Cost Effectiveness of Newborn Screening (NBS) for Spinal Muscular Atrophy (SMA) in England

OBJECTIVES: Early diagnosis of SMA through NBS enables prompt treatment and improved clinical outcomes. Cost effectiveness of NBS followed by treatment versus a treatment pathway without NBS for SMA in England was evaluated to determine if NBS for SMA offers value for money in the health care system.

METHODS: A cost-utility analysis using a combination of decision tree and six-state Markov model structures was conducted to estimate the lifetime health effects and costs of NBS for SMA compared with no NBS from the perspective of the National Health Service (NHS) in England. The decision tree was designed to capture NBS outcomes and costs. Markov modeling was used to project long-term health outcomes and costs following diagnosis. Patients in the model entered a specific Markov model health state (walking, sitting, not sitting) after the decision tree depending on diagnosis of SMA type or SMN2 copy number. A 6‑monthly model cycle was used for the first six cycles, followed by yearly cycles to capture development/milestone changes over a lifetime. Model inputs were based on existing literature, local data, and expert opinion. Sensitivity and scenario analyses were conducted to assess the robustness of the model and validity of the results.

RESULTS: Introduction of NBS for SMA would identify approximately 59 newborns with SMA (96% of all new SMA cases in England per year). Base-case results indicated that NBS was dominant (less costly/more effective) compared with no NBS, with incremental costs of –£61,555,598 and an estimated gain of 472 quality-adjusted life-years over the lifetime of newborns identified per year. Deterministic and probabilistic sensitivity analyses demonstrated robustness of the base-case results.

CONCLUSIONS: NBS improves health outcomes for patients with SMA and is less costly compared with no NBS. Therefore, NBS is a cost-effective use of resources from the perspective of the NHS in England.