Validation of the Overactive Bladder-Bladder Assessment Tool (OAB-BAT): A Potential Alternative to the Standard Bladder Diary for Monitoring OAB Outcomes

Abstract

BackgroundAn advisory board concluded that a new, comprehensive overactive bladder (OAB) patient-reported outcome (PRO) measure should be developed in accordance with regulatory guidelines. The OAB-Bladder Assessment Tool (OAB-BAT) was developed with qualitative input from OAB patients and experts to measure symptoms, bother, impacts, and satisfaction with treatment. ObjectivePsychometric evaluation of the OAB-BAT assessing PRO OAB symptoms, bother, and impacts during a 7-d recall period. Design, setting, and participantsPsychometric testing was conducted for a 28-d observational study of 170 OAB patients. Eligibility criteria included clinician-confirmed OAB diagnosis with at least eight micturitions per day. Outcome measurements and statistical analysisAssessments included the OAB-BAT, a 7-d bladder diary, and co-validating OAB PROs. Analysis included classical and modern test theories. A scoring algorithm was developed and psychometric properties were assessed. Results and limitationsThe majority of participants were women (72.4%) with moderate OAB symptom severity (53.5%). More than one-third of participants (34.1%) were incontinent. Responses were well balanced across bother and impact items, while symptom frequency items showed sparse responses. Analysis supported an eight-item unidimensional model based on bother and impacts. No items performed differently by gender or continence status. The OAB-BAT showed internal consistency (ω=0.918), retest reliability (two-way random intraclass correlation coefficient=0.81), and convergent validity with the OAB-q (r>0.4). Known groups showed the expected trend. Comparisons between OAB-BAT scores and components of the bladder diary showed a moderate effect size (r>0.4). ConclusionsThe eight-item OAB-BAT with 7-d recall is valid and reliable as an OAB PRO measure. Structural modeling, balanced with content validity considerations, produced robust scores. The OAB-BAT is a useful addition to the clinical assessment of patients, designed to complement the use of bladder diaries for monitoring OAB outcomes, in clinical trial and clinical practice environments. Future studies will need to assess the treatment satisfaction items in a larger sample of patients receiving OAB treatment. Patient summaryWe tested a questionnaire designed to assess overactive bladder (OAB) symptoms, bother, satisfaction, and impacts by asking patients to complete it on a weekly basis. We found that the questionnaire accurately captures the symptoms and impacts that are most important to patients with OAB. We conclude that the questionnaire could be a useful instrument and, after further assessment in clinical practice and research, a possible alternative to a bladder diary in measuring OAB outcomes.