Sample size calculations for cluster randomised crossover trials in Australian and New Zealand intensive care research.
Crit Care Resusc
; 20(2): 117-123, 2018 Jun.
Article
em En
| MEDLINE
| ID: mdl-29852850
ABSTRACT
OBJECTIVE:
The cluster randomised crossover (CRXO) design provides an opportunity to conduct randomised controlled trials to evaluate low risk interventions in the intensive care setting. Our aim is to provide a tutorial on how to perform a sample size calculation for a CRXO trial, focusing on the meaning of the elements required for the calculations, with application to intensive care trials. DATA SOURCES We use all-cause in-hospital mortality from the Australian and New Zealand Intensive Care Society Adult Patient Database clinical registry to illustrate the sample size calculations.METHODS:
We show sample size calculations for a two-intervention, two 12-month period, cross-sectional CRXO trial. We provide the formulae, and examples of their use, to determine the number of intensive care units required to detect a risk ratio (RR) with a designated level of power between two interventions for trials in which the elements required for sample size calculations remain constant across all ICUs (unstratified design); and in which there are distinct groups (strata) of ICUs that differ importantly in the elements required for sample size calculations (stratified design).RESULTS:
The CRXO design markedly reduces the sample size requirement compared with the parallel-group, cluster randomised design for the example cases. The stratified design further reduces the sample size requirement compared with the unstratified design.CONCLUSIONS:
The CRXO design enables the evaluation of routinely used interventions that can bring about small, but important, improvements in patient care in the intensive care setting.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ensaios Clínicos Controlados Aleatórios como Assunto
/
Estudos Cross-Over
/
Cuidados Críticos
/
Pesquisa Biomédica
Tipo de estudo:
Clinical_trials
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limite:
Humans
País/Região como assunto:
Oceania
Idioma:
En
Revista:
Crit Care Resusc
Assunto da revista:
TERAPIA INTENSIVA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Austrália