2024
Assessing treatment effect heterogeneity in the presence of missing effect modifier data in cluster-randomized trials
Blette B, Halpern S, Li F, Harhay M. Assessing treatment effect heterogeneity in the presence of missing effect modifier data in cluster-randomized trials. Statistical Methods In Medical Research 2024, 33: 909-927. PMID: 38567439, PMCID: PMC11041086, DOI: 10.1177/09622802241242323.Peer-Reviewed Original ResearchConceptsMultilevel multiple imputationHeterogeneous treatment effectsCluster randomized trialPotential effect modifiersMultiple imputationAssess treatment effect heterogeneityEffect modifiersTreatment effect heterogeneityComplete-case analysisMissingness mechanismIntracluster correlationSimulation studyUnder-coverageRandomized trialsEffect heterogeneityHealth StudyTreatment effectsContinuous outcomesClinical practiceImputationModel specificationMissingnessData methodsModified dataTrials
2023
Planning stepped wedge cluster randomized trials to detect treatment effect heterogeneity
Li F, Chen X, Tian Z, Wang R, Heagerty P. Planning stepped wedge cluster randomized trials to detect treatment effect heterogeneity. Statistics In Medicine 2023, 43: 890-911. PMID: 38115805, DOI: 10.1002/sim.9990.Peer-Reviewed Original ResearchTreatment effectsWedge designTreatment effect heterogeneityPatient subpopulationsLumbar imagingTreatment effect analysisWedge clusterWedge trialCandidate interventionsSubgroup treatment effectsCovariate adjustmentTrialsEffect heterogeneityAverage treatment effectRigorous evaluationFormal evaluationSample sizeResearch designInformative cluster size in cluster-randomised trials: A case study from the TRIGGER trial
Kahan B, Li F, Blette B, Jairath V, Copas A, Harhay M. Informative cluster size in cluster-randomised trials: A case study from the TRIGGER trial. Clinical Trials 2023, 20: 661-669. PMID: 37439089, PMCID: PMC10638852, DOI: 10.1177/17407745231186094.Peer-Reviewed Original ResearchConceptsCluster-randomised trialCluster-level summariesAcute upper gastrointestinal bleedingExchangeable correlation structureRed blood cell transfusionEQ-5D VAS scoreMixed-effects modelsUpper gastrointestinal bleedingBlood cell transfusionMixed effects modelsTreatment effectsCell transfusionGastrointestinal bleedingIschemic eventsVAS scoresOdds ratioMost outcomesTRIGGER trialTreatment effect estimatesEffect estimatesInformative cluster sizeTrialsOutcomesParticipant outcomesCorrelation structureSample size considerations for assessing treatment effect heterogeneity in randomized trials with heterogeneous intracluster correlations and variances
Tong G, Taljaard M, Li F. Sample size considerations for assessing treatment effect heterogeneity in randomized trials with heterogeneous intracluster correlations and variances. Statistics In Medicine 2023, 42: 3392-3412. PMID: 37316956, DOI: 10.1002/sim.9811.Peer-Reviewed Original ResearchConceptsGroup treatment trialsTreatment effect modificationRandomized trialsTreatment trialsEffect modificationEffect modifiersIntracluster correlation coefficientIndividual-level effect modifiersStudy armsTreatment effect heterogeneityOutcome observationsContinuous outcomesTrialsGroup treatmentTreatment effectsOutcome varianceEffect heterogeneityIntracluster correlationSample sizeSample size formulaA scoping review described diversity in methods of randomization and reporting of baseline balance in stepped-wedge cluster randomized trials
