To compare healthcare survey response rates using two widely utilized recruitment methods: email and the electronic health record (EHR) patient portal.

Adults with a prior history of any bariatric surgery were randomly assigned (1:1) to receive a survey invitation via email or through the EHR patient portal. A second reminder was sent using the same method. A third invitation used a crossover approach, switching to the alternate method. We compared survey completion rates, changes in research preference status, and time to survey completion. Predictors of response were assessed using multivariable logistic regression.

The email group had a 9.9% response rate after the first invitation and 6.5% after the second. The EHR portal group had 8.4% and 4.5% response rates, respectively. Following crossover, the third invitation yielded a 4.4% response for those switched to the EHR portal and 7.5% for those switched to email. The EHR portal group was 27% less likely to complete the survey compared to the email group. Respondents were more likely to be female, non-Hispanic, White, have a recent healthcare encounter, and have recently logged into the portal. Median time to completion was under 24 hours in both groups, with over two-thirds of responses received on the day of or the day after the invitation. A change in research preference status was observed in 2.5% of email and 4.0% of portal participants.

Email-based recruitment yielded higher response rates than EHR portal-based recruitment, with most responses occurring shortly after invitation.