SMA Impacts Health-Related Quality of Life for Both Patients and Caregivers

In addition to high health care and societal costs, spinal muscular atrophy (SMA) is associated with a deterioration in the health-related quality of life (HRQOL) of both patients and their caregivers. A new study in the International Journal of Environmental Research and Public Health estimated the economic impact and HRQOL of 86 children with SMA in 3 European countries.

The authors noted that although cost-of-illness studies are frequent for diseases with high prevalence, that is not the case with rare diseases. In the case of SMA, disability caused by the disease causes the patients to have difficulty carrying out the activities of daily living (ADL) and often creates a burden borne by families.

“Therefore, in order to quantify the real economic burden of this disease, it is therefore necessary to take a broader view, and to consider the cost of formal care and unpaid care, as well as other household costs,” they wrote.

The cross-sectional study included not only the 86 patients, but also their caregivers, in France, Germany, and the United Kingdom. The caregivers completed questionnaires about the use of public health and nonhealth resources. Data were collected between July 2015 and November 2015.

The study used the proxy version of the EuroQol 5-dimensions and 3-levels (EQ-5D-3L) for patients and EuroQol 5-dimensions and 5-levels (EQ-5D-5L) for caregivers to analyze HRQOL for both patients and caregivers. The questionnaires assess QOL across 5 domains: mobility, self-care, everyday activities, pain/discomfort, and anxiety/depression.

The researchers also used the Barthel Index to measure the ability to perform ADL and assess the degree of dependence among patients, as well as the Zarit burden interview (22-item version) to measure the burden on caregivers. In the Barthel Index, the score ranges from 0 points, meaning totally dependent, to 100 points, totally independent. The Zarit burden interview has a score range from 0 to 88—scores under 21 indicate little or no burden, while scores above 61 indicate severe burden.

There were 34 children with SMA from the United Kingdom, 27 from France, and 25 from Germany. Most were classified as having type II disease. Among the caregivers, the intensity of daily caregiving hours was higher in the United Kingdom (12.50 hours/day) compared with France (10.65 hours/day) and Germany (9.31 hours/day).

While the intensity of caregiving hours was lower in France, the burden was higher. French caregivers had a Zarit score of 40.37 compared with 26.63 among UK caregivers and 21.33 among German caregivers. French children with SMA also had a lower quality of life (0.12) compared with UK children (0.17) and German children (0.53).

The worst QOL dimension was self-care. One-third (32%) of children in Germany said they were unable to wash or dress themselves, while 41% of children in the United Kingdom and 44% of children in France said the same.

The authors noted that “neither the age of the patients nor the degree of disease progression explains the differences observed” between the HRQOL of patients in France and the United Kingdom compared with Germany.

The average annual cost associated with SMA was highest in the United Kingdom at €54,295 (approximately $64,554), followed by €51,983 (approximately $61,805) in Germany and €32,042 (approximately $38,096) in France. Direct non–health care costs ranged between 79% and 86% of the total costs among the 3 countries.

The authors concluded that there are considerable societal costs as a result of SMA in all 3 countries due to the economic impact and deterioration in the HRQOL for both patients and their caregivers.

“For this reason, when designing and evaluating any strategy or intervention for this population, the economic impact should be considered, as well as the economic evaluation of new treatments in this field,” they wrote.

Reference

Peña-Longobardo LM, Aranda-Reneo I, Oliva-Moreno J, et al. The economic impact and health-related quality of life of spinal muscular atrophy. an analysis across Europe. Int J Environ Res Public Health. 2020;17(16):e5640. doi:10.3390/ijerph17165640