Development and validation of the Italian version of the intermittent self-catheterization questionnaire

BACKGROUND: Intermittent self catheterization questionnaire (ISC-Q) is a questionnaire exploring four issues related to self-intermittent catheterization (ISC): ease of use, convenience, discreteness and psychological well-being. The aim of the study was to develop and validate the Italian version of the ISC-Q. METHODS: Two independent translations of the ISC-Q were performed and compared by an expert committee. A back translation to English was made by a linguistic expert, blinded to the original version. Patients using ISC to void their bladder were from 19 different spinal cord units; questionnaires were examined anonymously in a single center. A subgroup of 47 patients repeated the test at 2 weeks distance and completed the Qualiveen questionnaire to assess the convergent validity of ISC-Q. The internal consistency was determined from Cronbach's α coefficient. Criterion validity was determined through the concurrent use of Qualiveen. Reliability was performed by Intraclass Correlation Coefficient and test-retest. The sensitivity was determined by the effect size-based estimate for small change (ES) and Minimal Detectable Change 95 (MDC95). In the study 217 subjects (65.6% males, 34.4% females) were enrolled. Mean age: 43±10.1 years. Mean duration of ISC: 3.3±6.9 years. RESULTS: Cronbach's α ranged from 0.79 to 0.81. Pearson correlation between the different parts of ISC-Q and total score ranged from 0.24 to 0.78. ICC values were higher than 0.9. Convergent validity was faint to null. ES ranged from 3.8 to 6 points. MDC95 ranged from 4.1 to 12.1. CONCLUSIONS: The Italian ISC-Q has the same psychometric characteristics of the original questionnaire. ISC-Q is a valid, reliable and sensitive patient related outcome, specifically focused on ISC. our work provides a new validated measure for Italian patients to explore in future studies the role and impact of ISC.