Validation of the French version of the Wisconsin Quality of Life (WISQOL) questionnaire for patients with nephrolithiasis.

Introduction: The Wisconsin Stone Quality of Life (WISQOL) questionnaire has been recently developed to objectively assess quality of life (QOL) in patients with nephrolithiasis. However, a French version of the questionnaire was lacking. Therefore, the aim of the present study was to develop and validate the French version of this tool.

Methods: The French version of the WISQOL (F-WISQOL) was developed in a multistep process involving primary translation, back-translation, and pilot testing among a group of patients (n=12). Nephrolithiasis patients from two tertiary care institutions were recruited into this study and completed the following questionnaires: the medical history form and either the WISQOL or F-WISQOL. Internal consistency was assessed using Cronbach's α, and inter-domain associations were evaluated using Spearman's rank correlation (r). One-way ANOVA was used to compare scores from the two groups (WISQOL and F-WISQOL).

Results: A total of 210 patients were enrolled in this study: 68 in the WISQOL group and 148 in the F-WISQOL group. Internal consistency was high for all domains in both groups (F-WISQOL: 0.924-0.970; WISQOL: 0.888-0.965). No statistically significant difference was found between the two groups' scores. Inter-domain association, measured by Spearman correlation, was moderate to very strong between all the domains in the F-WISQOL. Values ranged from r=0.676-0.915, with acceptable correlation between D1, D2, and D3, but weaker correlation between D4 (vitality) and the three other domains (r=0.676-0.729).

Conclusions: In the present study, the French version of the WISQOL questionnaire was validated at two academic institutions.