Secondary analysis of electronic opt-out consent in pragmatic research: A study design method to diversify clinical trials?

We conducted a multi-center pragmatic trial of a low-risk intervention focused on medication adherence using an opt-out consent approach, where patients could opt out by letter and then electronically. We focus on the cohort after opt-out by mail. Here, we describe that 8% of patients opted out electronically, resulting in a 92% participation rate. Patients who self-identify as Black or Hispanic were less likely to opt out in the study, and half the study cohort was female. This demographic data is useful for planning future trials employing this approach.