LAUSR

We thank the authors for their letter on our article [1] and provide the following clarifications in response. A patientreported outcome (PRO) measure was not used as part of the methodology in this study. Indeed, PRO measure development requires a lengthy validation process, of which this was the initial phase. The findings support the development of a new PRO measure for the assessment of the signs, symptoms, and impact of underactive bladder (UAB). The study used qualitative methodology to explore the experience of UAB from a patient perspective using semistructured interviews, guided by an interview schedule. Patients were encouraged to talk in an open-ended manner about their experiences, using prompts from the interview schedule to “guide” discussion. A well-designed interview guide is important in order to help avoid possible interviewer bias or unintentional influence of the researcher on the type of responses from the subject. Exploratory qualitative interviews are particularly useful to explore around a topic for which little may be understood, as is the case with UAB. Direct patient input using qualitative research methodology is important for the demonstration of content validity when developing a new instrument [2,3]. Although the underlying aetiology of the presenting detrusor underactivity (DU) in the sample was not assessed, neurological patients were excluded. However, as UAB was the symptom complex under investigation, it was not necessary to ascertain the underlying aetiology of the DU at this stage. Indeed, there is a lack of evidence for the symptomatic presentation of its various aetiological origins, which requires further study. We took the pragmatic decision to categorise our sample by those with DU only and those with DU and coexisting conditions. This allowed the notable reporting of incontinence to be mainly associated with the inclusion of the group with those who demonstrated DU and coexisting detrusor