Several researchers from developing countries are not knowledgeable in Epidemiology and Research Methodology. It will result in a poorly conducted trial. Several important research questions are proved in wrong study designs and analysis.
Nowadays, EDX is a pilot program of Harvard University, MIT and Berkerly to explore online education.
We have just finished an excellent course of Biostatistics and Epidemiology directed by Marcello Pagano and Francis Cook (Harvard University).
You can register for free and get another course, wait until this beautiful course (Health in Numbers) is available again, or in two more days will begin a course in Basic Statistic of Berkerley.
search also for Basic Epidemiology By R. Beaglehole, R. Bonita, and T. Kjelstrom on the net - it is not only an excellent introductory text book, but also freely available from the WHO website for download!