when one is not enough: randomisation by community

When One is Not Enough:Randomisation by Community

Neal Alexander

Why randomise by community or clusterHistorical development of cluster-randomised trials

Emphasis on infectious diseases

Recent and current contributions of TEG

Outline

Rationale: some interventions are difficult or impossible to allocate or assess individually

Freeman et al 2012 TMIH

Infections are ‘dependent happenings’

Pollock 1966 WHO monograph

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Cluster-randomized Trials in PubMed

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Cluster-randomized Trials in PubMed

Ferebee et al (1963): isoniazid prophylaxis in mental institutions

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Cluster-randomized Trials in PubMedThe Gambia Hepatitis Intervention Study (1987)

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Cluster-randomized Trials in PubMedBednets in Gambian villages (Snow et al 1988)

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Cluster-randomized Trials in PubMedIndirect effects (Halloran et al 1991)

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Cluster-randomized Trials in PubMed

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Management of STDs for HIV(Grosskurth et al 1995)

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Lancet 2009

Compares: community-wide isoniazid preventive therapy vs standard of TB care

1ary endpoint: TB incidence over 12 monthsResults unveiled at CROI 2012 by Fielding & Churchyard

Hostels Mine shaft

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inner scale: time in years, assuming three generations per year outer scale: generation number

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Design & Analysis of Trials to Compare Genetic Selection Coefficients

Spatial Analysis of ‘Spillover’

Anaya-Izquierdo et al in prep; trial in Kroeger et al BMJ 2002

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