Comparison of an adjustable anchored single-incision mini-sling, Ajust(®) , with a standard mid-urethral sling, TVT-O(TM) : a health economic evaluation

Abstract

Objectives: To assess the cost, quality of life (QoL) and cost-effectiveness of a single-incision mini-sling (SIMS; Ajust(®) , C. R. Bard Inc., New Providence, NJ, USA) compared with a standard mid-urethral sling (SMUS; TVT-O™, Ethicon Inc., Somerville, NJ, USA) in the surgical management of female stress urinary incontinence.

Patients and methods: A total of 137 women, in a secondary care setting, were randomized between October 2009 and October 2011 to undergo SIMS placement (n = 69) under local anaesthesia as an opt-out policy or SMUS placement (n = 68) under general anaesthesia. Clinical outcome measures included the patient-reported success rate (Patient Global Impression of Improvement [PGI-I]) and the impact on the patients' QoL (King's Health Questionnaire [KHQ]). Health economic data (cost and quality-adjusted life year [QALY] data) were compared using linear regression models to generate an incremental cost per QALY estimate, in order to determine a measure of cost-effectiveness. Deterministic sensitivity analyses investigated uncertainty in the results, and non-parametric bootstrapping techniques were used to estimate a probability of cost-effectiveness.

Results: There were no significant differences between the groups in terms of the KHQ total score (P = 0.27) or the patient-reported success rate (P = 1.00, odds ratio: 0.895; 95% confidence interval [CI]: 0.344 to 2.330). There was no significant difference in QALYs for the SIMS group compared with the SMUS group (mean difference: -0.003; 95% CI: -0.008 to +0.002). The SIMS was on average less costly, -£142.41 95% CI: (-316.99 to 32.17) and generated cost savings of £48 419 per QALY loss with 94% probability of cost savings to the health services. Taking a wider perspective on the costing analysis by including the wider community benefit associated with the significantly earlier return to work observed in the SIMS group (P = 0.006, 95% CI: 11.756 to 17.217), there was an increase in cost savings to -£477, (95% CI: -823.65 to -129.63), with a probability of 100% of cost savings to the wider economy.

Conclusions: The adjustable anchored SIMS (Ajust), performed under local anaesthesia as an opt-out policy, delivers cost savings to the health service provider when compared with the SMUS (TVT-O), and is likely to be cost-effective up to 1 year after placement. Further research should be undertaken to confirm the results of our study over longer follow-up and should explore patient preferences alongside an adequately powered non-inferiority randomized controlled trial.

Keywords: cost analysis; cost-effectiveness; mid-urethral slings; mini-slings; stress urinary incontinence; surgery.