MP15-14 CONVERGENT VALIDITY OF A NEW OUTCOME MEASURE FOR PATIENTS WITH UROLITHIASIS: THE WISCONSIN STONE QUALITY OF LIFE SURVEY

Abstract

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Quality of Life1 Apr 2014MP15-14 CONVERGENT VALIDITY OF A NEW OUTCOME MEASURE FOR PATIENTS WITH UROLITHIASIS: THE WISCONSIN STONE QUALITY OF LIFE SURVEY Kristina L. Penniston, Rachel Bell, and Stephen Y. Nakada Kristina L. PennistonKristina L. Penniston More articles by this author , Rachel BellRachel Bell More articles by this author , and Stephen Y. NakadaStephen Y. Nakada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.567AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The Wisconsin stone quality of life (WisQOL) questionnaire is the only disease-specific instrument for patients with kidney stones. We previously reported our development and initial validation of the instrument. We tested its convergent validity, a measure of an instrument’s correlation with a similar instrument, against the SF-36 - a widely used, generic health-related QOL survey. METHODS With institutional approval and permission to use the SF-36v2 (Optuminsight Life Sciences, Inc.), we recruited stone formers (SFs) reporting to a clinic visit for evaluation or follow-up. Patients were included if they agreed to complete both the WisQOL and the SF-36 at the visit. RESULTS Participants (n=118; M:F, 69:49; BMI, 30.0±7) were mostly middle-aged, mixed calcium SFs who had undergone prior surgical intervention (age, 53.7±16 y; prior intervention, 75%). Patients varied with respect to stone history (11.7±12 y) and for number of stone events (29% were one-time SFs, 53% had 2-10 prior events, and 18% had >10). Patients were evenly distributed for having or not having stones at the time of the survey (42% each; 24/70% reporting symptoms/no symptoms), while the remainder were unsure if they had stones. The instruments were highly correlated (R=0.56; p<0.0001). Regardless of total score, patients scoring low for items related to pain and vitality on the WisQOL also did so on the SF-36. Of the lowest-scoring patients, most scored lower on the WisQOL than the SF36. The WisQOL, but not the SF-36, captured differences between patients with and without stones at the time of the survey. While only 7 of 36 SF-32 items (19%) were different for patients with and without stones, 89% of WisQOL item scores were different based on patients' stone status. CONCLUSIONS We have previously shown that the WisQOL is sensitive in detecting differences within stone formers (discriminant validity). We now confirm, by testing the WisQOL against a validated "gold standard," that it has convergent validity. Results show excellent general correlation with the SF-36 for total QOL score and for items related to bodily pain and vitality. The SF-36 was less sensitive in detecting symptoms and differences among stone formers than the WisQOL in all other areas. Multi-center trials to continue validity testing are underway. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e150 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Kristina L. Penniston More articles by this author Rachel Bell More articles by this author Stephen Y. Nakada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...