OBJECTIVE: Characteristics that may influence participation in DNA banks are not well defined. The purpose of this study was to examine characteristics associated with participation in a DNA bank among veterans diagnosed with Amyotrophic Lateral Sclerosis (ALS).
METHODS: Veterans who screened eligible for the National Registry of Veterans with ALS were initially contacted about the DNA Bank via telephone and then mailed a consent form. Registry participants were then categorized as consented for the DNA bank, actively refused, or passively refused (consent form not returned after >3 months and multiple reminders). The associations of consent status with age, gender, race, military branch, years of military service, VA health system use, and ALS Functional Rating Scale (ALSFRS) scores were examined.
RESULTS: Registry participants (N=1020) were 98% male, 9.5% non-white, and the mean age was 64.1 years. 61.1% of participants were current VA health system users, and the branches of service were: Army (46.1%), Navy (22.1%), Air Force (23.2%), and Marines (8.3%). A total of 14.7% of Registry participants refused DNA banking (9.4% active refusal, 5.3% passive refusal). Results from multivariable models indicated participants who were non-White, VA users, or had lower ALSFRS scores (reflecting poorer function) had higher odds of refusal. Race and VA use were associated with active refusal, while age and ALSFRS score were associated with passive refusal.
CONCLUSION: Although the overall refusal rate for DNA banking was relatively low, we still found important differences in consent by race, VA use, and functional status in this cohort of veterans with ALS. Because differential participation in DNA banking may influence generalizability, further efforts are needed to understand and intervene to reduce these differences.