Deferred Consent for Randomized Controlled Trials in Emergency Care Settings

Abstract

BACKGROUND: There is limited experience in using deferred consent for studies involving children, which was legalized in the United Kingdom in 2008. We aimed to inform future studies by evaluating consent rates and reasons for nonconsent in a large randomized controlled trial in pediatric intensive care. METHODS:In the CATCH trial, eligible children from 14 PICUs in England and Wales were randomly assigned to 3 types of central venous catheters. To avoid delay in treatment, children admitted on an emergency basis were first randomly assigned to a trial central venous catheter, and we deferred seeking consent to use already collected data and blood samples until after stabilization.RESULTS: Consent was obtained for 984/1358 (72%) of children admitted on an emergency basis. Failure to obtain consent resulted mainly from a lack of opportunity (early discharge or transfer) for survivors and difficulties in seeking consent for children who died. For admissions where there was an opportunity to approach (n = 1298), inclusion rates differed according to survival status: 93/984 (9%) of consented patients died, compared with 58/314 (18%) of nonconsented patients. For children admitted on an emergency basis whose families were approached, 984/1178 (84%) provided deferred consent (n = 15 sites), compared with 441/641 (69%) of children admitted on an elective basis who were approached for prospective consent (n = 9 sites).CONCLUSIONS: Design of emergency randomized controlled trials should balance the potential burden that seeking consent in difficult situations may cause against risk of bias by disproportionately excluding children who die or are transferred. Ethics committees could consider approving the use of already collected data when best efforts to obtain deferred consent are unsuccessful.WHAT'S KNOWN ON THIS SUBJECT: Deferral of consent avoids delaying emergency interventions while ensuring consent to ongoing participation and use of data. Deferred consent is particularly important for enabling trials in pediatric settings, where many medicines and devices are unlicensed and untested for use. WHAT THIS STUDY ADDS:Approaches for seeking deferred consent should balance the potential burden of obtaining consent against risk of bias due to outcome-related attrition. Ethics committees could consider approving data use when best efforts to obtain deferred consent are met with no response.

CATheter Infections in CHildren (CATCH): a randomised controlled trial and economic evaluation comparing impregnated and standard central venous catheters in children

“…In the CATCH trial, deferred consent was obtained from 84% of families who were approached. 60 The use of deferred consent allowed us to recruit emergency admissions, reach the target sample size within the available funding and provide results that are convincing to clinicians working in the emergency setting. Participation in the CATCH trial after the intervention had taken place represented a minimal burden to children (use of data already collected and follow-up data collection only).…”

“…Detailed reasons for non-consent are reported elsewhere. 60 Numbers enrolled by site and by month are provided in Appendix 2 (see Table 24 and Figure 13). …”

“…We propose that, in future, ethics committees allow use of linked administrative records without consent, when reasonable efforts to obtain consent have been made or are not feasible or are considered to be harmful. 60 There is still uncertainty about the most appropriate ways to approach bereaved parents of children randomised in an emergency. 105 Our experience in the CATCH trial highlights that further in-depth research should be incorporated into the design of emergency trials involving populations with high mortality rates.…”

What are research nurses' experiences of obtaining consent from or for patients participating in emergency care research? A qualitative review

“…For example, some research nurses chose not to approach patients who had suffered an acute stroke because they felt they were frail and unable to cope with the burden of participation. Similarly, some consultants and research nurses thought recruitment (of children) in emergency situations was an additional burden for parents and this had an adverse effect on recruitment (Harron et al, ). However, this was not evident in all studies (Woolfall et al,).…”

Economic methods used in health technology assessment

“…Nine studies were randomized controlled trials (Ashby et al, 2014;Downing et al, 2015;Harron et al, 2016;Lall et al, 2015;Murray et al, 2014;Rosenthal et al, 2015;Smulders et al, 2016;Walter et al, 2015), usually comparing clinical benefi ts and cost-effectiveness of the traditional device with a new developed one, one study was a prospective study (Dozet et al, 2016), using a cost-minimization analysis for societal impact reasons, and one was a survey (Heintz et al, 2016), conducted among 33 European countries, which are involved in the European Network for Health Technology Assessment. The aim of this survey was to provide a general framework for economic evaluation at a European level.…”