Bladder ultrasonography for diagnosing detrusor overactivity: test accuracy study and economic evaluation

Area of Science:

• Urology
• Diagnostic Imaging
• Health Technology Assessment

Background:

• Urodynamics (UDS) is the gold standard for diagnosing detrusor overactivity (DO) in women with overactive bladder (OAB).
• Bladder ultrasonography (measuring bladder wall thickness, BWT) is a less invasive proposed alternative for DO diagnosis.

Purpose of the Study:

• To evaluate the reliability, reproducibility, accuracy, and acceptability of BWT measurement for diagnosing DO in women with OAB.
• To explore the role of UDS in treatment outcomes and conduct an economic evaluation of care pathways.

Main Methods:

• A cross-sectional test accuracy study involving 687 women with OAB across 22 UK hospitals.
• BWT measured via transvaginal ultrasonography; DO assessed via UDS (blinded).
• Reproducibility, sensitivity, specificity, pain, acceptability, symptom scores (ICIQ-OAB), and cost-effectiveness were analyzed.

Main Results:

• BWT demonstrated very low sensitivity and specificity for DO diagnosis, with no significant discriminatory power.
• Ultrasonography was more acceptable to patients but less reliable and reproducible than UDS.
• Urodynamic diagnosis strongly correlated with subsequent treatment; BWT showed no relationship with symptom improvement.

Conclusions:

• Bladder ultrasonography for BWT measurement lacks diagnostic and prognostic value for DO in women with OAB.
• Despite higher patient acceptability, BWT measurement is not sufficiently reliable or reproducible for clinical use.
• Urodynamics remains the most cost-effective strategy for diagnosing DO and guiding treatment in OAB patients.