Comparison of Phenotypic Characteristics and Prognosis Between Black and White Patients in a Tertiary ALS Clinic

Objective: To compare characteristics between black and white patients with ALS in order to identify disparities and phenotypic variability.

Methods: Database review occurred for patients seen between 1997-2020 at the Emory ALS Center in Atlanta, Georgia. ALS patients were included for analyses if race was self-reported as black or white and symptom onset was prior to 1/1/2017. Variables examined include race, age of onset, diagnostic delay, site of onset, median income, C9orf72 mutation status, feeding tube and tracheostomy status, vital capacity, ALSFRS-R, and survival time.

Results: 2363 patient records were queried, and 1298 were included in analysis; 203 self-identified as black and 1095 as white. Black patients had younger age of symptom onset, lower frequency of C9orf72 mutations, lower median income, longer diagnostic delay, and lower baseline ALSFRS-R and vital capacity compared to white patients. Black patients had a longer median survival than white patients; however race was not an independent predictor of survival time when controlling for age of symptom onset, bulbar onset, and C9orf72 positivity.

Conclusions: Black patients with ALS showed longer median survival compared to white patients, however race was not independently associated with survival after controlling for age, site of onset, and C9orf72 status, factors known to predict prognosis. Black patients with ALS had longer diagnostic delay and lower baseline ventilatory and functional status at first their clinic visit compared to white patients, which could be suggestive of barriers to tertiary care. Further studies are needed to identify the underlying causes of ALS racial differences.