Epidemiology and Treatments for Nonobstructive, Non-Neurogenic Underactive Bladder: A Systematic Literature Review

Purpose: Idiopathic underactive bladder (UAB) is a voiding dysfunction resulting in incomplete bladder emptying, usually caused by weakened bladder muscles. Owing to a lack of standardized diagnostic criteria, prevalence and treatment outcomes for this condition are not well established. Our research objectives were to document the epidemiology, treatment outcomes, and patient perspectives on the burden of idiopathic UAB. Materials and Methods: A systematic literature review was conducted. Cochrane Library, PubMed, European PubMed Central, and ClinicalTrials.gov were searched from database inception through January 8, 2025, for English-language primary source manuscripts, using terms related to idiopathic UAB, epidemiology, treatments, outcomes, and patient perspectives. Of 1293 records retrieved, 24 manuscripts were deemed eligible and included in the final review. Results and Conclusions: Idiopathic UAB was diagnosed in approximately 30% of adults undergoing urodynamic assessment for urinary symptoms, and patients with the condition reported poor quality of life (QoL). Women were underrepresented in the literature, with only 4 studies reporting prevalence and no studies reporting on QoL among female patients. While clean intermittent catheterization is the typical first-line treatment, idiopathic UAB patient experiences with catheterization were not reported. Studies of sacral neuromodulation showed low success (<50%) and high adverse event (2.5%-13%) rates. In addition, the lack of a dedicated International Classification of Diseases, 10th revision, Clinical Modification code complicated identification of this patient population in the literature. These results highlight the unmet medical needs and the opportunity for additional research and interventions focused on this common but underrecognized condition.