title: Detrusor underactivity and the underactive bladder: a new clinical entity? A review of current terminology, definitions, epidemiology, aetiology, and diagnosis.
abstract: BACKGROUND
  Detrusor underactivity (DU) is a common cause of lower urinary tract symptoms (LUTS) in both men and women, yet is poorly understood and underresearched.
  
  
  OBJECTIVE
  To review the current terminology, definitions, and diagnostic criteria in use, along with the epidemiology and aetiology of DU, as a basis for building a consensus on the standardisation of current concepts.
  
  
  METHODS
  The Medline and Embase databases were searched for original articles and reviews in the English language pertaining to DU. Search terms included underactive bladder, detrusor underactivity, impaired detrusor contractility, acontractile detrusor, detrusor failure, detrusor areflexia, raised PVR [postvoid residual], and urinary retention. Selected studies were assessed for content relating to DU.
  
  
  RESULTS
  A wide range of terminology is applied in contemporary usage. The only term defined by the standardisation document of the International Continence Society (ICS) in 2002 was the urodynamic term detrusor underactivity along with detrusor acontractility. The ICS definition provides a framework, considering the urodynamic abnormality of contraction and how this affects voiding; however, this is necessarily limited. DU is present in 9-48% of men and 12-45% of older women undergoing urodynamic evaluation for non-neurogenic LUTS. Multiple aetiologies are implicated, affecting myogenic function and neural control mechanisms, as well as the efferent and afferent innervations. Diagnostic criteria are based on urodynamic approximations relating to bladder contractility such as maximum flow rate and detrusor pressure at maximum flow. Other estimates rely on mathematical formulas to calculate isovolumetric contractility indexes or urodynamic "stop tests." Most methods have major disadvantages or are as yet poorly validated. Contraction strength is only one aspect of bladder voiding function. The others are the speed and persistence of the contraction.
  
  
  CONCLUSIONS
  The term detrusor underactivity and its associated symptoms and signs remain surrounded by ambiguity and confusion with a lack of accepted terminology, definition, and diagnostic methods and criteria. There is a need to reach a consensus on these aspects to allow standardisation of the literature and the development of optimal management approaches.
authors.affiliation: Department of Urology, Royal Hallamshire Hospital, Sheffield, UK.
authors.forename: Nadir I
authors.initials: NI
authors.lastname: Osman
authors.affiliation: Department of Urology, Royal Hallamshire Hospital, Sheffield, UK. Electronic address: c.r.chapple@sheffield.ac.uk.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Chapple
authors.affiliation: Department of Urology, University of Bristol, Bristol, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Abrams
authors.affiliation: Department of Urology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Dmochowski
authors.affiliation: Department of Urology, Hôpital Tenon, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Haab
authors.affiliation: Department of Urology, NYU Langone Medical Center, New York, NY, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Nitti
authors.affiliation: Department of General Gynaecology and Gynaecologic Oncology, Medical University of Vienna, Vienna, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Koelbl
authors.affiliation: Department of Urology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Philip
authors.initials: P
authors.lastname: van Kerrebroeck
authors.affiliation: Division of Urology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Wein
mesh_terms: D032921:Consensus; D005260:Female; D006801:Humans; D059411:Lower Urinary Tract Symptoms / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D009626:Terminology as Topic; D001743:Urinary Bladder / Q000503:physiopathology*; D001745:Urinary Bladder Diseases / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D014563:Urodynamics
keywords: Chronic urinary retention; Detrusor failure; Detrusor underactivity; Underactive bladder