[Validation of the Spanish version of the Revised Cystic Fibrosis Quality of Life Questionnaire in adolescents and adults (CFQR 14+ Spain)]

Abstract

Background: The aim of this study was to assess the validity and reliability of the Spanish version of the revised disease-specific health related quality of life questionnaire for adolescents and adults with cystic fibrosis (CFQR 14+ Spain).

Methods: A total of 43 cystic fibrosis (CF) patients completed the CFQR 14+ Spain. Forced expiratory volume in 1 second, in percentage of predicted - FEV(1) (%)-, number of respiratory exacerbations, 6-minute walk test, Bhalla score (based on computerized tomography of the chest), fat-free mass index, body mass index (BMI), faecal fat and St George's Respiratory Questionnaire were included as measurements of health status.

Results: Ten out of the twelve scales had alpha coefficients above 0.70. Test-retest correlations (Spearman) ranged from 0.49 to 0.95 and they were significant in all scales. Intraclass correlations ranged from 0.47 to 0.95 (ten out of the twelve scales were >0.70) forty out of the fifty ítems have correlations between items and scale above 0.70. All the CFQR+14 scales, except the digestive symptoms scale, discriminated significantly between patients with mild, moderate and severe disease (according to FEV(1) (%)). Other respiratory parameters also discriminated significantly between patients with mild-moderate and severe disease. Only some scales discriminated significantly between nourished and malnourished patients. All of the scales met standards for floor effects (<15% of the responders with the lowest score) but not for ceiling effects (only five out of the twelve).

Conclusion: The Spanish CFQR14+ (Spain) is a reliable and valid instrument for measuring the health-related quality of life in Spanish adolescents and adults with CF, though with the exception of a few of its subscales.