SMA Carries Substantial Cost and Healthcare Burden, Review Finds
A “significant” economic burden is associated with spinal muscular atrophy (SMA), although differences in healthcare costs and resource use are evident among patients by SMA type, a large review study found.
Not surprisingly, the greater burden is among patients with SMA type 1, one of this disease’s most severe forms with onset in infancy.
The study, “Systematic Literature Review to Assess the Cost and Resource Use Associated with Spinal Muscular Atrophy Management,” was published in PharmacoEconomics.
SMA, a neuromuscular disease, is characterized by a deletion or mutation in the SMN1 (survival of the motor neuron 1) gene that provides the instructions to produce survival motor neuron (SMN) protein. The SMN2 gene helps to allay the degree of deficiency, but SMN2 only produces about 10–15% of functional SMN protein.
Motor neurons, those that control movement, are sensitive to low SMN protein levels, leading to progressive loss of muscle control.
SMA is classified into five types, 0 to 4, based on patient’s age at disease onset and the highest motor milestones achieved.
Regardless of disease severity and access to treatment, a multidisciplinary approach is need in care. Global data is limited regarding the cost and resource use associated with managing SMA, the review study noted.
Researchers at Roche, added by those with a marketing access solutions company in the U.K., looked at 51 reports and studies focusing on the cost and healthcare resource utilization of SMA in 14 countries: the U.S., the U.K., Italy, Australia, Canada, Germany, Croatia, Korea, Japan, France, Spain, Sweden, Russia, and Turkey.
Many of the studies were grouped by SMA type, with the review conducted in August 2019 and updated in July 2021. Costs given were converted to 2019 euro values for consistency across countries, currencies, and methods of reporting used.
Parameters analyzed included medical costs associated with inpatient and outpatient hospitalizations, consultations with specialists and other healthcare providers, current treatment use, tests and other examinations, and rehabilitation.
Most medical costs and resource use reported were highest for those with type 1 SMA, decreasing incrementally for patients with types 2 and 3, the analysis showed.
A study from Germany into resource use, published in 2016, found inpatient hospitalizations required by 67% of type 1 patients compared with 17% of type 2s and 7% of types 3s; outpatient medical consultations were needed by 100% of type 1 patients and 79% and 54% of those with types 2 and 3, respectively.
Rehabilitation resources were used by 100% of type 1 patients and 96% of type 2 and 79% of type 3 patients.
Use of sleep studies, available pharmaceutical treatments, medical aids, and respiratory management were most common in patients with type 2 SMA, while the highest need for psychological assistance was seen in type 3 patients in the German study.
An Italian National Health Service study of annual direct medical costs incurred per patient by disease type, published in 2019, also found costs higher for those with type 1 SMA compared with types 2 or 3.
In Spain, an analysis of hospital admission records across 18 years (1997–2015) showed that the average yearly cost of admission was associated with length of hospital stay and SMA type. A U.S. records study (2006–16) found average total healthcare costs, relative to an age-matched control group, to be 54.2 times higher among those with infantile-onset disease, and 33.7 and 3.1 times higher among childhood-onset and later-onset patients, respectively.
A 2018 study reported a higher lifetime medical cost to be associated with types 2 and 3, compared with type 1. However, the review’s researchers noted that this finding could change with the availability of disease-modifying therapies for SMA.
Where the cost categories were similar in studies, direct costs — those associated with treatments and medical needs — were much lower in Europe than in the U.S., the review found.
For example, the mean annual inpatient cost per SMA patient was €24,193 (about $27,362 today) in a 2016 German study, and €3,490.52 in a study from Spain published in 2020. In contrast, a U.S. study based on 2012 data found the monthly inpatient costs for infants with SMA to be €22,500 — amounting to €270,000 over one year.
Early data on how disease-modifying treatments might impact costs and resource use found “no effects” for types 2 and 3 in the review. A U.S. study published in 2020, however, reported fewer hospital inpatient days per person per year for type 1 patients being treated with Spinraza (nusinersen) relative to those not on the approved therapy — 4.6 versus 14.1 days, respectively. And a 2019 published study found a drop in costs associated with managing SMA three months after patients started on Spinraza.
Two 2019 abstracts from the U.S. suggested that Zolgensma (onasemnogene abeparvovec), an approved gene therapy, could lead to lower direct medical costs for type 1 patients compared with Spinraza treatment.
“Current research demonstrates that disease-modifying therapies can potentially reduce spinal muscular atrophy costs, but more information is needed across all spinal muscular atrophy types,” the researchers wrote.
Disease-modifying “treatment costs will need to be considered in future assessments,” they added.
Nonmedical costs associated with SMA include travel, adaptations to the home, and assistive devices. Studies that reported on these costs highlighted a significant travel burden for patients and their caregivers, including flight costs to attend treatment centers and housing accommodations near those centers. An SMA UK survey of 188 patients (types 1-3), published in 2019, reported that mean annual out-of-pocket costs associated with health materials, travel, and accommodations was €8,329.68 per patient, with a 2020 study from Australia finding SMA type 2 is associated with the highest per patient travel costs (€2,386.91).
Six studies looked at costs tied to home and vehicle modifications, with the 2012 U.S. study finding mean annual per patient cost for home modifications or moves to be €3,023.19 for those with early-onset SMA and €2,780.26 for those with later-onset SMA.
Indirect costs, or those associated with lost income, lost productivity, and time spent in giving care, were highest across a number of studies for caregivers of type 1 patients, who generally require the most care.
“Indirect costs were primarily associated with informal care, which was a substantial burden on patients and families in terms of both cost and time,” the researchers wrote.
Informal caregivers, or family members providing unpaid care, spend an average of 12.50 hours each day caring for SMA patients in the U.K., 10.65 hours per day in France, and 9.31 hours daily in Germany, the review found. These caregivers also had a 3.63-point higher likelihood of spending more than 10 hours a day providing care if the patient had type 1 SMA compared with type 3.
Major drivers of costs in managing SMA, the review reported, were the need for inpatient care, use of outpatient services or specialist visits, respiratory care, rehabilitation, orthopedic care, prescription costs (excluding disease-modifying therapies), home stays, and modifications to the home or car. One 2018 study in Italy found type 1 costs driven by respiratory care, and costs for types 2 and 3 driven by orthopedic care.
Overall, “cost drivers were generally found to be dependent on SMA type,” the researchers wrote.
Based on these findings, the researchers concluded that SMA “causes a significant burden to patients, caregivers and healthcare systems, although the extent of the burden is dependent on the type of spinal muscular atrophy reported.”
They noted that further “long-term robust studies are required to fully elucidate the economic burden of SMA,” adding “it would be beneficial to understand how cost and resource use are affected by different degrees of ambulation, or generally by different motor function levels.”
Determining those factors with the most impact on the quality of life of SMA patients is also important, the team wrote.