An epidemiological study is a research method used to understand the pattern, cause, and effect of diseases in a population. Some synonyms for epidemiological study include health study, population health study, disease surveillance, and epidemiology investigation. A health study may involve analyzing the incidence, frequency, and risk factors associated with a particular disease or health condition in a population or group. Disease surveillance refers to the systematic collection and analysis of health data to assess the prevalence and incidence of specific diseases in a population. Epidemiology investigation is a broader term used to describe the scientific process of studying the distribution and determinants of health and disease in populations to identify and control health problems.