Underactive bladder (UAB) is commonly encountered but poorly defined. Though detrusor underactivity is the accepted underlying mechanism of UAB, a distinct clinical syndrome has not been described. As such, there is a delay in identifying affected individuals and effective treatments are limited. Validated self-reported symptom measures are invaluable tools for uniform and reproducible symptom assessment and are needed to better characterize this condition, efficiently identify patients, and enable innovation in treatment modalities. We describe the development and validation of a self- reported measure for UAB.

Following federal guidelines for Patient Reported Outcome Measures (PROM) development and validation, we implemented a 5-stage study design, including sequential qualitative and quantitative assessments.

Using existing UAB literature and clinician expert opinion we developed a conceptual model for the study, consisting of five domains including symptoms (e.g. storage, voiding, post-voiding) and impacts (e.g. activities of daily life, burden, quality of life). Phase I focused on concept elicitation and symptom identification through the use of qualitative focus groups and phone interviews. Data collected during the focus groups informed the development of the concept elicitation interview guide. Patients with urodynamic detrusor underactivity were identified and concept elicitation interviews were performed to identify condition specific symptoms, determine the language used by individuals to describe their symptoms and to assess symptom prevalence. Using this data, we created a draft self-administered multidimensional risk assessment questionnaire, containing 34 questions. A separate sample of patients with and without detrusor underactivity were utilized to perform cognitive debriefing of the instrument to assess comprehension, face validity and content validity. A revised questionnaire was created and subjected to psychometric validation with a 3rd cohort of both urological patients and healthy controls. A quantitative scoring algorithm was also developed.

The final instrument is a 14 item self-reported measure focused on symptoms and quality of life, designed to be consistent with Lower Urinary Tract Dysfunction Research Network Comprehensive Assessment of Self Reported Urinary Symptoms. It is designed to be completed in 5-10 minutes. Most questions are on a 5 point rating scale with a recall period of one week.

This patient reported measure is an important first step in filling knowledge and treatment gaps surrounding underactive bladder. It will allow for the early identification of affected individuals, facilitate further study of this population,  open for door for development of novel therapies for underactive bladder, and it may also help to predict treatment outcomes for currently available therapies for lower urinary tract symptoms.

Continence 7S1 (2023) 100874
DOI: 10.1016/j.cont.2023.100874