Overactive bladder phenotypes: development and preliminary data

The purpose of this study is to develop overactive bladder (OAB) phenotypes that can be used to develop diagnostic and treatment pathways and offer clues to the underlying etiologies of patients with OAB.

This is a retrospective, multicenter study of patients with lower urinary tract symptoms (LUTS). Evaluation included a 24-hour bladder diary (24HBD), the lower urinary tract symptoms score (LUTSS) questionnaire, uroflowmetry (Q), and post-void residual urine (PVR) measurement. Patients completed the 24HBD and LUTSS on a smartphone application or paper. Those with an OAB symptom sub-score (OABSS) ≥ 8 were included. An expert panel developed a phenotype classification system based on variables considered to be important for treatment.

The following variables were selected for inclusion in the phenotype modeling: 24-hour voided volume (24HV), maximum voided volume (MVV), Qmax and PVR. Subjects were divided into three phenotypes based on the 24HV: polyuria (24HV > 2.5 L), normal (24 HV 1-2.5 L), and oliguria (24HV < 1 L). Each phenotype was subdivided based on MVV, Qmax & PVR, resulting in 18 sub-types. Five hundred thirty-three patients, 348 men and 185 women, completed the LUTSS and 24HBD. OAB was present in 399 (75%) - 261 men and 138 women. The prevalence of the primary phenotypes was polyuria (25%), normal (63%), and oliguria (11%).

Classification of OAB variants into phenotypes based on 24HV, MVV, Qmax, and PVR provides the substrate for further research into the diagnosis, etiology, treatment outcomes and development of granular diagnostic and treatment algorithms.