Proxy-Reported Quality of Life and Access to Nusinersen Among Patients with Spinal Muscular Atrophy in Saudi Arabia

Background: The recent approval of innovative therapies for spinal muscular atrophy (SMA), such as nusinersen, has brought hope to patients and their families. Objective: The aims of this study were to compare the characteristics and HRQoL of SMA patients treated with nusinersen and those treated with the standard of care. Methods: This was a cross-sectional, interviewer-administered telephone questionnaire, which used a purposive sampling of SMA patients through a social support network. EuroQol five-dimensions-3-level (EQ-5D-3L) and the visual analog scale (VAS) have been used to assess the HRQoL. Different descriptive and inferential tests have been performed to compare the characteristics, EQ-5D responses, and mean scores of EQ-VAS between patients on nusinersen and the standard of care. Results: Eleven out of 36 SMA patients (30.55%) have been treated with nusinersen. Patients with type I SMA represented 54% of those treated with nusinersen (P=0.012). Only 12.5% of SMA patients living in the Mecca region are treated with nusinersen in comparison to 50% of patients living in the Riyadh region (P=0.029). No difference was noticed in the proxy-responses for the five domains of the EQ-5D or the mean VAS scores for patients on nusinersen and the standard of care despite controlling for the SMA type and the ability to breathe independently (beta= 1.39, 95% CI= - 5.15-7.93, P=0.667). However, the mean VAS score for patients who are unable to breathe independently was significantly lower than their counterparts who are able to breathe independently even after controlling for the SMA type and nusinersen treatment (beta= -31.61, 95% CI= - 51.59 - -11.63, P=0.003). Conclusion: The results of this study highlight the uncertainty about the impact of nusinersen on SMA patients' HRQoL. Therefore, the impact of nusinersen on HRQoL should be examined using more robust study designs.