Statistical design and analysis issues for the ARDS Clinical Trials Network: the Coordinating Center perspective

We describe the statistical design principals for clinical trials conducted by the Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network that is funded by the National Heart Lung and Blood Institute. These include the definition of ARDS used by the network, the choice of measures of treatment efficacy, the choice of sample size, eligibility criteria, the choice of data to collect, stratification and randomization, the use of factorial trials and coenrollment of patients on more than one trial, early stopping for futility and efficacy, the choice of control group, the control of cointerventions, treatment administration and covariate adjustment.