How to achieve model-robust inference in stepped wedge trials with model-based methods?
Wang B, Wang X, Li F. How to achieve model-robust inference in stepped wedge trials with model-based methods? Biometrics 2024, 80: ujae123. PMID: 39499239, PMCID: PMC11536888, DOI: 10.1093/biomtc/ujae123.Peer-Reviewed Original ResearchConceptsTreatment effect estimandsWorking correlation structureSandwich variance estimatorExchangeable working correlation structureFunction of calendar timeEffect estimandsVariance estimationLink functionStepped wedge trialEstimandsTheoretical resultsCorrelation structureWedge trialsEstimating equationsCluster randomized trialG-computationLinear mixed modelsInferencePotential outcomesMisspecificationEstimationEffective structureModel-based methodsGeneralized estimating equationsMixed modelsCausal interpretation of the hazard ratio in randomized clinical trials
Fay M, Li F. Causal interpretation of the hazard ratio in randomized clinical trials. Clinical Trials 2024, 21: 623-635. PMID: 38679930, PMCID: PMC11502288, DOI: 10.1177/17407745241243308.Peer-Reviewed Original ResearchProportional hazards assumptionHazard ratioHazards assumptionConstant hazard ratioRandomized clinical trialsMeasure of treatment effectTime-varying effectsEstimandsRate ratiosUntestable assumptionsIndividual-levelPopulation-level interpretationCausal effectsClinical trialistsIndividual-level interpretationsClinical trialsAssumptionsCausal interpretationAverage changeTreatment effectsPotential outcomesDoubly robust estimation and sensitivity analysis for marginal structural quantile models
Cheng C, Hu L, Li F. Doubly robust estimation and sensitivity analysis for marginal structural quantile models. Biometrics 2024, 80: ujae045. PMID: 38884127, DOI: 10.1093/biomtc/ujae045.Peer-Reviewed Original ResearchConceptsQuantile modelDistribution of potential outcomesEfficient influence functionPotential outcome distributionsDoubly robust estimatorsTime-varying treatmentsSequential ignorability assumptionSemiparametric frameworkIgnorability assumptionVariance estimationOutcome distributionInfluence functionRobust estimationPotential outcomesEfficient computationFunction approachTime-varying confoundersElectronic health record dataEstimationTreatment assignmentHealth record dataEffect of antihypertensive medicationEquationsRecord dataAntihypertensive medications