Dr. Chad Heatwole, a Cure SMA-funded researcher, and his team have published a paper in the Journal, Muscle Nerve, titled “The Spinal Muscular Atrophy Health Index (SMA-HI): A Novel Outcome for Measuring How a Patient Feels and Functions.”

This project, funded by Cure SMA, focused on developing a multi-faceted, disease-specific, patient-reported outcome to measure an SMA patient’s perception of their disease burden. The U.S. Food and Drug Administration (FDA) has emphasized the importance of the patient voice in both drug approval and drug access. The SMA-HI captures such data by allowing patients with SMA to provide direct input into their overall disease state and how they feel and function in the context of a clinical trial.

Dr. Heatwole and his team used data from a cross-sectional study of 359 international adult patients with SMA to identify the most relevant symptoms to include in the SMA-HI. They designed and validated this instrument to specifically capture disease burden of SMA patients in the context of clinical trials. The items and themes included in this instrument represent the symptomatic concepts of greatest importance to this population, as reported by patients through interviews and surveys. Fifteen adult patients and 5 patients aged 8 to 15 years participated in semi-structured qualitative interviews and found the SMA-HI to be comprehensive, easily completed, and to have clear meaning.

The SMA-HI total score demonstrated an intrinsic ability to differentiate between distinct subgroups of SMA patients with different levels of disease severity. The differences in SMA-HI total scores between various patient groups provide an important clinical reference for interpreting changes in SMA-HI scores in future clinical trials.

While the selection of SMA-HI questions focused on generating an instrument appropriate for older children, teenagers, and adults with SMA, the authors acknowledge that many of their validation steps involved participants 18 years of age or older. Despite this limitation, beta interviews with older children and teenagers with SMA suggested the relevance and usability of the SMA-HI in younger SMA patients. Additional validation studies are warranted to further demonstrate the utility, appropriateness, and performance of this instrument in the pediatric and adolescent SMA populations. Cure SMA has completed such a trial. The analysis of this research is currently underway and will provide further data regarding this instrument as a potential marker of therapeutic benefit and disease progression in younger SMA patients.

The SMA-HI has the potential to impact the SMA research community by providing researchers and clinicians with a mechanism to monitor a patient’s perception of their health in multiple symptomatic domains over time. Our thanks to Dr. Heatwole and his team for their great work in generating this important and novel outcome measure.