Translation and validation of the Italian version of the Wisconsin Stone Quality of Life Questionnaire (I-WISQOL) for assessing quality of life in patients with urolithiasis.

ABSTRACT

BACKGROUND: Urolithiasis is a chronic condition, and it has been associated with a significant negative impact on patients' health-related quality of life (HRQOL). Several tools to assess patients' HRQOL have been validated in Italian, however disease-specific HRQOL instruments are still lacking. We aimed to develop and validate the Italian version of the WISQOL (I-WISQOL) in patients with urolithiasis. METHODS: The Italian version of the WISQOL was developed in a multistep process involving primary translation, back-translation, and pilot testing among a group of patients (N.=10). Patients presenting with urolithiasis were prospectively recruited from the outpatient stone clinics and completed both questionnaire WISQOL and SF-36. Demographic information, as well as medical and surgical data, were obtained through an interview. Internal consistency of the I-WISQOL was obtained with Cronbach's α. Correlation of total scores of the I-WISQOL and SF36 was assessed to determine convergent validity using Spearman Rho. Correlations between clinical variables and results from the I-WISQOL were analyzed to descriptively assess the association of interest. RESULTS: A total of 93 participants were evaluated and completed the Italian version of the I-WISQOL. The I-WISQOL demonstrated excellent internal consistency (Cronbach's α 0.95) and good convergent validity with the validated SF-36 (Spearman Rho r=0.70, P<0.001). Using ANOVA analysis, a significant decline in WISQOL Score was noted with the increasing number of renal colics (P=0.0543), ER visits (P=0.037), number of inpatient hospitalization (P=0.025). At multivariate analysis, worse WISQOL total score was predicted by a greater number of renal colic events (ß=-4.92 [-8.81-1.04], P=0.014) and by a greater number inpatient hospitalization (ß=-7.31 [-14.35 -0.26], P=0.042). CONCLUSIONS: The I-WISQOL is an internally consistent and valid instrument to assess HRQOL in Italian-speaking patients with kidney stones. Its use in clinical practice should be implemented in order to tailor the management of each patient.