The impact of learning about financial compensation on enrollment in Alzheimer's disease longitudinal research

Introduction: Recruitment and retention remains a major challenge in Alzheimer's disease research. This study examined the impact of describing potential financial compensation during recruitment on participant enrollment to a longitudinal cohort. Methods: Participant recruitment calls (N = 337) were randomized to either a compensation-mentioned group (n = 170) or a control group (n = 167). An intention-to-treat logistic regression assessed the effect of compensation on enrollment. Results: Of 320 analyzed, 124 (38.75%) enrolled. The intervention group's consent rate was lower than the control group's in intention-to-treat (-9.72 points; p = 0.074), per-protocol (-12.72 points; p = 0.026), and complier average causal effect analyses (-11.36 points; p = 0.72). Discussion: Disclosing compensation during recruitment may reduce enrollment, potentially due to perceptions that compensation conflicts with altruistic motives. However, this was observed in a highly educated sample; compensation may affect those with lower levels of education and socioeconomic status differently by helping offset participation burden, warranting further investigation.