SIMS - PILOT: Single Incision Mini-Slings versus standard midurethral slings in surgical management of female stress urinary incontinence

Stress urinary incontinence (SUI) is the most common type of urinary incontinence (UI) in pre-menopausal women, accounting for almost 50% of cases. Surgical procedures for the management of female SUI have been continuously evolving over the last four decades with the ultimate aim of providing an effective and truly ambulatory surgical procedure. However, evidence on the clinical and cost-effectiveness of new methods of surgery is lacking.

The aim of this study was to conduct an initial health economic evaluation alongside a pilot randomised controlled trial comparing single incision mini-slings (SIMS), performed under local anaesthetic with standard midurethral slings (SMUS) performed under general anaesthetic for the surgical treatment of SUI. The study assessed the costs to the NHS, quality of life implications (generic and condition specific QoL) and cost-effectiveness outcomes. Trial follow-up was one-year duration.

The results of our study generated the only available information in relation to the cost-effectiveness of these interventions and made an important contribution to the literature evaluating surgical methods for urinary incontinence. There were no significant differences between randomised groups in terms of QoL or patient-reported success rate. However the SIMS intervention has the potential to generate cost savings to the NHS and was on average £142 less costly compared to SMUS, generating incremental cost savings of £48,419 per QALY lost in the base case analysis, with a 94% probability of cost-effectiveness. Results were driven by the savings accrued from performing the SIMS procedure under local anaesthetic. Including a wider perspective and the potential for earlier return to work further increased the potential for SIMS to be a cost-effective procedure for SUI.

Outcome and Translation

The results of this work contributed to a successful funding application for a currently on-going large, UK-wide RCT: ‘Single-incision Adjustable Mini-Slings versus standard tension-free mid-urethral slings in the management of female stress urinary incontinence; a pragmatic multicentre non-inferiority randomised controlled trial: The SIMS Trial'

Additionally, a 4 year follow up of the SIMS Pilot study is underway.

HERU researchers involved in this research project: Dwayne Boyers and Mary Kilonzo


Boyers, D., Kilonzo, M., Mostafa, A. and Abdel-Fattah, M. (2013) 'Comparison of an adjustable anchored single-incision mini-sling, Ajust®, with a standard mid-urethral sling, TVT-OTM: a health economic evaluation', BJU International, 112(8), 1169-1177.


Boyers, D., Kilonzo, M., Mostafa, A. and Abdel-Fattah, M. (2012) 'Single Incision Mini Slings versus standard mid urethral slings, a cost-effectiveness analysis alongside a randomised controlled trial', International Continence Society, Beijing, China, September 2012.