A multi-center trial is a form of research or clinical trial which takes place at several locations simultaneously.
For example: in large-scale tests of the efficacy of a new drug to treat Alzheimer's disease, the researchers may collect data from patients at a number of facilities around the country. Use of data from several sources is usually considered advantageous because it reduces the risk that anomalous results from one location will affect the data.
If patients at one location show beneficial effects of the drug, this might mean the drug is effective -- or it might merely reflect some idiosyncracy about the patients themselves.
For example: the patients at this clinic might be disproportionately wealthy, or healthy, or of a certain racial background -- and this may make them more (or less) susceptible to Alzheimer's disease, independent of the new drug. However, if patients at many different locations all show the same effects of taking the drug, this is stronger evidence of the drug's effectiveness.
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain