• Centre for Primary Care and Public Health
• Clinical effectiveness group
• Pragmatic clinical trials unit
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  • Responsibility of the chief investigator
  • Methodology
    • Sources of variation in ICC values
    • NIHR NCCRCD research methods
    • Modelling process data from the diabetes manual
    • Issues in cluster randomised trials in nursing homes
    • Issues in cluster randomised trials in dentistry
    • Covariates in cluster randomised trials
    • Cascade diagrams
    • Trials comparing diagnostic tests
    • Developing simple appropriate sample size formulae for ordinal, count or time to event outcomes in cluster randomised trials (PhD)
    • Interim sample size calculations for CRTs
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Methodology

Methodological research undertaken by members of the PCTU includes research on cluster randomised trials and complex interventions.

Current projects

Cascade diagrams

Developing simple appropriate sample size formulae for ordinal, count or time to event outcomes in cluster randomised trials (PhD)

Interim sample size calculations for cluster randomised trials

Issues in cluster randomised trials in nursing homes: a systematic review
(part of NIHR NCCRCD research methods training fellowship October 2009- Sept 2013)

Covariates in cluster randomised trials

Trials comparing diagnostic tests

Completed projects

Issues in cluster randomised trials in dentistry: a systematic review

Sources of variation in ICC values

Modelling process data from the Diabetes Manual trial to inform the design of future complex interventions aimed at people with diabetes

Selected publications

Eldridge SM, Ukoumunne OC, Carlin JB. The Intra-Cluster Correlation Coefficient in Cluster Randomized Trials: A Review of Definitions. International Statistical Review 2009, 77, 3, 378–394.

Eldridge S, Kerry S, Torgerson DJ. Bias in identifying and recruiting participants in cluster randomised trials: what can be done? BMJ. 2009 Oct 9;339:b4006

Hooper R. The Bayesian interpretation of a P-value depends only weakly on statistical power in realistic situations. J Clin Epidemiol 2009;62:1242-1247.

Eldridge S, Ashby D, Bennett C, Wakelin M, Feder G. Internal and external validity of cluster randomised trials: systematic review of recent trials. BMJ 2008; 336(7649):876-880.
Eldridge SM, Ashby D, Kerry S. Sample size calculations for cluster randomized trials: effect of coefficient of variation of cluster size and analysis method. Int. J. Epidemiol. 2006 Oct;35(5):1292-300

Eldridge S, Spencer A, Cryer C, Parsons S, Underwood M, Feder G. Modelling a complex intervention is an important precursor to trial design: lessons from studying an intervention to reduce falls-related injuries in older people. J Health Serv.Res Policy 2005;10:133-142.

Eldridge SM. Ashby D. Feder GS. Informed patient consent to participation in cluster randomised trials: an empirical exploration of trials in primary care. Clinical Trials 2005; 2: 91-98

Eldridge SM, Ashby D, Feder GS, Rudnicka AR, Ukoumunne OC. Lessons for cluster randomised trials in the twenty-first century: a systematic review of trials in primary care. Clinical Trials 2004;1:80-90.