Newborn screening for severe combined immune deficiency (SCID) saves lives and money: a cost-effective public health policy

Severe combined immune deficiency (SCID), also known as “bubble boy disease,” is a rare inherited disorder of the immune system that leads to recurrent severe infections. In the absence of effective treatment, SCID is usually fatal within the first 2 years of life. Treatment by hematopoietic cell transplantation can minimize the devastating effects of SCID, but needs to be done early in life–mortality rates are high if treatment is delayed beyond the first 3-4 months of life. Identification of infants with SCID soon after birth through public health newborn screening (NBS) allows for presymptomatic diagnosis and optimal timing of treatment of these infants. Since May 2010, SCID has been part of the US Department of Health and Human Services Recommended Uniform Screening Panel (RUSP) that state NBS programs are encouraged to follow, and most US states now screen for SCID.

Despite the condition’s rarity, affecting fewer than 1 in 50,000 infants, NBS for SCID is cost-effective because prompt treatment not only saves lives but also reduces the substantial costs associated with unnecessary hospitalizations for severe infections and transplants conducted after 3-4 months of age. At a CDC meeting that was held in late 2001 to discuss a public health approach to primary immunodeficiency diseases, I showed that a NBS test for SCID, which at the time was being developed, could be cost-effective. That hypothetical conclusion was supported by subsequent studies that projected the health and economic impacts of NBS using a T-cell receptor excision circles (TREC) molecular assay, which has high accuracy in detecting SCID in newborns using the dried blood spot specimens collected as part of NBS. Pilot studies conducted in Wisconsin and Massachusetts demonstrated the feasibility of using a TREC assay in SCID NBS and crucially contributed to the addition of SCID to the RUSP.

Washington State started screening for SCID on January 1, 2014, and the cost-effectiveness and cost-benefit of SCID NBS in Washington have been confirmed in a newly published economic evaluation by authors from the Association of Public Health Laboratories (APHL), the Washington State Department of Health, the Emory University School of Medicine, and the Centers for Disease Control and Prevention (CDC). According to their calculations, lower hospital spending for infants with SCID who are identified at birth covers much of the added cost of screening, which is estimated at roughly $8 per infant born in Washington. Screening is cost-effective, costing less than $100,000 per life-year saved under plausible assumptions.

Screening for SCID is also cost-beneficial, meaning that the economic benefit of the health improvement (i.e., saving babies’ lives) exceeds the net cost of the policy. The economic benefit was calculated by multiplying each death avoided by the “value of a statistical life” (VSL) used in regulatory impact analyses in the United States. With a VSL value of $9 million commonly used by Federal agencies, expected benefits are $5.31 per $1 in screening costs.

Public health NBS enables prompt diagnosis and treatment of rare disorders, and can save lives or prevent disability. In addition, for conditions such as SCID that require costly treatment and have highly effective interventions, early identification through NBS can save the healthcare system money as well by reducing the costs of treatment. Finally, NBS can serve as an important component of a broader public health genomics strategy for rare disorders.