 subjects were recruited from 38 centers. Here, data from 1000 validated datasets are shown (median age 61 years, 59% female; most common etiologies: idiopathic[36%], postinfectious[21%], COPD[15%]). At baseline, 65[TB] to 90%[RF] of subjects completed QoL-B scales. All scales were significantly associated with higher MRC dyspnea scores (p < 0.001, each). Regular sputum production and increased average daily sputum volume were associated with lower scores in RS, HP, SF and TB (p < 0.001, each). Lower scores in RS, PF, RF, HP (p < 0.001, each) and TB (p = 0.015) were observed with declining FEV1 categories. Lower scores in all scales were associated with exacerbation history (p < 0.05, each), prior hospitalization and increasing disease severity as determined by Bronchiectasis Severity Index (BSI) categories (p < 0.01, each; except EF). Pseudomonas aeruginosa infection was associated with chronic sputum production, regular airway clearance and pharmacological therapy, prior thoracic surgery and radiological severity (p < 0.01, each), as well as lower scores in RS, PF, HP, TB (p < 0.01, each) and RF (p = 0.02). No floor or ceiling effects were observed. Internal consistency for each scale was excellent (Cronbachʼs α 0.867 – 0.888). MCID ranged from 10 [RF] to 15 points [PF].

Conclusion Our analysis confirms that the QoL-B is a feasible and reliable tool to determine QoL in German bronchiectasis patients.