Biomaterial Database

The scientific basis of clinical trials: statistical aspects. 1997

E A Gehan

Lombardi Cancer Center, Georgetown University Medical Center, Washington, DC 20007, USA.

The objective of this paper is to delineate some of the advances in clinical oncology that have occurred since the 1950s in the context of methodological principles established by Dr. Emil J Freireich and colleagues. Four statistical aspects of the methodological developments in clinical trials are considered and illustrated by real examples: a quantitative approach to the design and analysis of clinical trials; the randomized controlled trial; the nonrandomized controlled trial; and the use of regression models in clinical studies.

UI	MeSH Term	Description	Entries
D007938	Leukemia	A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemias were originally termed acute or chronic based on life expectancy but now are classified according to cellular maturity. Acute leukemias consist of predominately immature cells; chronic leukemias are composed of more mature cells. (From The Merck Manual, 2006)	Leucocythaemia,Leucocythemia,Leucocythaemias,Leucocythemias,Leukemias
D009369	Neoplasms	New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.	Benign Neoplasm,Cancer,Malignant Neoplasm,Tumor,Tumors,Benign Neoplasms,Malignancy,Malignant Neoplasms,Neoplasia,Neoplasm,Neoplasms, Benign,Cancers,Malignancies,Neoplasias,Neoplasm, Benign,Neoplasm, Malignant,Neoplasms, Malignant
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D012107	Research Design	A plan for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that an hypothesis can be tested properly.	Experimental Design,Data Adjustment,Data Reporting,Design, Experimental,Designs, Experimental,Error Sources,Experimental Designs,Matched Groups,Methodology, Research,Problem Formulation,Research Methodology,Research Proposal,Research Strategy,Research Technics,Research Techniques,Scoring Methods,Adjustment, Data,Adjustments, Data,Data Adjustments,Design, Research,Designs, Research,Error Source,Formulation, Problem,Formulations, Problem,Group, Matched,Groups, Matched,Matched Group,Method, Scoring,Methods, Scoring,Problem Formulations,Proposal, Research,Proposals, Research,Reporting, Data,Research Designs,Research Proposals,Research Strategies,Research Technic,Research Technique,Scoring Method,Source, Error,Sources, Error,Strategies, Research,Strategy, Research,Technic, Research,Technics, Research,Technique, Research,Techniques, Research
D002985	Clinical Protocols	Precise and detailed plans for the study of a medical or biomedical problem and/or plans for a regimen of therapy.	Protocols, Clinical,Research Protocols, Clinical,Treatment Protocols,Clinical Protocol,Clinical Research Protocol,Clinical Research Protocols,Protocol, Clinical,Protocol, Clinical Research,Protocols, Clinical Research,Protocols, Treatment,Research Protocol, Clinical,Treatment Protocol
D002986	Clinical Trials as Topic	Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.	Clinical Trial as Topic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000971	Antineoplastic Combined Chemotherapy Protocols	The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.	Anticancer Drug Combinations,Antineoplastic Agents, Combined,Antineoplastic Chemotherapy Protocols,Antineoplastic Drug Combinations,Cancer Chemotherapy Protocols,Chemotherapy Protocols, Antineoplastic,Drug Combinations, Antineoplastic,Antineoplastic Combined Chemotherapy Regimens,Combined Antineoplastic Agents,Agent, Combined Antineoplastic,Agents, Combined Antineoplastic,Anticancer Drug Combination,Antineoplastic Agent, Combined,Antineoplastic Chemotherapy Protocol,Antineoplastic Drug Combination,Cancer Chemotherapy Protocol,Chemotherapy Protocol, Antineoplastic,Chemotherapy Protocol, Cancer,Chemotherapy Protocols, Cancer,Combinations, Antineoplastic Drug,Combined Antineoplastic Agent,Drug Combination, Anticancer,Drug Combination, Antineoplastic,Drug Combinations, Anticancer,Protocol, Antineoplastic Chemotherapy,Protocol, Cancer Chemotherapy,Protocols, Antineoplastic Chemotherapy,Protocols, Cancer Chemotherapy
D016019	Survival Analysis	A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.	Analysis, Survival,Analyses, Survival,Survival Analyses
D016032	Randomized Controlled Trials as Topic	Works about clinical trials that involve at least one test treatment and one control treatment, concurrent enrollment and follow-up of the test- and control-treated groups, and in which the treatments to be administered are selected by a random process, such as the use of a random-numbers table.	Clinical Trials, Randomized,Controlled Clinical Trials, Randomized,Trials, Randomized Clinical