Nevins P, Davis-Plourde K, Pereira Macedo J, Ouyang Y, Ryan M, Tong G, Wang X, Meng C, Ortiz-Reyes L, Li F, Caille A, Taljaard M. A scoping review described diversity in methods of randomization and reporting of baseline balance in stepped-wedge cluster randomized trials. Journal Of Clinical Epidemiology 2023, 157: 134-145. PMID: 36931478, PMCID: PMC10546924, DOI: 10.1016/j.jclinepi.2023.03.010.Peer-Reviewed Original ResearchConceptsStepped-wedge clusterIndividual-level characteristicsMethod of randomizationCross-sectional designControl armBaseline imbalancesCohort designMedian numberElectronic searchPrimary analysisBaseline balanceStudy designPrimary reportsBaselineTrialsIntervention conditionSW-CRTsRandomizationReportingHealth equity considerations in pragmatic trials in Alzheimer's and dementia disease: Results from a methodological review
Nicholls S, Al‐Jaishi A, Niznick H, Carroll K, Madani M, Peak K, Madani L, Nevins P, Adisso L, Li F, Weijer C, Mitchell S, Welch V, Quiñones A, Taljaard M. Health equity considerations in pragmatic trials in Alzheimer's and dementia disease: Results from a methodological review. Alzheimer's & Dementia Diagnosis Assessment & Disease Monitoring 2023, 15: e12392. PMID: 36777091, PMCID: PMC9899766, DOI: 10.1002/dad2.12392.Peer-Reviewed Original Research
2022
Designing three-level cluster randomized trials to assess treatment effect heterogeneity
Li F, Chen X, Tian Z, Esserman D, Heagerty PJ, Wang R. Designing three-level cluster randomized trials to assess treatment effect heterogeneity. Biostatistics 2022, 24: 833-849. PMID: 35861621, PMCID: PMC10583727, DOI: 10.1093/biostatistics/kxac026.Peer-Reviewed Original ResearchPragmatic clinical trial design in emergency medicine: Study considerations and design types
Gettel CJ, Yiadom MYAB, Bernstein SL, Grudzen CR, Nath B, Li F, Hwang U, Hess EP, Melnick ER. Pragmatic clinical trial design in emergency medicine: Study considerations and design types. Academic Emergency Medicine 2022, 29: 1247-1257. PMID: 35475533, PMCID: PMC9790188, DOI: 10.1111/acem.14513.Peer-Reviewed Original ResearchConceptsPragmatic clinical trialsClinical trial designTrial designReal-world clinical practicePragmatic clinical trial designElectronic health recordsEmergency departmentClinical trialsStudy design typeClinical practiceStudy typeTrial componentsHealth recordsEmergency medicineEmergency medicine investigatorsHuman subjects concernsInvestigatorsStudy findingsStudy considerationsTrialistsTrialsGeneralizing Trial Evidence to Target Populations in Non-Nested Designs: Applications to AIDS Clinical Trials
Li F, Buchanan AL, Cole SR. Generalizing Trial Evidence to Target Populations in Non-Nested Designs: Applications to AIDS Clinical Trials. Journal Of The Royal Statistical Society Series C (Applied Statistics) 2022, 71: 669-697. PMID: 35968541, PMCID: PMC9367209, DOI: 10.1111/rssc.12550.Peer-Reviewed Original ResearchAIDS Clinical Trials GroupTarget populationClinical Trials GroupComparative effectiveness evidenceTreatment effectsRandomized trialsTrial evidenceClinical trialsTrial groupHIV interventionsACTG trialsTrial participantsTrial designPropensity scoreEffectiveness evidenceTrialsAIDS clinical trialsSpecified populationPopulationAverage treatment effectMost casesHIVEvidenceRegressionEthical considerations within pragmatic randomized controlled trials in dementia: Results from a literature survey
Nicholls SG, Carroll K, Nix HP, Li F, Hey SP, Mitchell SL, Weijer C, Taljaard M. Ethical considerations within pragmatic randomized controlled trials in dementia: Results from a literature survey. Alzheimer's & Dementia: Translational Research & Clinical Interventions 2022, 8: e12287. PMID: 35509502, PMCID: PMC9060321, DOI: 10.1002/trc2.12287.Peer-Reviewed Original ResearchEthical considerationsEthical protectionsVulnerable participantsConsent approachResearch participantsResearch participationPatient's capacityAlzheimer's diseaseEthics approvalSearch of MEDLINEHealth care professionalsCapacity assessmentStudy populationEligible reportsTrial settingsConsentVulnerable groupsDementiaTwo-thirdsConsiderationDiseaseTrialsParticipantsExtracted informationMention
