Content validity and test-retest reliability of patient perception of intensity of urgency scale (PPIUS) for overactive bladder

Abstract

Background: The Patient Perception of Intensity of Urgency Scale (PPIUS) is a patient-reported outcome instrument intended to measure the intensity of urgency associated with each urinary or incontinence episode. The objectives of this study were to assess the content validity, test-retest reliability, and acclimation effect of the PPIUS in overactive bladder (OAB) patients. Methods. Patients undergoing treatment for OAB were recruited to participate in a non-interventional study by completing a three-day micturition diary including the PPIUS for three consecutive weeks. Following completion of the three-week study, participants from two select sites also completed a cognitive interview to assess their comprehension of the PPIUS. Results: Thirty-nine participants successfully completed the three-week test-retest study; twelve of these participants completed the cognitive interview. Test-retest reliability was high based on intra-class correlation coefficient of 0.95. Among stable patients, the difference between the mean ratings of any two weeks was non-significant. Among the twelve interview participants, nine found it simple to choose a PPIUS rating for each of their micturition episodes and most found the urgency rating definitions consistent with their urgency experiences. Conclusions: The results demonstrated content validity based on qualitative interviews, and excellent test-retest reliability among stable patients. In addition, no acclimation effect was observed among stable patients. These findings support the use of the PPIUS as a reliable measure of urgency in both clinical trial and real life settings. The validity of PPIUS could be further established with future studies investigating the relationship between discretely graded urgency and incontinence continuum. © 2012 Notte et al.; licensee BioMed Central Ltd.