chenaud and colleagues   are to be commended for their interest in achieving a better understanding of ' informed consent for research obtained during the intensive care unit stay ' . because intensive care medicine consumes an ever increasing percentage of total health care expenditure , research to define both its benefits and limitations is a moral imperative .
ironically , ethical concerns about informed consent for clinical studies in the intensive care unit ( icu ) are making this research increasingly difficult to conduct , especially in europe [ 2 - 5 ] .
the essential finding of this study is that research participants in the icu may have limited capacity to retain and remember elemental aspects of studies in which they have enrolled .
the authors showed that most icu patients , when questioned 10 to 12 days after having given their consent for participation in a study ( involving six blood draws over the course of a month ) , could not recall the purpose of the trial or its related risks .
these findings are similar to results previously reported by this same team of investigators in icu patients who underwent elective cardiac surgery .
what is the message of this study ? as emphasized by the authors , we must remember that informed consent for research is a process , not an event , and that we have an obligation to make sure that participants are continually reminded of the purposes and risks of a study and of their right to withdraw at any time .
however , does this study call into question the validity of the informed consent process itself ? the authors remind us of the three mandatory conditions for informed consent for research , as outlined in the belmont report : communication of information about the purposes and procedures involved in the trial , including its associated risks and benefits ; ensuring that subjects comprehend this information ; and ensuring that subjects are able to provide consent voluntarily . of note , none of these conditions require subjects to be able to recall this information at a later time .
in other words , whether subjects can recall elemental information at a later date has no bearing on whether the informed consent was valid .
in fact , there are good reasons why this should not be a factor in determining the quality of the informed consent process .
first , whether a patient has given a valid informed consent is a question that can only be asked and answered at the time when the consent is obtained .
events that happen later in the patient 's hospitalization can not make the consent more or less valid .
second , icu patients commonly experience neurologic derangements that limit their capacity for recall , caused both by their illnesses and by the medications they have been administered .
patients who have given their genuine informed consent under ideal circumstances may therefore be unable to recall the specifics at a later time .
third , the severity of the risks associated with the research may affect whether they can be recalled by subjects at a later time . for patients with a critical illness
, a request for six blood draws ( as in this study ) might have seemed trivial and not worth remembering .
the irrelevance of recall to the quality of informed consent can be illustrated by considering a hypothetical clinical trial that involved administration of a medication that would induce retrograde amnesia .
if subjects could theoretically provide fully valid consent for a study of this type , as i believe they could , then the capacity to recall the informed consent process clearly can not be a criterion for its validity . to sum up
, this study should remind us that informed consent is not just an event that occurs at the beginning of a study , but a process that needs to be continually revisited with patients during the course of a trial .
it would be a mistake , however , to claim that the inability of patients to recall elemental features of a trial at a later time is relevant to judging the quality and validity of the initial consent . as a final note ,
it is curious that this study on informed consent was itself conducted without informed consent .
the authors defend their decision not to obtain informed consent by noting that they obtained all of their data from the research database and from administrative files . clearly , however , the subjects had given consent only for their data to be used for the original purposes of the clinical research , and the investigators neither informed the subjects nor obtained their permission for these data to be used in a separate study for an entirely different purpose .
as one part of the study , the investigators asked the subjects questions about their recall of earlier conversations .
subjects who were asked these questions were not aware that they were participating in a research study and were not asked for their informed consent .
other information was taken from ' administrative files ' for research purposes without approval from an ethical review board .
although i acknowledge that it is very unlikely that any patients were harmed by their participation in this research , the question remains as to whether this study on the ethics of doing research itself satisfied the requirements of the belmont report .
the report provides an opportunity to discuss and debate a great many interesting issues , from the question of how we measure the quality of the informed consent process to the issue surrounding the ethical standards that should be applied to this type of research , and as such is very deserving of our interest and attention .
catherine chenaud , paolo merlani and bara ricou we are grateful to robert truog for his interesting and judicious comments on our report .
our research article   actually resulted from an interesting finding identified during the conduct of a study on inflammation , in which we had to re - contact the patients 10 to 12 days after their inclusion in order to plan for blood sampling on day 28 .
we realized that some patients did not remember having consented to participate in the study , its purpose , or its risks . in these cases
, we reviewed the study information and asked the patients whether they agreed to continue their participation in the study .
we therefore established an informed consent procedure based on a protocol to ensure that patients were adequately informed by all investigators .
we additionally noted whether patients read the information leaflet and asked questions during the procedure .
our objective in initiating this procedure was to ensure full adherence to the principle of autonomy .
we were surprised to discover that so many patients did not remember their inclusion in the study , its subject , or the related risks .
because problems stemming from the informed consent procedure may be frequent , we felt that it would be worthwhile to add to the debate on informed consent in critically ill patients by sharing our findings with the medical community .
it is not unusual for multiple reports to come from a single protocol , and this also applies to studies on informed consent conducting during studies on other issues .
some of these studies require informed consent only for the main study , whereas in others the need for informed consent is waived for all aspects of the study [ 8 - 11 ] .
we are not aware of a specific informed consent procedure being in place in these situations .
respect for fundamental ethical principles , embodied in the belmont report , is essential in protecting the human research subject .
it also is interesting , however , to balance the importance of informed consent , acquisition of knowledge , and study - related risks or burdens .
the most important safeguard for research subjects  more so than informed consent  is a conscientious , responsible , and caring investigator . in conclusion , we not only believe that ' the patients were not harmed by their participation ' , but we also feel that we tried to respect our patients ' autonomy by examining our informed consent procedure . by sharing our experience with the scientific community , we hope to contribute to improvements in protection of human research subjects in future studies conducted in critically ill patients .
 in the previous issue of critical care chenaud and colleagues found that most intensive care unit patients who had given informed consent for their participation in a clinical trial could not recall either the purpose of the trial or its related risks several days later . 
 these findings should remind us that informed consent is a process , not an event , but they should not be interpreted to mean that recall is , of itself , a useful criterion for evaluating either the validity or the quality of the informed consent process . on an entirely separate note , 
 the decision of the authors not to obtain informed consent for this study itself raises interesting questions about the ethics of doing research on the ethics of doing research . 
None
Authors' response
Abbreviations
Competing interests