title: Stopping a clinical trial very early based on unplanned interim analyses: a group sequential approach.
abstract: In the conduct of a clinical trial, unexpectedly high rates of toxicity may cause a researcher to want to terminate the trial early even though no formal stopping rule had been specified. The experience of one such clinical trial is used as an example of the ways in which group sequential methodology can be applied in deciding to stop the study, as well as in reporting the results of the clinical trial. This approach is then compared to a Bayesian analysis.
authors.affiliation: Arizona Cancer Center, University of Arizona, Tucson 85724, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Emerson
mesh_terms: D000931:Antidotes / Q000627:therapeutic use; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001699:Biometry; D002986:Clinical Trials as Topic / Q000379:methods*; D005472:Fluorouracil / Q000009:adverse effects*; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D002955:Leucovorin / Q000627:therapeutic use; D007970:Leukopenia / Q000139:chemically induced; D008433:Mathematics; D015233:Models, Statistical; D009059:Mouth Diseases / Q000139:chemically induced / Q000453:epidemiology / Q000517:prevention & control*; D009061:Mouth Mucosa; D009369:Neoplasms / Q000188:drug therapy*; D012107:Research Design
chemical_list: D000931:Antidotes; D000964:Antimetabolites, Antineoplastic; D016179:Granulocyte Colony-Stimulating Factor; D002955:Leucovorin; D005472:Fluorouracil