Telling parents all relevant details might reduce recruitment of children to trials

BMJ 1996;313:362-363 (10 August)

Letters

Telling parents all relevant details might reduce recruitment of children to trials

EDITOR,--Charlotte Williamson argues that patients in clinicaltrials have "the right to know all relevant details about thesituation in which they find themselves."¹ If the investigatorsseeking consent can truly tell the patient that they do notknow which treatment is better then there is not a problem.Often, however, such equipoise does not exist because the investigatorssuspect that one treatment is superior but a randomised controlledtrial is still necessary. If the investigators share their suspicionswith the patient that one treatment may be superior then consentto randomisation may be less likely.

The Medical Research Council's trials of new treatments in childhoodacute lymphoblastic leukaemia have been running since 1970.Recruitment now includes over 95% of all cases of acute lymphoblasticleukaemia diagnosed in the United Kingdom, and five year survivalhas improved from 25% to over 70%.² Similarly, the United KingdomChildren's Cancer Study Group has been running studies in otherchildhood cancers since 1978.³ The outcome in children is improvedby their inclusion in a trial.⁴ Since 1985 the new experimentalarms have had a better outcome than standard treatment for acutelymphoblastic leukaemia. Earlier studies were marred by difficultieswith recruiting patients and decisions about closing the studies.

The demonstrable improvements in outcome have come about becauseclinicians preferred to run a series of trials rather than pursuetreatments selected on the basis of individual clinical judgment.Nevertheless, should parents and children giving informed consentto enter a randomised controlled trial in 1996 be made awarethat for the past decade the new experimental treatments havegiven better outcomes? Would this not constitute a "relevantdetail,"¹ even though recruitment to current trials might beadversely affected? Might this result in parents respondingthat, yes, they agree that randomised controlled trials haveimproved the outlook for children as a whole but they stillwant their child to have the new treatment?

Parents often cannot weigh up clearly the unknown benefits ofthe trial treatment against known side effects, particularlywhen differences in morbidity between the two arms of the trialare considerable. Is it acceptable to argue that the commongood will be served by including the child in a trial if uncertaintyexists in the parents' minds, or should the parents and childbe told of the track record of the experimental arms over thepast decade?⁵

Senior lecturer in child health Senior lecturer in child healthUniversity of Nottingham, Queen's Medical Centre, NottinghamNG7 2UH

Terence Stephenson, David A Walker