The validity and responsiveness of the ICECAP-A capability-well-being measure in women with irritative lower urinary tract symptoms

Abstract

PURPOSE: A desire to incorporate broader aspects of well-being in health economic evaluations has led to the development of the ICEpop CAPability measure for Adults (ICECAP-A). The ICECAP-A draws upon Amartya Sen's capability approach and conceptualises well-being as the capability to achieve Stability, Attachment, Autonomy, Achievement, and Enjoyment. The aim of this study was to assess the psychometric performance of the ICECAP-A in a context where patient outcomes can extend beyond health-related quality of life. METHODS: Longitudinal data were collected for 478 women with symptoms of urinary frequency and urgency, with or without incontinence. Women were recruited across 22 hospitals in the UK and had a mean age of 55 (SD 14). The psychometric performance of the measure was evaluated in relation to the EuroQol Five-Dimension Questionnaire (EQ-5D-3L) and the International Consultation on Incontinence Questionnaire for Overactive Bladder (ICIQ-OAB) and involved an assessment of acceptability, construct validity, and responsiveness using parametric and nonparametric methods. RESULTS: ICECAP-A showed good convergence with the ICIQ-OAB with 20 out of 22 expected patterns of relationship confirmed. Findings suggested that the ICECAP-A has better discriminative properties than EQ-5D-3L and as good as those of the ICIQ-OAB, confirming expected associations with clinical and demographic factors. The ICECAP-A was more responsive than EQ-5D-3L and ICIQ-OAB to deteriorations of clinical symptoms. Improvements in symptoms were not valued as highly as deteriorations by either ICECAP-A or EQ-5D-3L. CONCLUSIONS: The ICECAP-A is a valid and responsive measure capturing broad emotional and practical impacts of urinary symptoms on women's well-being and could be considered for use in economic evaluations in this context.