Cost-effectiveness analysis of sacral neuromodulation (SNM) with Interstim for fecal incontinence patients in Spain

Introduction: Fecal incontinence (FI) is a condition with a high impact on the psychological and social life of healthy people. Interstim, the sacral neuromodulation (SNM) therapy, has shown higher effectiveness and safety rates than surgical procedures like dynamic graciloplasty or artificial anal sphincter in patients with intact anal sphincter (IAS) and after sphincteroplasty in patients with structurally deficient anal sphincter (SDAS). Objective: To assess the cost-effectiveness of A management in two scenarios - with and without SNM - and to estimate the potential budget impact of its progressive introduction in the Spanish setting. Methods: Two decision analytical models were developed (IAS and SDAS patients) representing the possible clinical paths for each of the scenarios (with and without SNM), as well as its clinical and economic consequences in the mid-to long term with a Markov model. Clinical and resource use data were retrieved from the literature and validated by a clinician expert panel. Effectiveness was measured with both QALYs and symptom-free years (SFY). A 3% discount rate was used for future costs and benefits (time horizon = 5 years). Prevalence figures were combined with Interstim sales forecasts to estimate the total number of patients to receive therapy over the next 5 years and the associated budget impact. Results:The introduction of Interstim in the therapeutic management of FI has an associated cost-effectiveness of El 6 181 (IAS patients) and (22 195 (SDAS patients) per QALY gained. The progressive introduction of Interstim in 75 to 100 patients/year will have an estimated budget impact of 0.1 % of incremental costs in patients with Fl. Conclusions: Introducing Interstim in the management of A in AS and SDAS patients in the Spanish setting has shown to be an efficient measure with an incremental cost-effectiveness ratio below the accepted Spanish threshold (around (sic)35 000/QUALY), and with a relatively low additional cost for the Spanish NHS.