Cost-utility analysis of curative and maintenance repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant unipolar depression: a randomized controlled trial protocol
Authors:   ACOUSTIM Investigators Group, Bulteau Samuel ,   HUGOPSY Network, Laurin Andrew , Volteau Christelle , Dert Cécile , Lagalice Lydie , Schirr-Bonnans Solène , Bukowski Nicolas , Guitteny Marie , Simons Luc , Cabelguen Clémence , Pichot Anne , Tessier Fabienne , Bonnin Annabelle , Lepage Adeline , Vanelle Jean-Marie , Sauvaget Anne , Riche Valery-Pierre 
Published: April 2020

Abstract
Background
Depression is a debilitating and costly disease for our society, especially in the case of treatment-resistant depression (TRD). Repetitive transcranial magnetic stimulation (rTMS) is an effective adjuvant therapy in treatment-resistant unipolar and non-psychotic depression. It can be applied according to two therapeutic strategies after an initial rTMS cure: a further rTMS cure can be performed at the first sign of relapse or recurrence, or systematic maintenance rTMS (M-rTMS) can be proposed. TMS adjuvant to treatment as usual (TAU) could improve long-term prognosis. However, no controlled study has yet compared the cost-effectiveness of these two additional rTMS therapeutic strategies versus TAU alone.

Methods/design
This paper focuses on the design of a health-economic, prospective, randomized, double-blind, multicenter study with three parallel arms carried out in France. This study assesses the cost-effectiveness of the adjunctive and maintenance low frequency rTMS on the right dorsolateral prefrontal cortex versus TAU alone. A total of 318 patients suffering from a current TRD will be enrolled. The primary endpoint is to investigate the incremental cost-effectiveness ratio (ICER) (ratio costs / quality-adjusted life-years [QALY] measured by the Euroqol Five Dimension Questionnaire) over 12 months in a population of patients assigned to one of three arms: systematic M-rTMS for responders (arm A); additional new rTMS cure in case of mood deterioration among responders (arm B); and a placebo arm (arm C) in which responders are allocated in two subgroups: sham systematic M-rTMS and supplementary rTMS course in case of mood deterioration. ICER and QALYs will be compared between arm A or B versus arm C. The secondary endpoints in each three arms will be: ICER at 24 months; the cost-utility ratio analysis at 12 and 24 months; 5-year budget impact analysis; and prognosis factors of rTMS. The following criteria will be compared between arm A or B and arm C: rates of responders; remission and disease-free survival; clinical evolution; tolerance; observance; treatment modifications; hospitalization; suicide attempts; work stoppage; marital / professional statues; and quality of life at 12 and 24 months.

Discussion
The purpose of our study is to check the cost-effectiveness of rTMS and we will discuss its economic impact over time. In the case of significant decrease in the depression costs and expenditures associated with a good long-term prognosis (sustained response and remission) and tolerance, rTMS could be considered as an efficient treatment within the armamentarium for resistant unipolar depression.

Trial registration
ClinicalTrials.gov, NCT03701724. Registered on 10 October 2018. Protocol Amendment Version 2.0 accepted on 29 June 2019.