Today we are publishing a suite of 4 documents relating to the review of evidence on newborn screening for spinal muscular atrophy (SMA).
You can view and download the documents by clicking on the following links:
- 2023 review of modelling studies and cost-effectiveness evaluations which address newborn screening for SMA
- 2023 evidence map to understand volume and type of published studies and evaluations of PCR-based screening and treatment of babies with presymptomatic SMA since the 2018 UK NSC review
- 2025 cost effectiveness modelling study for SMA screening in the UK context
- 2025 UK NSC review of the need for an ISE for SMA newborn screening
SMA is a rare inherited disease that can cause the nerves in the spinal cord to deteriorate. These nerves transmit instructions from the brain to the muscles that control a person’s ability to move, speak, swallow and breathe. This nerve damage causes gradual muscular weakening and muscle loss.
In 2018, the UK NSC recommended not to screen for SMA (see UK NSC recommendation) but there have been significant developments since then, including new drug treatments.
Background and early work (2022 to 2023)
A great deal of work has taken place in recent years to assess the case for newborn blood spot screening for SMA.
Following a stakeholder workshop, the Sheffield Centre for Health and Related Research (SCHARR) at the University of Sheffield was commissioned in 2022 to undertake initial scoping work. The aim of this was to understand the evidence developments in key areas and developments in work exploring the clinical and cost-effectiveness of screening.
SCHARR’s initial scoping work is presented in 2 of the documents we have published today, the:
- review of available modelling studies and cost-effectiveness evaluations which address newborn screening for SMA (accurate as of May 2023)
- evidence map to understand the volume and type of published studies and evaluations of polymerase chain reaction (PCR)-based screening and treatment of babies with presymptomatic SMA since the 2018 UK NSC review (accurate as of May 2023)
The scoping work concluded that a new, comprehensive and flexible cost-effectiveness modelling study for the UK screening context was needed to assess the uncertainties and unanswered questions of existing models.
It also concluded that systematic reviews of PCR-based screening for SMA, as well as presymptomatic treatment of SMA, should be undertaken. These have since been carried out and published by the International Journal of Neonatal Screening. See: Systematic Review of Newborn Screening Programmes for Spinal Muscular Atrophy and Systematic Review of Presymptomatic Treatment for Spinal Muscular Atrophy.
At its June 2023 meeting, the UK NSC endorsed a twofold approach to review the case for newborn screening for SMA by:
- developing a new cost effectiveness modelling study for screening for the UK screening context
- starting to plan an in-service evaluation (ISE) of screening for SMA in real world NHS services in the UK as part of the newborn blood spot screening programme
Modelling study work (2023 to 2025)
In early 2025, SCHARR completed the new modelling study, which is one of the 4 documents we have published today.
The model estimates the cost-effectiveness of newborn screening for SMA and is informed by clinical trials, relevant published literature and stakeholder workshops. The model compared the potential impact of newborn screening with the current practice of no newborn screening, and assumed that all 3 drug treatments (nusinersen, zolgensma and risdiplam) would be available.
The model estimated that newborn screening for SMA would each year:
- prevent 2 babies with SMA requiring permanent ventilation, prevent around 3 early deaths, and prevent about 30 babies being confined to a sitting state
- enable about 37 babies to live a largely normal life
However, the model also predicted that newborn screening would identify around 3 babies a year with SMA who would not be affected until adulthood, if at all, and that this information might harm their health and wellbeing.
All the analyses suggested that implementing screening could result in better outcomes and lower costs compared to the current approach of no screening plus treatment. The cost savings would depend on the treatments used and the price of treatments to the NHS.
Remaining uncertainties include:
- the approval status of 2 of the drug treatments (nusinersen and risdiplam) that the National Institute for Health and Care Excellence (NICE) is reviewing
- the actual costs of all 3 drug treatments to the NHS
- evidence of the long-term outcomes of the new treatments, including whether the estimated benefits to screen-detected babies in their first 3 years are confirmed in the real world and sustained over the longer term
SMA screening in-service evaluation
Following the cost effectiveness modelling work by SCHARR, the UK NSC conducted a review to consider whether the research questions of the ISE brief were still relevant and if an ISE was still required.
The review concluded that an ISE was still required. A brief report describing that analysis is the fourth report we have published today.
Earlier this summer, the National Institute for Health and Care Research (NIHR) advertised the research call for the SMA ISE.
The planning and development of the ISE is being overseen by a partnership board that includes:
- screening experts from the 4 UK governments and from the NHS
- stakeholder organisations interested in newborn screening for SMA
- clinicians
- academics
- genomic experts
- patient and public voice representatives
We will continue to update stakeholders and the public on the progress of this work via the blog.
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