Costs of SMA ‘Extremely High’ Prior to Disease-modifying Treatments
Hong Kong study looks at needed care and deaths for patients born 2000-2018
Without disease-modifying treatment (DMT), spinal muscular atrophy (SMA) carries high mortality rates and steep healthcare costs, a study in Hong Kong reported.
Not surprisingly, the greatest loss of life and highest costs were observed in children with SMA type 1, one of this disease’s most severe forms with onset in infancy.
These findings underscore the importance of an early start to treatment and newborn screening (NBS) programs to test infants for the disease.
“The available disease-modifying treatments need to be given in a timely fashion to alter the disease course and prevent the development of severe disease and disability. This is beneficial not only to patients but also to the healthcare systems,” the researchers wrote.
Mean per-patient costs with SMA type 1 reaching almost $1 million
The study, “Significant healthcare burden and life cost of spinal muscular atrophy: real-world data,” was published in The European Journal of Health Economics.
The first DMTs for SMA became widely available in the late 2010s. While these medications have had dramatic effects on SMA outcomes, they also come with high price tags.
“Real-world data on the economic burden and healthcare costs of SMA prior to the availability of these disease-modifying treatments (DMTs) are, therefore, very important when considering the impact of no DMTs on the medical care costs,” the researchers wrote.
“Currently, long-term mortality and economic data of SMA are still limited, and modeling analyses are frequently used for estimations,” they added.
A research team at the University of Hong Kong retrospectively analyzed the mortality rate and cumulative direct medical costs of 71 children born with SMA in Hong Kong from 2000 through 2018, when Spinraza (nusinersen), the disease’s first DMT, became available there.
Among the children, 34 had SMA type 1, 27 had the intermediate type 2, and 10 had milder type 3 disease. They were followed up from birth until they died, left Hong Kong, reached 18 years, or initiated DMT.
Direct medical costs included “attendances of special outpatient clinics, emergency department, allied health services, and mean length of stay in hospitals over time,” the researchers wrote, adding that total costs “were calculated as unit costs multiplied by utilization frequencies of corresponding healthcare services at each age.”
Over a median follow-up of six years, 36.6% of the patients died.
Deaths were recorded for 67.7% of the children with SMA type 1 (at a median age of 0.8 years) and 11% of those with type 2 (at a median age of 10.9 years). This translated to a 92.2% lower risk of all-cause death for type 2 children relative to those with type 1. No child with type 3 disease died during follow up.
In the overall patient group, the mean cumulative per-patient healthcare cost (in U.S. dollars) from birth to age 18 was $935,570. The highest cumulative per-patient cost was reported for type 1 patients, at $2.39 million; these costs were $413,165 for type 2 and $40,735 for type 3.
“The results of our analysis show that the healthcare costs of SMA-related direct inpatient and outpatient costs are extremely high,” the researchers wrote.
Total healthcare costs rose with age more rapidly for children with SMA type 1 than for those with types 2 or 3.
Hospitalizations were biggest drivers of costs. The highest healthcare costs were generally incurred in the first few years of life, with annual costs tending to decrease later in childhood and in adolescence.
The team noted that these numbers are likely an underestimation of total health-related costs for an SMA patient, as some cost data were not available, and the models did not account for rehabilitation equipment, special education needs, and other indirect costs.
In addition, given SMA’s multi-system and progressive nature, all children with SMA type 1 or 2, and some with type 3 at later disease stages “required frequent admissions and consultations by multiple subspecialties and allied health professionals,” the researchers wrote.
These findings provide “accurate real-world evidence of the extremely high healthcare costs from the significant healthcare service utilization among pediatric SMA patients before the availability of these disease-modifying treatments,” especially for those with type 1 disease, the team wrote.
The results also “provide compelling and cost-effective evidence” in support of newborn screening programs that aim to facilitate early diagnosis by testing all newborns for the disease.
“Through NBS and early disease-modifying treatments, the extremely high SMA-associated healthcare costs can be effectively minimized, and the significant disability and high mortality of the disease can also be prevented,” the researchers concluded.