Ultrasound bladder wall thickness and detrusor overactivity: a multicentre test accuracy study.
OBJECTIVE
Women with overactive bladder (OAB) often undergo urodynamics before invasive treatments are considered. Ultrasound measurement of bladder wall thickness (BWT) is a less invasive, less expensive and widely available test. It has the potential to diagnose the presence of detrusor overactivity (DO). We aimed to evaluate the accuracy of BWT in the diagnosis of DO.


METHODS
Prospective cohort study.


METHODS
Twenty-two UK clinics (university and district general hospitals).


METHODS
Consecutive eligible women with OAB symptoms had transvaginal ultrasound to estimate BWT (index test). The reference standard for the diagnosis of DO was urodynamic testing with multichannel subtracted cystometry.


METHODS
The sensitivity, specificity and likelihood ratios using a BWT threshold of ≥5 mm were used to indicate the presence of DO, and the area under the receiver operating characteristics (ROC) curve to give an overall estimate of BWT accuracy.


RESULTS
Between March 2011 and 2013, 644/687 (94%) women recruited had both tests. The mean age was 52.7 years (standard deviation 13.9) and DO was diagnosed in 399/666 (60%) women. BWT had a sensitivity of 43% [95% confidence interval (CI) 38-48%], specificity of 62% (95% CI 55-68%), and likelihood ratios of 1.11 (95% CI 0.92-1.35) and 0.93 (95% CI 0.82-1.06) for positive and negative tests, respectively. The area under the ROC curve was 0.53 (95% CI 0.48-0.57). Extensive sensitivity analyses and subgroup analyses were carried out, but did not alter the interpretation.


CONCLUSIONS
BWT is not a good replacement test for urodynamics in women with overactive bladder.


CONCLUSIONS
Bladder wall thickness is not a good replacement test for urodynamics in women with overactive bladder.
Institute of Metabolism and Systems Biology, University of Birmingham, Edgbaston, Birmingham, UK.|Birmingham Women's NHS Foundation Trust, Birmingham, UK.
P
P
Latthe
Birmingham Clinical Trials Unit, University of Birmingham, Birmingham, UK.
L
L
Middleton
Institute of Metabolism and Systems Biology, University of Birmingham, Edgbaston, Birmingham, UK.
S
S
Rachaneni
Birmingham Women's NHS Foundation Trust, Birmingham, UK.
S
S
McCooty
Birmingham Clinical Trials Unit, University of Birmingham, Birmingham, UK.
J
J
Daniels
Institute of Metabolism and Systems Biology, University of Birmingham, Edgbaston, Birmingham, UK.|Birmingham Women's NHS Foundation Trust, Birmingham, UK.
A
A
Coomarasamy
Birmingham Women's NHS Foundation Trust, Birmingham, UK.
M
M
Balogun
Medway NHS Foundation Trust, Medway Maritime Hospital, Gillingham, UK.
J
J
Duckett
Croydon Health Services NHS Trust, Croydon University Hospital, Croydon, UK.
R
R
Thakar
Health Economics Unit, University of Birmingham, Edgbaston, Birmingham, UK.
I
I
Goranitis
Health Economics Unit, University of Birmingham, Edgbaston, Birmingham, UK.
T
T
Roberts
Birmingham Clinical Trials Unit, University of Birmingham, Birmingham, UK.
J
J
Deeks
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging* / Q000473:pathology; D053201:Urinary Bladder, Overactive / Q000000981:diagnostic imaging*; D014563:Urodynamics
Bladder wall; detrusor overactivity diagnostic accuracy; overactive bladder; ultrasound; urodynamics