TY - CHAP M1 - Book, Section TI - Epidemiology of Structural Birth Defects and Preterm Birth A1 - Shaw, Gary M. A2 - Stevenson, David K. A2 - Cohen, Ronald S. A2 - Sunshine, Philip PY - 2015 T2 - Neonatology: Clinical Practice and Procedures AB - Epidemiology is the study of the distributions and the etiologic factors of diseases in human populations. Epidemiologists employ a variety of designs and statistical procedures to identify and assess potential etiologic factors. Unless a particular exposure (procedure) is beneficial, most studies cannot ethically be experimental in design, such as randomized clinical trials. Therefore, epidemiologists are typically relegated to conducting observational studies of populations. As a contrast, in experimental studies, the investigator has much more “control” over the many exposures study subjects may encounter, whereas in observational studies, the investigator is relegated to being an “observer” of the exposure of subjects in a study population. In some instances, such exposures may not be known or cannot be adequately controlled for. Thus, observational epidemiology studies provide us with associations and do not “establish” causation. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1109791069 ER -