Abstract 196: Does Health Status Influence the Willingness to Provide Informed Consent? Results from a Cardiac Arrest Trial Conducted Under Waiver of Informed Consent
Federal regulation 21 § CFR 50.24 allows an initial waiver of informed consent (IC) for treatment of certain medical emergencies but requires the consent process be initiated at the earliest feasible opportunity. In a recent out-of-hospital cardiac arrest (OHCA) trial conducted under 21 § CFR 50.24, data from public records were collected which shed light on whether the willingness to provide subsequent IC was associated with study outcomes. We hypothesized that IC was less likely to be obtained in subjects with significantly compromised health status.
A post-hoc analysis was conducted using data from a NIH-funded randomized, controlled OHCA clinical trial comparing active compression decompression CPR plus an impedance threshold device (ACD+ITD) with standard CPR. The primary endpoint was survival to hospital discharge (HD) with favorable neurologic function [Modified Rankin Scale (MRS) score <3]. The status of the consent process was tabulated for all subjects who survived to hospital admission. Unadjusted Fisher’s exact test and associated odds ratios were used to compare the MRS at HD by IC status.
Among a total study population of 1655 subjects, 457 survivors were admitted to the hospital, and 440 had known HD status (see table).
Survival with a MRS≤3 was significantly higher in subjects where IC was given: 35.0% vs 4.1%, p < 0.001. Sixteen of the 17 cases with missing MRS outcomes were in the IC denied group. Even if all were considered to have favorable outcomes, the resulting rate (21.1%) was less than that seen among subjects with IC given (p = 0.015).
Subjects who denied IC were significantly less likely to have favorable outcome. These findings suggest that some resuscitation trials may unknowingly under-represent those subjects with the worst prognoses in a target study population despite pre-specified inclusion and exclusion criteria, due to the unwillingness or inability of the subjects or their families to provide IC.
- © 2012 by American Heart Association, Inc.