BackgroundInstitutional review boards (IRBs) are given discretion to interpret and apply the federal regulations governing the protection of human subjects in research.ObjectiveTo determine the extent of the variability among different IRBs on their approved research practices and informed consent forms within the context of a multicenter trial that used a common protocol.DesignDescriptive analysis of survey information and informed consent forms.Setting and ParticipantsSixteen IRBs from the institutions participating in a multicenter trial comparing lower vs. traditional tidal volume ventilation in patients with acute lung injury.MeasurementsAnalysis of survey information on IRBs’ approved research practices. Analysis of informed consent forms for the presence and the adequacy of description of each basic element of informed consent specified in the federal regulations. Reading levels of informed consent forms.Main ResultsSurveys and IRB-approved consent forms were obtained from all of the contacted IRBs (n = 16). Variability was observed among several of the research practices; one IRB waived the requirement for informed consent, five IRBs permitted telephone consent, and three IRBs allowed prisoners to be enrolled. Three consent forms contained all of the basic elements of informed consent outlined in the federal regulations, and 13 forms had varying numbers of these elements absent (six forms without one element, four without two, one without three, and two without four). Reading levels of the consent forms ranged from grades 8.2 to 13.4 (mean ± sd was 11.6 ± 1.2 grade level).ConclusionsWithin a multicenter trial, IRBs reviewing a common protocol varied in several of their approved research practices and in the extent to which the basic elements of informed consent were included in their consent forms.