Randomised controlled trials (RCTs) have been offered a privileged position in terms of the evidence base for preventive interventions for children, but practical and theoretical issues challenge this research methodology. This paper aims to address this issue.
This paper analyses practical and methodological issues of using RCTs within children's preventive services and presents the results of a qualitative study using data collected from parents who were asked to take part in an RCT of a preventive intervention.
Well recognised issues include the impossibility of blinding participants, the problem of identifying a pre‐eminent outcome measure for complex interventions, and problems with limiting access to equivalent interventions in real world settings. A further theoretical problem is the exclusion from RCTs of families who are most ready to change, resulting in a reduced level of intervention effectiveness. Qualitative evidence from one recent RCT suggests that this problem could be operating in some prevention trials. Increasing sample sizes can overcome some of these problems, but the cost of the necessarily huge trials becomes disproportionate to the intervention?
Given the limitations on RCTs in preventive settings, the paper argues their privileged position in terms of research evidence maybe undeserved.
