Measuring quality of life in end-stage renal disease - Transcultural adaptation and validation of the specific Kidney Disease Quality of Life questionnaire

End-stage renal disease has an important impact on the patients' daily life, which can be measured by quality of life questionnaires. The objective of this work was to adapt the Kidney Disease Quality of Life questionnaire (KDQoL) into French and to determine its basic psychometric properties, i.e. validity and reliability. The KDQoL consisted of 8 generic dimensions and 11 specific dimensions. The questionnaire was translated several times independently, and then submitted to a committee of professionals. The study of the measurement properties was carried out near 68 dialysis patients. KDQoL is valid and reproducible, and has properties comparable to the original instrument: missing items proportion of 5.5%, limited floor and ceiling effects (except for 4 dimensions), Cronbach alpha coefficient varying from 0.64 to 0.92 (except for 2 dimensions), test-retest coefficient greater than 0.67 (except for 3 dimensions), and the items of KDQoL were better correlated with their dimension than with other dimensions (except for 2 dimensions). Correlations between the generic and the specific scores showed the absence of redundancies between specific and generic dimensions. Thus the French version has comparable properties to the original KDQoL. This questionnaire can be used to measure the quality of life of the dialysis patients. It constitutes a good tool in clinical research, allowing international comparisons. (C) 2007 Elsevier Masson SAS et Association Societe de Nephrologie. Tous droits reserves.