Abstract WMP66: Enrollment in a Pre-hospital Stroke Trial: Common Reasons for Patient Non- Enrollment

Abstract

Background: Enrolling patients in the field is a promising strategy to facilitate entry of subjects within the first 1 to 2 hours after symptom onset into clinical trials for acute stroke treatment. The Field Administration of Stroke Therapy Magnesium (FAST-MAG) Trial is the first multicenter study to implement eliciting informed consent by cell phone between patients or their legally authorized representatives (LARs) and off- site enrolling physician-investigators. Call yield and profile of screen failures observed over the course of the study are reported. Methods: FAST-MAG is a phase 3 trial to evaluate field-initiated magnesium sulfate as a neuroprotective agent to improve the long-term functional outcome in acute stroke. The outcomes of these attempted enrollment calls from 362 participating ambulances to the eight central English and Spanish-speaking enrolling physician-investigators were tracked prospectively from 1/2012 to 1/2005. Results: Over seven years, 3,726 calls were made to enrolling physicians. Of these, 1478 (40%) resulted in trial enrollments. Among 2248 non-enrollment calls, the five most common reasons for were: physician’s determination of last known well time was longer than two hours (19%), pre-existing condition which could confound outcome evaluation (18%), patient deemed not competent to provide informed consent and no LAR available (12%), rapidly improving neurological deficit (9%), patient not English or Spanish speaking (6%). Phone connection difficulties accounted for only 2.7% of screen failures, whereas 4.2% were competent patients and 11% were LARs refusing participation. Yearly enrollment yeilds did not change significantly throughout the study Conclusion: Two of every five calls from the field to FM enrolling physicians resulted in trial enrollment. Enrollment yields were consistent throughout the study.