No superiority for onabotulinumtoxinA vs sling for urinary incontinence

No superiority for onabotulinumtoxinA vs sling for urinary incontinence | Image Credit: © ibreakstock - © ibreakstock - stock.adobe.com.

Outcomes among women with urinary incontinence do not differ based on using onabotulinumtoxinA or a midurethral sling, according to a recent study published in JAMA Network Open.¹

Prevalence and impact of mixed urinary incontinence

The prevalence of mixed urinary incontinence (MUI) increases with age, estimated in 30% of US women aged at least 60 years. This condition can lead to multiple adverse emotional, physical, economic, and social effects.²

Treatment often begins with the urge urinary incontinence (UUI) component with onabotulinumtoxinA or sacral neuromodulation.¹ However, this does not always improve the stress urinary incontinence (SUI) component.

“Similarly, until recently, there have been limited data on whether treating the SUI component with a midurethral sling would substantially improve the UUI component,” wrote investigators.

Comparing treatment methods

The study was conducted to determine which treatment is superior for improving MUI symptoms. Participants included women aged 21 years or older with at least 3 months of moderate or severe SUI and UUI symptoms, a positive cough stress test, at least 4 documented UUI episodes, and unsuccessful conservative treatments.

Treatment included onabotulinumtoxinA, 100 U provided through an intradetrusor injection or synthetic polypropylene mesh midurethral sling, with participants randomized to receive either method. In the onabotulinumtoxinA group, patients could undergo additional injections from 3 to 6 months.

Urinary incontinence outcomes

The change in MUI symptoms at 6 months was reported as the primary outcome, measured using the Urogenital Distress Inventory (UDI) with a score from 0 to 300. Subscales of the UDI, ranging from 0 to 10,0 include irritative symptoms, stress incontinence, and obstructive symptoms. Higher scores indicate increased symptom severity.

UDI total scores at 3 months the UDI stress and irritative subscale scores at 6 months were reported as secondary outcomes. The change in UDI total, stress, and irritative scores at 12 months was also reported. The Incontinence Impact Questionnaire was used to measure incontinence-specific quality of life.

Study population and outcomes

There were 130 patients with 12-month follow-up data included in the final analysis, 67 of whom were in the onabotulinumtoxinA group and 63 were in the sling group. Participants were aged a mean of 59 years, with a mean MUI severity based on UDI total score of 184.3. A mean of 7.2 incontinence episodes were reported per day.

No significant differences in improvements for 6-month UDI total scores were reported between groups, at -66.8 points among onabotulinumtoxinA recipients and -84.9 among sling recipients. This indicated a mean difference of 18.1 points, highlighting no superiority from either treatment method.

Similarly, UDI total scores at 3 months did not significantly differ between groups, with a mean difference of 4.7 points. The decrease in the UDI irritative score was significantly reduced among the onabotulinumtoxinA group compared to the sling group, but this difference was not present at 6 months.

At 6 months, a difference in UDI stress score improvement was reported, at -45.2 in the sling group vs -25.1 in the onabotulinumtoxinA group, for a mean difference of -25.1. The UDI total score also widened between groups at 12 months, with a difference of 24.4. However, this remained below the minimal clinically important difference of 26.1.

Quality of life and overall improvement

Incontinence-specific symptoms, quality of life, and satisfaction improved in both groups, with most participants having satisfactory improvement at 6 and 12 months. Additionally, a reduction in daily incontinence episodes was reported in both groups, at -2.9 in the onabotulinumtoxinA group and -4 in the sling group.

These results indicated no significant symptom improvement at 6 months from onabotulinumtoxinA injection vs midurethral sling surgery among patients with MUI. As one therapy may not be adequate for symptom treatment, 22.6% of patients received both therapies by 12 months.

“These findings may help inform treatment decisions based on patient preference in partnership with clinician recommendations,” concluded investigators.

References:

1. Harvie HS, Menefee SA, Richter HE, et al. Midurethral sling vs onabotulinumtoxinA in females with urinary incontinence: the MUSA randomized clinical trial. JAMA. 2025. doi:10.1001/jama.2025.4682
2. Frick AC, Huang AJ, Van den Eeden SK, et al. Mixed urinary incontinence: greater impact on quality of life. J Urol. 2009;182(2):596-600. doi:10.1016/j.juro.2009.04.005