CRPL Research Methods Seminar Series - Kitty Parker (University of Exeter)

Cluster randomised trials for evaluating school-based interventions to improve health outcomes in pupils

Speaker: Kitty Parker

Cluster randomised trials (CRTs) are studies in which groups of individuals are randomised to trial arms rather than individuals themselves. For example, these ‘clusters’ can be hospitals, GPs surgeries or geographical locations such as towns. The CRT design is commonly used in health care research when interventions must be delivered at the cluster level and to minimise contamination of the trial arms that might otherwise occur when individuals are randomised. Unlike individually randomised trials, outcomes for individuals in the same cluster are much more likely to be similar than those from different clusters. Therefore, the usual methods for sample size calculation and statistical analysis cannot be used as they assume statistical independence and may produce results that exaggerate evidence of the true effect of the intervention.

CRTs are becoming increasingly relevant for evaluating interventions delivered in school settings for improving the health of children. Schools are a convenient setting for health interventions targeted at children and the CRT design respects the clustered structure in schools (i.e., pupils within classrooms within schools). Some of the methodological challenges of CRTs, such as ethical considerations for enrolment of children into trials and how best to handle the analysis of data if pupils change schools (clusters), may be more salient for the school setting. A better understanding of the characteristics and methodological considerations of school-based CRTs of health interventions would inform the design of future similar studies.

This talk will provide a further introduction to the topic area, outline the rational for this thesis and the objectives we hope to achieve. Methods and preliminary results from our first study, a systematic review, will be presented. To our knowledge this is the only systematic review to focus specifically on the characteristics and methodological practices of CRTs delivered in schools to evaluate interventions for improving health outcomes in pupils in the UK.

This event will take place on Zoom, please contact the event organiser for the meeting link.