简介:Recurrenteventsdataandgaptimesbetweenrecurrenteventsarefrequentlyencounteredinmanyclinicalandobservationalstudies,andoftenmorethanonetypeofrecurrenteventsisofinterest.Inthispaper,weconsideraproportionalhazardsmodelformultipletyperecurrentgaptimesdatatoassesstheeffectofcovaxiatesonthecensoredeventprocessesofinterest.Anestimatingequationapproachisusedtoobtaintheestimatorsofregressioncoefficientsandbaselinecumulativehazardfunctions.Weexamineasymptoticpropertiesoftheproposedestimators.Finitesamplepropertiesoftheseestimatorsaredemonstratedbysimulations.
简介:Generalizedcase-cohortdesignhasbeenprovedtobeacost-effectivewaytoenhancetheefficiencyoflargeepidemiologicalcohort.Inthisarticle,weproposeaninferenceprocedureforestimatingtheunknownparametersinCox’sproportionalhazardsmodelingeneralizedcase-cohortdesignandestablishanoptimalsamplesizeallocationtoachievethemaximumpoweratagivenbudget.Thefinitesampleperformanceoftheproposedmethodisevaluatedthroughsimulationstudies.TheproposedmethodisappliedtoarealdatasetfromtheNationalWilm’sTumorStudyGroup.