Biostatistics in Clinical Trials

Statistics is the science of collecting, summarizing, presenting and interpreting data, and of using them to estimate the magnitude of associations and test hypotheses. It has a central role in medical investigations. Not only does it provide a way of organizing information on a wider and more formal basis than relying on the exchange of anecdotes and personal experience, it takes into account the intrinsic variation inherent in most biological processes. For example, not only does blood pressure differ from person to person, but in the same person it also varies from day to day and from hour to hour. It is the interpretation of data in the presence of such variability that lies at the heart of statistics. Thus, in investigating morbidity associated with a particular stressful occupation, statistical methods would be needed to assess whether an observed average blood pressure above that of the general population could simply be due to chance variations or whether it represents a real indication of an occupational health risk