Improving SMA HRQOL Must Address Patient and Caregiver Well-being

The burden of spinal muscular atrophy (SMA) not only weighs heavy on patients but also extends to their caregivers, emphasize the findings of a new study, which also indicate that the well-being of patients and their caregivers are intertwined.

The data from 2 prospective studies showed correlations between impaired patient health-related quality of life (HRQOL) and disease severity, as well as correlations between the health of caregivers and their HRQOL and caregiver burden (CGB). Findings were published in Brain Sciences.

“Our findings add to the emerging research on PROM [patient-reported outcome measures] for the evaluation of novel treatment options in SMA. This study confirms that HRQOL in SMA patients is impaired with regard to physical aspects and determined by disease severity,” described the group. “Disease severity is also the main predictor of the CGB, which itself affects the caregivers’ health and HRQOL. This close and reciprocal interaction between the (physical) well-being of the patient and the well-being of the respective caregiver highlights the need not only to focus on the patients’ physical abilities but rather grasp at an overall picture of patient and caregiver health while evaluating novel treatments.”

The researchers compiled data from 2 cross-sectional and multicenter German studies, one of which included 39 patients with SMA and the other, 49 patient-caregiver pairings. All participants completed the EuroQoL 5 Dimension 5 Level Scale (EQ-5D-5L) and Short Form Health Survey 36 (SF-36). Caregivers also completed the Zarit Burden Interview (ZBI) and the Hospital Anxiety and Depression Scale.

Notably, CGB had negative correlations with the patient’s motor function, functional scores, and age. Having a higher CGB was associated with worse HRQOL, mental health impairment, and health impairments. Nearly half (46.9%) of the caregivers reported having health impairments and about 1 in 3 (32.7%) reported having mental health impairments, depression and anxiety being most prevalent manifestation, because of their caregiver role. The researchers noted that their study was unable to determine whether depression and anxiety were a result of a high CGB or if caregivers with depression and/or anxiety perceive the CGB to be higher.

Median ZBI score was 22/88, below the 24-point cut-off indicating high burden. Caregivers considered having a high burden (above the 24-point cut-off) had a duration of care of 8 hours per day; the median duration of care for caregivers in this study was 4.5 a day, which the researchers noted is lower than that found in other reports. This, they wrote, can possibly be attributed to pediatric patients—a more dependent population—being the predominant age group in those reports. In the current study, patients were at least 18 years of age.

Patients were categorized as having either high or low HRQOL (EQ-5D-5L index value < 0.259 or > 0.679), with the latter group consisting of patients with a more severe phenotype. According to the researchers, this finding was in line with previous data, which have shown an increase in HRQOL, according to EQ-5D-5L, from SMA type I to type III, accompanied by a reduction in disease severity.

“Interestingly, patients with more severe disease (SMA type II, lower motor scores), who were in the group with worse HRQOL according to the EQ-5D-5L index value, tended to have higher scores in the dimensions mental health, as well as vitality and bodily pain as previously reported for mental health and role emotional,” wrote the researchers. “SMA type III/IV patients, in contrast to SMA II, are usually older at disease onset and more frequently accustomed to a life without limitations in their daily activities, and thus find it more difficult to adapt to disease-related physical changes.”

Among patients, the lowest SF-36 scores were seen in the physical functioning dimension, followed by the role physical dimension.

Reference

Wohnrade C, Velling A, Mix L, et al. Health-related quality of life in spinal muscular atrophy patients and their caregivers—a prospective, cross-sectional, multi-center analysis. Brain Sci. Published online January 7, 2023. doi:10.3390/brainsci13010110