Assessing Cost and QOL in Patients With SMA Before Symptoms Appear

Although treatments for spinal muscular atrophy (SMA) are expensive, patients with SMA who were identified and treated earlier had lower total financial costs and improved quality of life (QOL) than patients who started treatment after the onset of symptoms. The study, published in Developmental Medicine & Child Neurology, suggests a positive impact of newborn screening (NBS), according to the authors.

SMA occurs in approximately 1 in 10,000 live births and is a progressive muscle weakness. In the most common and severe form, SMA causes death or permanent ventilation in 94% of patients under the age of 2. The other 2 forms of SMA are associated with severe motor disability but a longer life expectancy that is almost on par with the general population.

Some patients may be identified before the onset of symptoms because of NBS or a sibling diagnosed with SMA, the authors explained. There are 3 approved drugs for SMA. “Despite the substantial burden and cost of SMA, these drugs are very expensive relative to the benefit that they bring to patients who are not treated until after they develop symptoms,” they wrote.

In this study, the authors assessed and compared QOL and societal costs of untreated patients, treated patients identified by the onset of symptoms, and treated patients prior to symptoms who are identified through testing. The researchers collected questionnaires completed by the patients or parents, as well as medical and financial records from hospitals.

There were 149 patients enrolled. Of the total study population, 93 patients were untreated symptomatic patients between the ages of 2 and 59 years; 81 patients had been followed up from a study conducted in Belgium, France, and Germany between 2016 and 2018 (NatHis-SMA); and 12 patients had been followed up from a study conducted in Liege, Belgium, among neuromuscular reference centers (Liege NMRC).

Overall, the costs for treated patients were significantly higher compared with untreated patients due to the high cost of the SMA therapies. Among the treated patients, those not identified by symptoms had lower total costs compared with the treated symptomatic patients.

“When treatment costs were not considered, the direct costs for patients not identified by symptoms were statistically much lower than those for untreated and treated symptomatic patients,” the authors noted. Removing treatment costs, the direct costs for untreated and treated symptomatic patients were similar.

Costs of untreated patients in southern Belgium were similar to costs reported in analyses from France, Germany, Spain, and the United Kingdom, the authors noted. Costs for patients in the United States and Australia were significantly higher, especially for patients with the most severe form of the disease.

QOL scores were measured using Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales and the PedsQL neuromuscular module (NMM). Scores were higher among patients not identified by symptoms compared with the other groups, “but the sample size was too small to conduct a formal comparison.”

Health-related QOL was measured with the Health Utilities Index (HUI). Scores were, again, much higher for patients not identified by symptoms, and according to the HUI scale, some of these patients reached full health. The patients not identified by symptoms had better motor development than treated symptomatic patients.

Overall, the authors concluded that when treatment is available, identifying patients earlier results in short-term savings. They added that more follow-up is needed to confirm the long-term cost-effectiveness of NBS.

“These data are important as they are issued from a real-life prospective collection,” senior author Laurent Servais, PhD, of the University of Liege, in Belgium and the University of Oxford, in the United Kingdom, said in a statement. “They demonstrate clearly that as long as the decision to reimburse treatments for SMA has been made, newborn screening becomes a no-brainer—not only because it gives patients a much better future, but also because it saves a significant amount of money for the taxpayer. Using these data issued from the real world, we are working currently on a model that estimates the lifetime cost of the different strategies.”

Reference

Dangoulolff T, Hiligsmann M, Deconinck N, et al. Financial cost and quality of life of patients with spinal muscular atrophy identified by symptoms or newborn screening. Dev Med Child Neurol. Published online June 8, 2022. doi:10.1111/dmcn.15286