A cost-utility analysis of sacral anterior root stimulation (SARS) compared with medical treatment in patients with complete spinal cord injury with a neurogenic bladder.

BACKGROUND CONTEXT: Sacral anterior root stimulation (SARS) and posterior sacral rhizotomy restores the ability to urinate on demand with low residual volumes, which is a key for preventing urinary complications that account for 10% of the causes of death in patients with spinal cord injury with a neurogenic bladder. Nevertheless, comparative cost-effectiveness results on a long time horizon are lacking to adequately inform decisions of reimbursement.

PURPOSE: This study aimed to estimate the long-term cost-utility of SARS using the Finetech-Brindley device compared with medical treatment (anticholinergics+catheterization).

STUDY DESIGN/SETTINGS: The following study design is used for the paper: Markov model elaborated with a 10-year time horizon; with four irreversible states: (1) initial treatment, (2) year 1 of surgery for urinary complication, (3) year >1 of surgery for urinary complication, and (4) death; and reversible states: urinary calculi; Finetech-Brindley device failures.

PATIENT SAMPLE: The sample consisted of theoretical cohorts of patients with a complete spinal cord lesion since ≥1 year, and a neurogenic bladder.

OUTCOME MEASURES: Effectiveness was expressed as quality adjusted life years (QALYs). Costs were valued in EUR 2013 in the perspective of the French health system.

METHODS: A systematic review and meta-analyses were performed to estimate transition probabilities and QALYs. Costs were estimated from the literature, and through simulations using the 2013 French prospective payment system classification. Probabilistic analyses were conducted to handle parameter uncertainty.

RESULTS: In the base case analysis (2.5% discount rate), the cost-utility ratio was 12,710 EUR per QALY gained. At a threshold of 30,000 EUR per QALY the probability of SARS being cost-effective compared with medical treatment was 60%. If the French Healthcare System reimbursed SARS for 80 patients per year during 10 years (anticipated target population), the expected incremental net health benefit would be 174 QALYs, and the expected value of perfect information (EVPI) would be 4.735 million EUR. The highest partial EVPI is reached for utility values and costs (1.3-1.6 million EUR).

CONCLUSIONS: Our model shows that SARS using Finetech-Brindley device offers the most important benefit and should be considered cost-effective at a cost-effectiveness threshold of 30,000 EUR per QALY. Despite a high uncertainty, EVPI and partial EVPI may indicate that further research would not be profitable to inform decision-making.