February 05, 2010

Screening for Spinal Muscular Atrophy Not Cost-Effective: Study

FRIDAY, Feb. 5 (HealthDay News) -- It's not cost-effective to screen couples genetically to determine if they're at risk of having children with spinal muscular atrophy (SMA), says a U.S. study.

There is ongoing controversy about whether screening for SMA -- the most common genetic cause of infant death -- should be routinely offered to couples.

In this study, researchers created an analytical model to compare a policy of universal SMA screening to that of no screening. Baseline assumptions used in the model included a disease prevalence of 1 in 10,000 for a carrier rate of 1 in 50, 70 percent of affected children having severe disease.

The researchers also assumed a 90 percent sensitivity rate from carrier screening and that 2 percent of SMA cases arise from de novo mutations (genetic mutations not inherited from either parent).

The baseline cost estimates in 2009 dollars included $400 for a carrier screen and $260,000 for the lifetime cost of a child with severe disease. The researchers calculated maternal quality-adjusted-life-years assuming a 22 percent reduction in quality of life for having a child with severe SMA and 8 percent for fetal loss.

The researchers concluded that 11,000 women would have to be screened to prevent one case of SMA, at a cost of $4.7 million per case averted.

"Our findings show that screening everyone for SMA is not cost effective," study co-author Dr. Sarah Little, of Massachusetts General Hospital, said in a news release. "Our results, however, were most sensitive to changes in the baseline prevalence of disease, suggesting that prenatal SMA screening may be cost effective in high risk populations, such as those with a family history of disease."

The study was to be presented Friday at the annual meeting of the Society for Maternal-Fetal Medicine in Chicago.

More information

The Muscular Dystrophy Association has more about spinal muscular atrophy.

-- Robert Preidt
SOURCE: Society for Maternal-Fetal Medicine, news release, Feb. 5, 2010
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