2021
A note on semiparametric efficient generalization of causal effects from randomized trials to target populations
Li F, Hong H, Stuart E. A note on semiparametric efficient generalization of causal effects from randomized trials to target populations. Communication In Statistics- Theory And Methods 2021, 52: 5767-5798. PMID: 37484707, PMCID: PMC10361688, DOI: 10.1080/03610926.2021.2020291.Peer-Reviewed Original ResearchMethodological challenges in pragmatic trials in Alzheimer’s disease and related dementias: Opportunities for improvement
Taljaard M, Li F, Qin B, Cui C, Zhang L, Nicholls SG, Carroll K, Mitchell SL. Methodological challenges in pragmatic trials in Alzheimer’s disease and related dementias: Opportunities for improvement. Clinical Trials 2021, 19: 86-96. PMID: 34841910, PMCID: PMC8847324, DOI: 10.1177/17407745211046672.Peer-Reviewed Original ResearchConceptsPragmatic trialAlzheimer's diseasePrimary outcomeSample size calculationGroup treatment trialsPairs of reviewersDementia researchSize calculationCluster Randomized TrialGroup treatment designRandomized trialsTreatment trialsIntracluster correlationMethodological qualityTrial reportsBaseline assessmentDiseaseTrialsDementiaKey methodological characteristicsOutcomesType IMethodological quality indicatorsUnique methodological challengesSame individualswdpwr: A SAS macro and an R package for power calculations in stepped wedge cluster randomized trials
Chen J, Zhou X, Li F, Spiegelman D. swdpwr: A SAS macro and an R package for power calculations in stepped wedge cluster randomized trials. Computer Methods And Programs In Biomedicine 2021, 213: 106522. PMID: 34818620, PMCID: PMC8665077, DOI: 10.1016/j.cmpb.2021.106522.Peer-Reviewed Original ResearchConceptsWedge clusterIntracluster correlation coefficientContinuous outcomesCross-sectional cohortBinary outcomesExchangeable correlation structureWedge designPublic health intervention evaluationsHealth services researchClosed cohort designPower calculationCohort designClosed cohortStudy designIntracluster correlationIntervention evaluationNeeds of investigatorsOutcomesTrialsCohortServices researchInvestigatorsPrevious studiesSWDSample size and power considerations for cluster randomized trials with count outcomes subject to right truncation
Li F, Tong G. Sample size and power considerations for cluster randomized trials with count outcomes subject to right truncation. Biometrical Journal 2021, 63: 1052-1071. PMID: 33751620, PMCID: PMC9132617, DOI: 10.1002/bimj.202000230.Peer-Reviewed Original ResearchConceptsCluster Randomized TrialPrimary outcomeGroup-based interventionRandomized trialsHealth StudySuch trialsPublic health studiesRight truncationTrialsOutcomesVector-borne diseasesCountSample size formulaAnalysis of CRTsPower calculationPopulation-level effectsSample sizeSize formulaClosed-form sample size formulaMarginal modeling approachMalariaDisease
2020
Statistical Considerations for Embedded Pragmatic Clinical Trials in People Living with Dementia
Allore HG, Goldfeld KS, Gutman R, Li F, Monin JK, Taljaard M, Travison TG. Statistical Considerations for Embedded Pragmatic Clinical Trials in People Living with Dementia. Journal Of The American Geriatrics Society 2020, 68: s68-s73. PMID: 32589276, PMCID: PMC7396162, DOI: 10.1111/jgs.16616.Peer-Reviewed Original ResearchConceptsEmbedded Pragmatic Clinical TrialsPragmatic clinical trialsClinical trialsAlzheimer's diseaseImbedded Pragmatic Alzheimer's DiseaseIMPACT CollaboratoryOutcome ascertainmentPoint of careNonpharmacological interventionsReal-world settingComplex interventionsTrialsIntervention effectivenessVulnerable populationsPragmatic designHealthcare systemNational InstituteClinical scientistsSuch interventionsInterventionDementiaPLWDDiseaseCaregiversResearch priorities