{"doi":"10.17615/ge71-h757","title":"Flexible Analytical Methods for Adding a Treatment Arm Mid-Study to an Ongoing Clinical Trial","abstract":"It is not uncommon to have experimental drugs under different stages of development for a given disease area. Methods are proposed for use when another treatment arm is to be added mid-study to an ongoing clinical trial. Monte Carlo simulation was used to compare potential analytical approaches for pairwise comparisons through a difference in means in independent normal populations including 1.) a linear model adjusting for the design change (stage effect), 2.) pooling data across the stages, or 3.) the use of an adaptive combination test. In the presence of intra-stage correlation (or a non-ignorable fixed stage effect), simply pooling the data will result in a loss of power and will inflate the type I error rate. The linear model approach is more powerful, but the adaptive methods allow for flexibility (re-estimating sample size). The flexibility to add a treatment arm to an ongoing trial may result in cost savings as treatments that become ready for testing can be added to ongoing studies.","journal":"UNC Libraries","year":2020,"id":141532,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9573,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":607028,"name":"Yuko Y. Palesch","orcid":"0000-0003-3434-8550","position":1,"is_corresponding":false},{"id":405716,"name":"Jordan J. Elm","orcid":null,"position":2,"is_corresponding":false},{"id":283328,"name":"Bernard Ravina","orcid":null,"position":3,"is_corresponding":false},{"id":607029,"name":"Vanessa K. Hinson","orcid":"0009-0007-0677-1956","position":4,"is_corresponding":false},{"id":398232,"name":"Wenle Zhao","orcid":"0000-0003-0496-9700","position":5,"is_corresponding":false},{"id":35351,"name":"Gary G. Koch","orcid":null,"position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-18T23:17:24.429854Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}