2024
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 modelsMaintaining the validity of inference from linear mixed models in stepped-wedge cluster randomized trials under misspecified random-effects structures
Ouyang Y, Taljaard M, Forbes A, Li F. Maintaining the validity of inference from linear mixed models in stepped-wedge cluster randomized trials under misspecified random-effects structures. Statistical Methods In Medical Research 2024, 33: 1497-1516. PMID: 38807552, PMCID: PMC11499024, DOI: 10.1177/09622802241248382.Peer-Reviewed Original ResearchRandom effects structureVariance estimationComplex correlation structureRobust variance estimationFixed effects parametersDegrees of freedom correctionCluster randomized trialEstimates of standard errorsCorrelation structureRandom effectsStepped-wedge cluster randomized trialComprehensive simulation studyLinear mixed modelsStatistical inferenceRandom intercept modelSimulation studyMixed modelsMisspecificationValidity of inferencesRandom interceptContinuous outcomesEstimationComputational challengesIntercept modelStandard error
2020
A note on the estimation and inference with quadratic inference functions for correlated outcomes
Yu H, Tong G, Li F. A note on the estimation and inference with quadratic inference functions for correlated outcomes. Communications In Statistics - Simulation And Computation 2020, 51: 6525-6536. PMID: 36568127, PMCID: PMC9782733, DOI: 10.1080/03610918.2020.1805463.Peer-Reviewed Original ResearchQuadratic inference functionsInference functionScore equationsQuadratic inference function approachRegression parametersFinite samplesCombination of estimatorsGeneral settingEquationsCorrelated outcomesSimulation studyEstimatorFunction approachAnalytical insightsPopular methodInferenceSolutionMultiple setsMisspecificationSetFunctionEstimationAlternative solutionNoteParameters