title: Validity of the Spanish version of the Chronic Liver Disease Questionnaire (CLDQ) as a standard outcome for quality of life assessment.
abstract: The Chronic Liver Disease Questionnaire (CLDQ) measures the impact on quality of life of chronic liver diseases, regardless of underlying etiology. The aim of this study was to develop a Spanish version of the CLDQ, and to assess its acceptability, reliability, validity, and sensitivity to change. The forward and back-translation method by bilingual translators, with expert panel and pilot testing on patients, was used for the adaptation. The final version was self-administered, together with the Short Form-36 Health Survey (SF-36), on 149 consecutive patients with chronic liver disease. Child-Turcotte-Pugh scores were evaluated by a physician. To assess reproducibility and responsiveness the CLDQ was readministered to a subsample of stable patients and to those who had received a liver transplant. Validity was evaluated via exploratory factor analysis, the CLDQ pattern across severity groups, and correlation coefficients with "itching" and SF-36 scores. Cronbach's alpha and Intraclass Correlation Coefficient for CLDQ global score were 0.93 and 0.90, respectively, demonstrating good reliability. Validity was supported by correlations of the CLDQ with SF-36 and "itching," and CLDQ severity gradient (global score means were 5.5, 5.2, 5.0, and 4.5 in patients with no cirrhosis, cirrhosis Child-Turcotte-Pugh A, B, and C, respectively; P = 0.012). Responsiveness was shown by a high CLDQ improvement in patients who had received liver transplant (mean change = -1.4; P < 0.001). In conclusion, the Spanish CLDQ is reliable, valid, responsive, and equivalent to the original. These findings support its use as a standard outcome for patients with chronic liver diseases within the whole severity range, from "no cirrhosis" to transplant recipients, both in Spanish and international studies.
authors.affiliation: Health Services Research Unit, Institut Municipal d'Investigació Mèdica, Barcelona, Spain. mferrer@imim.es
authors.forename: Montserrat
authors.initials: M
authors.lastname: Ferrer
authors.forename: Juan
authors.initials: J
authors.lastname: Córdoba
authors.forename: Olatz
authors.initials: O
authors.lastname: Garin
authors.forename: Gemma
authors.initials: G
authors.lastname: Olivé
authors.forename: Montserrat
authors.initials: M
authors.lastname: Flavià
authors.forename: Victor
authors.initials: V
authors.lastname: Vargas
authors.forename: Rafael
authors.initials: R
authors.lastname: Esteban
authors.forename: Jordi
authors.initials: J
authors.lastname: Alonso
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011336:Probability; D011788:Quality of Life; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution; D018434:Sickness Impact Profile; D013030:Spain; D011795:Surveys and Questionnaires / Q000592:standards*; D014177:Translations