Introduction: The relevant terminology for stress urinary incontinence (SUI) is affected by the context, namely the clinical assessment (the symptom of SUI elicited on history taking and the sign of SUI observed during examination) or diagnostic investigations (urodynamic stress incontinence). In some cases, SUI may only be observed after the reduction in coexistent prolapse (occult SUI). Classifying SUI often relies on distinguishing between intrinsic sphincter deficiency (ISD), and urethral malposition or hypermobility, although this potentially an over-simplification.
Review: Classification systems have been derived based on clinical assessment and diagnostic testing, notably videourodynamics. Modern developments in imaging technology may allow other techniques such as ultrasound to offer additional basis for future developments in classification. Other urodynamic approaches include urethral pressure profilometry and Valsalva leak point pressure; these may offer indicators of thresholds below which ISD is more likely to explain SUI, but they are not generally accepted in routine practice.
Conclusions: While SUI classification is potentially relevant to treatment selection, evidence for influence on management outcome is limited. Generating a high-quality evidence base for treatment selection on these criteria is problematic, particularly due to the range of confounding factors. In practice, the modern practitioner relies on various tools to form an opinion on some key aspects, using the findings to derive a treatment strategy. Accordingly, there remains a need to confirm how a classification of SUI translates into treatment selection and better outcomes.