Abstract
BACKGROUND: Recruitment for clinical trials and large-scale studies is challenging, especially for patients with complex conditions like chronic pain. Email recruitment has the potential to increase efficiency, to reduce costs, and to improve access for underrepresented patient populations. The objective of this study was to examine the effectiveness, efficiency, and equitability of email versus postal mail recruitment for the Learning to Apply Mindfulness to Pain (LAMP) study, a three-site clinical trial of mindfulness-based interventions for chronic pain. METHODS: Patients with chronic pain diagnoses were recruited from three United States Department of Veterans Affairs (VA) facilities using the VA electronic health record (EHR). Recruitment materials were sent using either postal mail (n = 7986) or email (n = 19,333). Patients in the email recruitment group were also mailed introductory postcards before any emails. Mailing addresses and email addresses were obtained from the EHR. Effectiveness was measured by the response rate of patients who logged into the secure LAMP study website. Efficiency was measured by the number of days from when the recruitment materials were sent to when patients logged into the LAMP portal as well as the estimated costs of each recruitment approach. To assess equitability, we examined whether email recruitment was less effective for underrepresented populations, based on demographic information from the EHR. RESULTS: Effectiveness-unadjusted response rates were greater for email versus postal-mail recruitment (18.9% versus 6.3%), and adjusted response rates were over three times greater for email recruitment (RR = 3.5, 95% CI 3.1-3.8) based on a multivariable analysis controlling for age, gender, race, ethnicity, rurality, and site. Efficiency-email recruitment had a significantly lower mean response time (1 day versus 8 days) and a lower cost. Equity-email recruitment led to higher response rates for all subpopulations, including older, non-White, Hispanic, rural, and female Veterans. CONCLUSIONS: Email recruitment is an effective, efficient, and equitable way to recruit VA patients to large-scale, chronic pain clinical trials. TRIAL REGISTRATION: Clinical Trial Registration Number: NCT04526158. Patient enrollment began on December 4, 2020.