A systematic review of measurement properties of the instruments measuring health-related quality of life in patients with irritable bowel syndrome.

PURPOSE: The systematic review of patient-reported outcome instruments can allow the selection of the most appropriate instrument for use in research and clinical practice. There has been no systematic review of the measurement properties of irritable bowel syndrome (IBS)-specific health-related quality-of-life (HRQOL) instruments. The purposes of this study were to identify all available instruments for measuring the IBS-specific HRQOL and to determine which is the most appropriate instrument to apply in clinical practice.

METHODS: A systematic review study was conducted. The MEDLINE, EMBASE, and CINAHL databases were searched. The methodological quality of the included studies was assessed using the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) checklist. The measurement property results of each study were assessed using Terwee's quality criteria.

RESULTS: Seven instruments were identified: The Irritable Bowel Syndrome-Quality of Life (IBS-QOL) instrument was the only one that had been analyzed in multiple studies, with each of the remaining six instruments only being analyzed in a single psychometric study. The IBS-QOL demonstrated moderate positive evidence for internal consistency and reliability and is the best instrument based on the currently available evidence.

CONCLUSIONS: Even though the IBS-QOL is currently the best instrument, there is conflicting evidence for its underlying structural validity. The factor structure or dimensionality of the IBS-QOL needs to be elucidated further.