Validation and Reliability of the Wisconsin Stone Quality of Life Questionnaire

The Wisconsin Stone Quality of Life questionnaire (WISQOL) is a disease-specific, health-related quality of life (HRQOL) measure designed for patients who form kidney stones. The purpose of this study was to demonstrate the external and convergent validity of the WISQOL questionnaire and assess its psychometric properties.

The WISQOL creation site (development sample) and 8 geographically diverse centers in the United States and Canada (consortium sample) recruited patients with a history of kidney stones. Item response option variability, correlation patterns, and internal consistency were compared between samples. Convergent validity was assessed by patients who completed both the WISQOL and the SF-36v2.

Results from 1,609 patients (development sample, 275; consortium sample, 1,334) were analyzed. Response option variability patterns of all items were acceptable. Internal WISQOL consistency was acceptable. Inter-sample score comparisons revealed few differences. For both samples domain-total WISQOL score correlations exceeded 0.86. Item-level analyses demonstrated suitable variation allowing for discriminatory scoring. At the time they completed the WISQOL, patients with stones and stone-related symptoms scored lowest for HRQOL; patients with stones but no symptoms and those with no stones scored higher. The convergent validity sub-study confirmed ability of the WISQOL to identify stone-specific decrements in HRQOL that were not identified on the SF-36v2.

The WISQOL is internally consistent and discriminates between patients with different stone statuses and symptoms. The WISQOL is externally valid across the North American population and may be used for multi-center HRQOL studies in kidney stone disease.

The Journal of urology. 2016 Nov 23 [Epub ahead of print]

Kristina L Penniston, Jodi A Antonelli, Davis P Viprakasit, Timothy D Averch, Sri Sivalingam, Roger L Sur, Vernon M Pais, Ben H Chew, Vincent G Bird, Stephen Y Nakada

University of Wisconsin School of Medicine and Public Health, Madison, WI. Electronic address: ., University of Texas Southwestern Medical Center, Dallas, TX., University of North Carolina School of Medicine, Chapel Hill, NC., University of Pittsburgh Medical Center, Pittsburgh, PA., Glickman Urological & Kidney Institute, Cleveland Clinic, Cleveland, OH., University of California San Diego School of Medicine, San Diego, CA., Geisel School of Medicine at Dartmouth, Hanover, NH., University of British Columbia Department of Urologic Sciences, Vancouver, British Columbia., University of Florida College of Medicine, Gainesville, FL., University of Wisconsin School of Medicine and Public Health, Madison, WI.