Systematic Review of the Cost Effectiveness of Newborn Screening for Spinal Muscular Atrophy

OBJECTIVES: Spinal muscular atrophy (SMA) is a rare condition which causes irreversible damage to motor nerves, leading to muscle wasting/weakness. New treatments for SMA have the potential to significantly improve outcomes through earlier diagnosis and treatment. This systematic review aimed to identify and appraise the literature on the cost effectiveness of newborn screening for SMA, compared to diagnosis through clinical symptoms or family history.

METHODS: A systematic literature search was undertaken from inception to 31 January 2023, using Medline, Embase, the Cochrane library and grey literature sources to identify economic evaluations of population-based screening versus no organized screening. Citations were independently reviewed by two reviewers according to pre-defined criteria. Data extraction and quality appraisal were completed in duplicate. To facilitate comparison, costs were converted to 2021 Irish Euro. The CHEC-list and ISPOR questionnaire were used to assess methodological quality and transferability of the economic evaluations, respectively. The reporting adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

RESULTS: Five studies met the inclusion criteria: four cost-utility analyses (CUA) and one cost-effectiveness analysis. Considering willingness-to-pay (WTP) thresholds of €20,000 - €45,000/quality-adjusted life year (QALY) gained, results from two CUAs suggested that screening would be cost saving, results from one CUA suggested incremental cost-effectiveness ratios (ICERs) in excess of €213,000/QALY gained, and the final CUA presented two scenarios wherein results ranged from screening being cost saving to an ICER of €307,746/QALY gained. All the models were highly sensitive to the cost of the treatment strategy, and sensitive to a lesser extent to resource use, utility values and incidence of SMA.

CONCLUSIONS: It is unclear whether screening for SMA is cost saving or results in high ICERs, as cost-effectiveness analysis results are highly dependent on the cost of the treatment strategy adopted and the associated assumptions.