Epidemiology is the study and analysis of the distribution who, when, and where , patterns and determinants of health and disease conditions in defined populations. It is a cornerstone of public health , and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results including peer review and occasional systematic review. Epidemiology has helped develop methodology used in clinical research , public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of epidemiological study include disease causation, transmission , outbreak investigation, disease surveillance , environmental epidemiology , forensic epidemiology , occupational epidemiology , screening , biomonitoring , and comparisons of treatment effects such as in clinical trials.
Case study - definition of case study by The Free Dictionary
A case series also known as a clinical series is a type of medical research study that tracks subjects with a known exposure, such as patients who have received a similar treatment,  or examines their medical records for exposure and outcome. Case series may be consecutive  or non-consecutive ,  depending on whether all cases presenting to the reporting authors over a period were included, or only a selection. When information on more than three patients is included, the case series is considered to be a systematic investigation designed to contribute to generalizable knowledge i. Case series have a descriptive study design ; unlike studies that employ an analytic design e.
How to do a case study
A case study is an in-depth study of one person, group, or event. In a case study, nearly every aspect of the subject's life and history is analyzed to seek patterns and causes of behavior. Case studies can be used in a variety of fields including psychology, medicine, education, anthropology, political science, and social work.
The broader sense of acronym inclusive of terms pronounced as the individual letters such as " TNT " is sometimes criticized, but it is the term's original meaning  and is in common use. The word acronym is formed from the Greek roots acr- , meaning "height, summit, or tip" and -onym , meaning "name". Whereas an abbreviation may be any type of shortened form, such as words with the middle omitted for example, Rd for Road or Dr for Doctor or the end truncated as in Prof.