Objective: To develop a valid and reliable interviewer-administered questionnaire to measure the presence and severity of storage abnormality symptoms of incontinence, urgency, frequency and nocturia.
Subjects and methods: Subjects were 930 men and women aged >/=40 years, taking part in a randomized controlled trial of a continence nurse practitioner (CNP) service. Criterion validity was tested by comparing questionnaire responses to 24-h pad test and 3-day urinary diary. Responsiveness was assessed by comparing questionnaire responses before and after treatment. Questions about urgency were investigated for construct validity in patients taking part in the trial who underwent urodynamic investigation (243). Test-retest and inter-rater reliability was measured at approximately 6 days in subjects recruited to an associated epidemiological study (104 and 102, respectively).
Results: The questionnaire responses showed significant associations with pad-test and diary measures. Questions about the severity of daytime incontinence performed better than those measuring night-time incontinence. The response categories of soaked, wet, damp and almost dry had better associations with the pad test than other measures of the severity of incontinence. Test-retest and inter-rater reliability was good for all questions, and all were responsive to change in symptoms, showing significant differences before and after treatment.
Conclusion: There is a clear need for standardization of measurement using well-validated instruments. This interviewer-administered questionnaire is valid, reliable and sensitive to change in a wide range of severity of symptoms, and in both men and women aged >/=40 years. The questionnaire provides a useful assessment tool for primary and secondary care in research and clinical settings.