Supplementary Material for: Simultaneous Ring Voice-over-Internet Phone System Enables Rapid Physician Elicitation of Explicit Informed Consent in Prehospital Stroke Treatment Trials Sanossian N. Starkman S. Liebeskind D.S. Ali L.K. Restrepo L. Hamilton S. Conwit R. Saver J.L. 10.6084/m9.figshare.5120866.v1 https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Simultaneous_Ring_Voice-over-Internet_Phone_System_Enables_Rapid_Physician_Elicitation_of_Explicit_Informed_Consent_in_Prehospital_Stroke_Treatment_Trials/5120866 <i>Background:</i> Cellular phone conversations between on-scene patients or their legally authorized representatives (LARs) and off-scene enrolling physician-investigators require immediate and reliable connection systems to obtain explicit informed research consent in prehospital treatment trials. <i>Methods:</i> The NIH Field Administration of Stroke Therapy – Magnesium (FAST-MAG) Trial implemented a voice-over-internet protocol (VOIP) simultaneous ring system (multiple investigator cell phones called simultaneously and first responder connected to call) to enable physician-investigators to elicit consent immediately from competent patients or LARs encountered by 228 ambulances enrolling patients in a multicenter prehospital stroke trial. For 1 month, the number, origin, duration, and yield of enrolling line calls were monitored prospectively. <i>Results:</i> Six investigators were connected to 106 enrolling line calls, with no identified unanswered calls. Thirty-five percent of new patient calls yielded an enrollment. The most common reasons for non-enrollment were last known well >2 h (n = 7) and uncon sentable patient without LAR available (n = 7). No non-enrollments were directly attributable to the VOIP system. In enrollments, consent was provided by the patient in 67% and a LAR in 33%. The duration of enrollment calls (mean ± SD: 8.4 ± 2.5 min, range 6–14) was longer than non-enrollment calls (5.5 ± 3.5, range 2–13; p < 0.001). The median interval from last known well to study agent start was 46 min, and 70% were enrolled within 60 min of onset. <i>Conclusions:</i> The simultaneous ring system was reliable and effective, permitting enrollment of a substantial number of patients within the first hour after stroke onset. VOIP cellular networks with simultaneous ring are a preferred means of facilitating consent in prehospital treatment trials. 2009-10-16 00:00:00 Prehospital trials Stroke Magnesium Informed consent Clinical trial