Background
Overactive bladder is a common problem affecting women worldwide, with a negative effect on their social and professional lives. Before considering invasive treatments, guidelines recommend urodynamics to identify detrusor overactivity. However, the clinical-effectiveness and cost-effectiveness of urodynamics has never been robustly assessed in this cohort of women. We aimed to compare the clinical-effectiveness and cost-effectiveness of urodynamics plus comprehensive clinical assessment (CCA) versus CCA only in the management of women with refractory overactive bladder symptoms.
Methods
We did a multicentre, superiority, parallel, open-label, randomised controlled trial in 63 UK hospitals. Women aged 18 years or older with refractory overactive bladder or urgency predominant mixed urinary incontinence, with failed conservative management and being considered for invasive treatment, were randomly assigned (1:1) to urodynamics plus CCA versus CCA only. Assignment used an internet-based application with stratified random permuted blocks and site and baseline diagnosis as stratum. Primary outcome was participant-reported success at the last follow-up timepoint, measured by the Patient Global Impression of Improvement at 15 months after randomisation. Primary economic outcome was incremental cost per quality-adjusted life-year (QALY) gained modelled over the participants lifetime. Analysis was based on the intention-to-treat principle. This study is registered with ISRCTN registry (ISRCTN63268739).
Findings
Between Nov 6, 2017, and March 1, 2021, 1099 participants were randomly assigned to urodynamics plus CCA (n=550) or CCA only (n=549). At the final follow-up timepoint, participant-reported success rates of “very much improved” and “much improved” were not superior in the urodynamics plus CCA group (117 [23·6%] of 496) versus the CCA-only group (114 [22·7%] of 503; adjusted odds ratio 1·12 [95% CI 0·73–1·74]; p=0·60). Serious adverse events were low and similar between groups. Incremental cost-effectiveness ratio was £42 643 per QALY gained. The cost-effectiveness acceptability curve showed urodynamics had a 34% probability of being cost-effective at a willingness-to-pay threshold of £20 000 per QALY gained, which reduced further when extrapolated over the patient’s lifetime.
Interpretation
In women with refractory overactive bladder or urgency predominant mixed urinary incontinence, the participant-reported success in the urodynamics plus CCA group was not superior to the CCA-only group, and urodynamics was not cost-effective at the £20 000 per QALY gained threshold.
Funding
UK National Institute for Health and Care Research Health Technology Assessment Programme.
The article by Abdel Fattah et al reports on the role and the cost effectiveness of urodynamic testing in women with refractory overactive bladder (OAB) compared to standard evaluation without urodynamics. They demonstrate the non-inferiority of the standard evaluation compared to standard evaluation + urodynamic test in this group of patients. It is a robust randomised controlled trial on a large group of patients. This is extremely rare in the field of functional urology involving urodynamic assessment with a high-quality control for the traces. However, although I believe this study represents a game changing scenario in the management of women with refractory OAB, I do not believe it will mark the end of urodynamic testing in this group of patients.
An interesting finding emerges in the subgroup where the diagnosis changed following urodynamic evaluation. Based on this study, this suggests that although urodynamic examination might not be considered the standard for the overall population with refractory OAB, it might be crucial for evaluating some patient subgroups. The study reports 65 out of 487 patients (13%) changed from a diagnosis of refractory OAB or mixed urinary urge incontinence to a diagnosis of urodynamic stress incontinence. Therefore if, in this group of patients, the urodynamic examination had not been done there would probably have been an inappropriate number of treatments
Moreover, the rapidity of intervention with BoNT-A (botulinum toxin type A) injection reported in the standard evaluation group, may translate into a potentially inappropriate treatment for the long term.
The authors also give us a snapshot of the economic impact of such a test and this becomes essential in a public health context where, unfortunately, the approach to the patient cannot escape several economic considerations.
In conclusion, the FUTURE study not only demonstrates the noninferiority of standard evaluation in comparison with standard evaluation + urodynamic in the diagnostic pathway of women with refractory OAB, but looking at it from another perspective, the study suggests that urodynamic examination may play a crucial role in certain subgroups where it changes the approach and treatment. Future research should focus on better stratifying these patient subgroups to identify those for whom urodynamic examination may be crucial for guiding the correct therapeutic approach and achieving favourable outcomes.