Validation of the Brazilian Version of the Cambridge Renal Stone Patient-Reported Outcome Measure (Br-CReSP) versus a Generic Questionnaire for Assessing Health-Related Quality of Life in Nephrolithiasis

PURPOSE: No validated tool specifically assesses health-related quality of life (HRQoL) in Brazilian patients with kidney stones. The Cambridge Renal Stone Patient-Reported Outcome Measure (CReSP) is a self-administered questionnaire that evaluates the impact of kidney stones on patients' QoL over the preceding seven days. This study aimed to translate the CReSP into Portuguese, validate it, and compare it with the validated generic SF-12 questionnaire. MATERIALS AND METHODS: The CReSP questionnaire was translated into Portuguese following Guillemin's guidelines. Patients with and without kidney stones completed the Brazilian version of the CReSP (Br-CReSP) and SF-12 questionnaires. Internal consistency, test-retest reliability, discriminant validity, and convergent validity with SF-12 components were evaluated. Logistic regression assessed the discriminant capacity of Br-CReSP and SF-12 components for nephrolithiasis. RESULTS: One hundred patients completed both questionnaires. Internal consistency was high across all domains and the total score (Cronbach's α = 0.92). Test-retest reliability demonstrated strong correlations for all domains and the total score (ICC = 0.94). Discriminant validity was evidenced by significant differences between patients with and without kidney stones, with large effect sizes. Convergent validity was shown by significant inverse correlations between the Br-CReSP and SF-12 (p < 0.001). The Br-CReSP outperformed PCS-12 and MCS-12 in predicting nephrolithiasis (AUC = 0.91 vs. 0.84 and 0.73, respectively). CONCLUSIONS: The validated Br-CReSP outperforms SF-12 in assessing HRQoL in Brazilian patients with kidney stones.