Validation of Visual Prostate Symptom Score (VPSS) in Brazilian Sample Population

Abstract

PURPOSE: The aim of the study was to evaluate the reliability and validity of the Visual Prostate Symptom Score (VPSS), its correlation with the International Prostate Symptom Score (IPSS), and the time required and need for help when completing the instrument. We also aimed to identify variables associated with difficulty completing these instruments. DESIGN: Longitudinal, prospective correlational study. SUBJECTS AND SETTING: The target population was Brazilian men from different cities within the state of São Paulo with lower urinary tract symptoms followed in urological consultation at a university hospital during October 2017. The sample comprised 59 patients with a mean age of 66.53 years. METHODS: Reliability of the VPSS was evaluated using a test-retest approach and its convergent validity with the IPSS. Cronbach α coefficient was also calculated. Both questionnaires were self-administered and, in case of difficulty of comprehension, assistance was provided. RESULTS: Mean completion time of the IPSS was 6.56 minutes and for VPSS was 5.02 minutes. The variables skin color and educational level were associated with the difficulty in completing the IPSS and for comprehending meaning of the VPSS pictograms. Internal consistency evaluated using Cronbach α coefficient was 0.74 for IPSS and 0.15 for VPSS, respectively. Test-retest reliability testing revealed that both instruments had a high intraclass correlation index (>0.75). There was a significant correlation between the health-related quality of life (QoL) scores of the 2 instruments (0.71, P = .0001) and between the total score of each instrument with its corresponding QoL score. CONCLUSION: Although time for response of the VPSS was shorter and it demonstrated good test-retest reliability, it more frequently required help to answer. The VPSS showed low internal consistency and low correlation with the IPSS (except for the QoL item).