Discussion

Multiple factors including lack of availability of the legal guardians, language issues and child protective services involvement resulted in only half the eligible patients being approached for consent. It is difficult to determine if this is consistent with other studies as it has not been explicitly reported in previous paediatric critical care studies.5 ,14 ,15 However, this has important practical and ethical implications for both the interpretation of the results of this study as well as for the design, budget and implementation of future studies.

Consent for this non-therapeutic study was only 42% which is significantly lower than the consent rates seen with previous therapeutic studies (66–89%) with similar requirements for early recruitment.5 ,14 ,15 These studies also involved critically ill children and many of the same sites as this current study, but interestingly, also all provided the potential for direct benefit to the participating child. The AIP study, however, did not, and therefore, willingness to participate would have been based primarily on altruism. Only 1% of non-consenters in the AIP study stated that they did not wish to participate as there was no direct benefit to their child, but it is entirely possible that parents’ spontaneously expressed comments do not accurately reflect their true reasons for non-participation in research. In survey-based studies of theoretical scenarios, parents have stated a variable willingness to participate in research for altruistic reasons ranging from 32.4%16 to 72%.17 In the only two studies to spontaneously record parents’ stated reasons for consent refusal, lack of benefit to their child was not volunteered as a reason.2 ,10

The most commonly volunteered reason for consent refusal was that parents felt too overwhelmed. This finding is supported by others who have documented that parents suffer significant stress and anxiety when their children are admitted to intensive care.18 This raises the question of whether researchers can truly obtain informed consent in an intensive care environment, and the literature is divided on this issue. Two studies have suggested that despite a high level of anxiety, 90% of parents felt they had made an informed decision and understood the elements of a neonatal intensive care study,19 and 93% of parents demonstrated fair or excellent comprehension of their child's medical issues within the first 24 h following admission to the PICU.20 However, two other studies found that between 7.8%21 and 12%22 of parents had no recollection of the study they had agreed to participate in or of signing the consent form. Given the difficulties in obtaining informed consent from parents in a stressful environment, one potential approach might be to limit research in the PICU. However, both the Tri-Council Guidelines and the Oveida Convention emphasise the need for research to advance medical care, and for researchers to not automatically exclude those who cannot provide consent for themselves. The literature supports the fact that despite these recommendations, children are less likely to be enrolled in acute care clinical research studies,9 and that there is a lack of adequate medical research in children.23

Given the paucity of high-quality research in children, and the difficulties in obtaining informed consent in paediatric critical care studies, it behooves the research community (researchers, ethics boards, clinicians and the public) to explore options to improve this. Parents themselves have provided several suggestions for ways to decrease their stress levels in the intensive care unit including a visit from a pastor, consistency of nursing and the ability to talk about the possibility of their child's death.7 It has also been suggested that introduction of the research assistant to the parents by a member of the child's healthcare team may decrease parental stress and increase the likelihood of consent,2 and would be a simple procedure to implement. Another (more complicated) option is the use of deferred consent for critical care studies which is covered under the sections governing Research in Emergency Health Situations in the Tri-Council Guidelines and the Food and Drug Administration Guidelines in the USA. Deferred consent permits research ethics boards to allow research in health emergencies without the free and informed consent of the subject or their authorised third party, as long as several carefully laid out principles are followed. Deferred consent has rarely been used in paediatric critical care despite evidence suggesting that parents would support this model in certain cases.24

Strengths of this are that it is the largest study to systematically document the reasons for non-participation of eligible patients, and to record the stated reasons why legal guardians declined participation in a clinical research study within the PICU. Limitations of this study include that the stated reasons for declining consent may not accurately reflect the real reasons why legal guardians did not wish to participate. However, this is true of all survey studies which still yield useful information if interpreted within the context of this limitation. Another limitation of this study was that information on why legal guardians agreed to participate was not collected which would be an interesting area for future research. Finally, this study was conducted in paediatric critical care units in Canada and, therefore, may not be generalisable to other patient care settings or countries.