Impact of the COVID‐19 pandemic on enrollment at United States Alzheimer’s Disease Research Centers

Abstract

AbstractBackgroundImpacts of the COVID‐19 pandemic have been disproportionate by race/ethnicity and sex. We aimed to characterize the impact of the pandemic on enrollment in US Alzheimer’s Disease Research Centers (ADRCs) overall and by race/ethnicity and sex using National Alzheimer’s Coordinating Center (NACC) data.MethodsWe included data on N = 8875 participants (mean age, 69.4 years; 59% female; 9% Hispanic/Latino; 14% Black/African American) from 29 ADRCs with ≥5 years of data and study visits after 2020 (e.g., baseline visits from January 2017‐December 2021). We used interrupted time series (ITS) analyses to assess the relationship of the pandemic on enrollment and calculated projected date of recovery of pre‐pandemic enrollment overall and by race, ethnicity, and sex.ResultsEnrollment dropped to 0% of pre‐pandemic levels in April 2020; through December 2021, enrollment recovered to only 46% of pre‐pandemic levels. Participants enrolled during the pandemic (vs pre‐pandemic) were less likely to be: women, cognitively normal, and able to live independently. They were slightly younger, slightly more educated, and more likely to: be married, be referred by a doctor, nurse, or other professional, and come in for a clinical or mixed clinical and research study evaluation (p’s<0.05). The two groups did not vary by race, ethnicity, living situation (alone or with others), or co‐participant characteristics. ITS demonstrated that the pandemic caused an immediate 79% drop in enrollment rate, with an estimated post‐pandemic increase in enrollment of 0.92%/month, leading to a projected recovery date of January 2026. Due to parallel pre‐ and post‐pandemic enrollment slopes among Black/African American participants, we could not predict a recovery date for this group. Projected recovery varied by ethnicity with Hispanic participant enrollment recovering earlier than non‐Hispanic participant enrollment (January 2022 vs. April 2027), largely because Hispanic participant enrollment was declining nearly 1.5%/month pre‐pandemic. Recovery date projections also varied by sex, with female participant enrollment recovering sooner than male participant enrollment (June 2025 vs. May 2027).ConclusionsStrategies to speed enrollment recovery should be developed and implemented, with special attention given to Black/African American and Hispanic enrollment. Funders and researchers should be aware of and account for ongoing COVID‐19 impact on ADRD research enrollment.