Development of the IRIS-AR strategy: an intervention to improve rates of accrual and retention for the VTE-PRO randomized controlled trial

The Venous Thromboembolism Prophylaxis (VTE-PRO) randomized trial is a pilot study evaluating the impact of extended-duration prophylaxis on venous thromboembolic events in patients undergoing lung cancer resection. Enrolled VTE-PRO participants self-inject either low-molecular weight heparin or a saline placebo for 30 days postoperatively. Study outcomes include feasibility, incidence of venous thromboembolism, and venous thromboembolism-related morbidity and mortality. Initial analyses demonstrated low rates of accrual and retention for the VTE-PRO pilot. Therefore, the purpose of the current study was to develop a knowledge translation intervention to improve VTE-PRO pilot trial accrual and retention.

Eligible participants were surveyed to identify the barriers to VTE-PRO participation. The Theoretical Domains Framework was used to categorize these barriers. Barriers were mapped to the capabilities, opportunities, and behavior (COM-B) behavioral change wheel to identify potential interventions to support trial accrual and retention. The resulting knowledge translation intervention was titled Inform, Remind, Involve and Support to improve Accrual and Retention (IRIS-AR). Key informant interviews with patients were held to refine and confirm the validity of identified barriers and perceived acceptability of the proposed IRIS-AR intervention. Institutional Review Board approval was granted for this study.

The resulting intervention included: information booklets and counseling sessions to identify unique participant challenges to trial participation (Inform); daily reminders to administer injections (Remind); involvement of family/caregivers in study processes (Involve); and leverage of an existing home-care nursing program to provide injection support when needed (Support). Twenty-six key informant participants were interviewed. The most common barriers to trial participation included lack of social support and fear of needle injection. Participants generally supported use of information booklets, involvement of family/caregivers, and support by a home-care nursing program; however, not all supported the use of daily reminders.

Developed using theory and integrated knowledge translation, the IRIS-AR presents a patient-centered intervention that leverages existing programs to promote trial engagement. The proposed strategy can likely be adapted to improve compliance with other patient-directed interventions.

ClinicalTrials.gov, NCT02334007 . Registered on 8 January 2015.