Subject Retention in Prehospital Stroke Research Using a Telephone-Based Physician-Investigator Driven Enrollment Method

Background and Purpose: Subject retention into clinical trials is vital, and prehospital enrollment may be associated with higher rates of subject withdrawal than more traditional methods of enrollment. We describe rates of subject retention in a prehospital trial of acute stroke therapy. Methods: All subjects were enrolled into the NIH Field Administration of Stroke Therapy-Magnesium (FAST-MAG) phase 3 clinical trial. Paramedics screened eligible subjects and contacted the physician-investigator using a dedicated in-ambulance cellular phone. Physician-investigators obtained explicit informed consent from the subject or on-scene legally authorized representative (LAR) who reviewed and signed a consent form. Exception from informed consent (EFIC) was utilized in later stages of the study. Results: There were 1,700 subjects enrolled; 1,017 provided consent (60%), 662 were enrolled via LAR (39%), and 21 were enrolled via EFIC (1%). Of the 1,700 patients, 1,413 (83%) completed the 90-day visit, 265 (16%) died prior to the 90-day visit, and 22 (1.3%) withdrew from the study before completion. There were no differences in rates of withdrawal by method of study enrolment, i.e., self-consent (n = 14), 1.4%; LAR (n = 8), 1.2%; EFIC (n = 0) 0%. Conclusion: There was a high rate of retention when subjects were enrolled into prehospital stroke research using a phone-based method to obtain explicit consent.

Abstract WP256: High Rate of Subject Retention into Prehospital Stroke Research with Telephone-based Physician-investigator Driven Enrollment

Background: Explicit informed consent for prehospital research can be achieved by physician-investigators using cellular phones to communicate with potential subjects or legally authorized representatives (LAR). Subject retention into clinical trials is vital, and prehospital enrollment may be associated with higher rates of subject withdrawal than more traditional methods of enrollment. Objective: To describe rates of subject retention in a prehospital trial of acute stroke therapy and to determine if method of consent was associated with subject withdrawal. Methods: All subjects were enrolled in the NIH Field Administration of Stroke Therapy-Magnesium (FAST-MAG) clinical trial. Paramedics screen eligible subjects, contact the physician-investigator using dedicated in-ambulance cellular phone. Physician-investigators obtain explicit informed consent from the subject or on-scene LAR. In the later years of study, enrolment under exception from informed consent (EFIC) was permitted. The consent provider was given a consent form, which they reviewed with the physician investigator on the phone and signed prior to study initiation. Retention, defined as study subject completion without withdrawal. Results: There were 1700 subjects enrolled; 1,017 provided consent (60%), 662 enrolled via LAR (39%) and 21 via EFIC (1%). Of 1,700 patients, 1413 (83%) completed the 90-day cvisit, 265 (16%) died prior to the 90-day visit and 22 (1.3%) withdrew from the study before completion. Of the 22 cases what withdrew, 11 were lost to follow-up, 11 had the patient or LAR withdraw consent. There were no differences in rates of withdrawal by method of study enrolment: Self consent (n=14) 1.4%, LAR (n=8) 1.2%, EFIC (n=0) 0%. Potential factors related to higher rates of withdrawal were evaluated including language of consent (Spanish 4/165, 2.1%, English 18/1248, 1.2%), but none were significant. The most common reason for withdrawal of consent was family objection to continued participation in research. Conclusion: There was a high rate of retention when subjects were enrolled into prehospital stroke research using a phone-based method to obtain explicit consent. We were not able to identify factors associated with study withdrawal, likely due to high retention.

Bupropion Reduces Some of the Symptoms of Marihuana Withdrawal in Chronic Marihuana Users: A Pilot Study

Bupropion's (Zyban® SR) effectiveness to treat symptoms experienced in marihuana withdrawal was tested in a double-blind, placebo-controlled study with chronic, heavy marihuana users. Participants maintained their usual marihuana intake until Quit Day after which they were required to cease intake of THC products for 14 days. A Withdrawal Discomfort Score revealed that for 7 days immediately following cessation, placebo-treated subjects reported more symptoms than bupropion-treated subjects. Self-reported craving for marihuana increased for the placebo-treated group but not for those treated with bupropion. Measures of sleep and cognitive performance were not different between the two groups. Participants in the bupropion treatment arm were more likely to complete the study than those randomized to the placebo arm (50% completion for bupropion vs. 33% completion for placebo). These results suggest that bupropion may be useful for alleviating marihuana withdrawal symptoms and be useful in subject retention during long-term cessation programs.