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Cluster randomised trials (CRTs) often face issues with missing data and treatment non-adherence. Guidelines such as CONSORT require that the numbers of clusters and individuals randomised, receiving treatment and analysed are reported, while newer guidelines go further (see for example the ICH 9 addendum on estimands), suggesting that an adherence-adjusted estimand is reported alongside an intention-to-treat estimate. For both analyses, missing data in covariates and outcome need to be handled appropriately as failure to do so can introduce bias in treatment effect estimates, leading to invalid inferences.

Multiple imputation has become a popular method to handle missing data, and instrumental variables methods can be used to obtain adherence-adjusted average treatment estimates (CACE). Both of these statistical techniques should reflect the hierarchical nature of CRT data.

In this talk, I will present multilevel multiple imputation for continuous and binary data, and then

present two approaches to obtain CACE for CRTs: (1)  cluster-level analysis two-stage least square method, with inferences at the cluster level, and (2) mixture models with random effects for individual level CACE.

I will illustrate these methods by re-analysing a CRT in UK primary health settings. The OPERA study trial, which studied the effect of a physiotherapist-led exercise intervention on depression and physical health in elderly residents of nursing home.

Forthcoming events

Oxford-Peking University Joint Symposium on Precision Medicine

Thursday, 19 September 2019, 10am to 6pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

CKB Workshop - Infections, immunity and cancer: aetiology and beyond

Friday, 20 September 2019, 1pm to 5pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

NDPH Seminar - Changing the way medical research is funded: Some lessons from Australia

Thursday, 26 September 2019, 4pm to 5pm @ Seminar rooms, BDI, Old Road Campus, OX3 7LF

Ethox/WEH Seminar - Reclaiming a Sense of Common Humanity: A Confucian Ethical Vision

Wednesday, 02 October 2019, 11am to 12.30pm @ Level 1 Ax Meeting Room, BDI, Old Road Campus, OX3 7LF

UVBO Seminar - Can wearable sensors and machine learning enhance our understanding of lifestyle health behaviours?

Thursday, 17 October 2019, 1pm to 2pm @ L1 Meeting room, Richard Doll Building, Old Road Campus, OX3 7LF

UVBO Seminar - Nutrient timing and human health

Thursday, 24 October 2019, 1pm to 2pm @ School of Anthropology, 61 Banbury Road, OX2 6PE