Psychometric Properties of the Kidney Disease Quality of Life–36 Questionnaire (KDQOL-36™)

Abstract

The Kidney Disease Quality of Life-36 Questionnaire (KDQOL-36™), modified by RAND, has been widely used for measurement of quality of life among hemodialysis or peritoneal dialysis patients. The purpose of this study was to refine and evaluate, by using confirmatory factor analysis, the structure of the KDQOL-36™ when the questionnaire was used to evaluate chronic kidney disease patients in Stages 1 to 5 in Taiwan. The psychometric properties of the translated version were determined among Mandarin-speaking adults (N = 428). Because the sample data did not fit the hypothetical model, one item was deleted and nine error terms were estimated. After improving the model fit, the modified model was presented as follows: χ(2) = 1390.903, χ(2)/df = 2.711, p < .001, goodness-of-fit index = .833, adjusted goodness-of-fit index = .806, root mean square error of approximation = .063. According to the study results, the researchers suggest that because of content overlap, some items may be deducted from the KDQOL-36™.

Measurement properties of patient-reported outcome measures (PROMs) used in adult patients with chronic kidney disease: A systematic review

“…Three disease-specific PROMs were used in pre-dialysis populations namely the: Agarwal [32], KDQOL-36 [33, 34] and KDQOL-SF [35, 36]. Although the studies in this section measured estimated glomerular filtration rates (eGFR), there was significant disparity in their description of patients at this stage of CKD.…”

“…Although the studies in this section measured estimated glomerular filtration rates (eGFR), there was significant disparity in their description of patients at this stage of CKD. Three studies described patients as 'non-dialysis' [32], 'mild-to-moderate' CKD patients [34] and ESRD patients [36] respectively, while only the studies by Chao et al [33] and Abd Elhafeez [35] formally categorized patients into CKD stages. None of the studies validated PROMs separately by stage of CKD pre-dialysis.…”

“…Strong evidence for internal consistency was found [33] and there was moderate evidence for hypothesis testing [33, 34]. Structural validity was rated as 'indeterminate' [33]. …”

“…Six validation studies reported content validity indexes (CVI) [33, 38, 49, 53, 77, 82] and of these only Suet-Ching [49] reported patient involvement in the process of content validation.…”

“…The translations conducted by 20 studies [33, 35, 39, 42, 44–46, 48, 51, 53, 57, 65, 72, 77, 85, 88, 92, 94, 96, 102] were rated as good, while the translations by 4 studies [66, 67, 82, 91] were rated as fair and 1 translation was rated as poor [79]. …”