What Do You Understand by Term Epidemiology free essay sample

What do you understand by term Epidemiology? How the study of Epidemiology helps us to know the health status of the community? Discuss the importance of Surveillance in the community health. Epidemiology is the study of how often diseases occur in different groups of people and why. Epidemiological information is used to plan and evaluate strategies to prevent illness and as a guide to the management of patients in whom disease has already developed. Like the clinical findings and pathology, the epidemiology of a disease is an integral part of its basic description. The subject has its special techniques of data collection and interpretation, and its necessary jargon for technical terms. This short book aims to provide an ABC of the epidemiological approach, its terminology, and its methods. Our only assumption will be that readers already believe that epidemiological questions are worth answering. This introduction will indicate some of the distinctive characteristics of the epidemiological approach. The distribution of disease occurs in patterns in a community. In epidemiology we study these distribution patterns in various subgroups of the population by time, place and person; that is: A. Whether there is an increase or decrease of disease over time; whether there is a higher concentration of disease in one geographic area than in others B. Whether the disease occurs more often in Men or in a particular age-group, and characteristic of those affected and not affected. Study of these patterns may suggest or lead to measure to control or prevention of disease. Also one can formulate an etiological hypothesis of disease through these â€Å"descriptive epidemiology†. Study of Epidemiology helps us in measuring the spread of disease, affected persons, how to prevent the disease from spreading. The following are the studies of Epidemiology: (A)Observational studies: Descriptive Studies 1)Case reports 2)Case series 3)Ecological/Correlation 4)Cross-Sectional/ prevalence Analytical Studies (1)Case control/Case reference (2)Cohort/ Follow-up (B)Experimental Studies/Intervention Studies (1)Randomized controlled trials/Clinical trials (2)Field trials/Community intervention trials (3)Community trials Descriptive Studies: Epidemiological investigations often start with eth case reports and evolve to become a series of cases. The procedure involved in descriptive studies are defining population and the disease under study, describing the disease by time, place and person, measuring the disease (in terms of incidence/prevalence) comparing with known indices and formulating an etiological hypothesis. Descriptive epidemiology may use a cross-sectional or longitudinal design to obtain estimates of the cross section of the population at one point in time. In longitudinal study examinations are repeated in the same population over a prolonged period of time by means of follow-up examination. Analytical Studies: Here the objective is not to formulate, but to test hypotheses. In contrast to descriptive studies that look at entire populations, in analytical studies, the subject of interest is the individual within the population. Here the comparison is made between cause/study group and control groups. Analytical studies may be observational or experimental. Observational Studies: In an Observational study, the epidemiologist assigns subjects to case and comparison groups. This assignment may take place after an event has occurred or before an event has happened. Observational studies are carried out to determine whether or not the statistical association exits between a disease and a suspected cause, and if one exists the strength of association. Cohort study: The starting point of a cohort study is the recording of healthy subjects with and without exposure to the putative agent or the characteristic being studied. Individuals exposed to the agent under study (index subjects) are followed over time and their health status is observed and recorded during the course of the study. In order to compare the occurrence of disease in exposed subjects with its occurrence in non-exposed subjects, the health status of a group of individuals not exposed to the agent under study (control subjects) is followed in the same way as that of the group of index subjects. Case-control study: The starting point of a case-control study is subjects with the disease or condition under study (cases). The cases’ history of exposure or other characteristics, or both, prior to onset of the disease, is recorded through interview and sometimes by means of records and other sources. A comparison group consisting of individuals without the disease under study (controls) are assembled, and their past history is recorded in the same way as for the cases. The purpose of the control group is to provide an estimate of the frequency and amount of exposure in subjects in the population without the disease being studied. Whereas the cohort study is concerned with frequency of disease in exposed and non-exposed individuals, the case-control study is concerned with the frequency and amount of exposure in subjects with a specific disease (cases) and people without the disease (controls). Experimental studies: Here is the subject are observed under predetermined conditions. They involve some action, intervention or manipulation or withdrawal of the suspected cause in the experimental group while making no change in the control group. They provide â€Å"Scientific proof† of etiological factor. Randomized clinical trials are the best examples of experimental studies. Surveillance: It is defined as â€Å"the continuous scrutiny of the factor that determines the occurrence and distribution of disease and other conditions of ill health†. The main objectives of surveillance are: (a)To provide information about new and changing trends in the health status of a population. E. g. morbidity, mortality, nutritional status etc. (b)To provide feed-back for modifying the policy and system itself if needed. (c)To provide timely warning of public health disaster so that interventions can be mobilized. Sentinel Surveillance: No routine notification system can identify all cases of infection or disease. A method for identifying the missing cases and thereby supplementing the notified cases is required. This is known as â€Å"sentinel surveillance†. Surveillance is important in the community health which helps: (1)To study the episodes and trends of disease with a view to prevent and control. (2)Improve surveillance and reporting of notified infectious disease. (3)Increase awareness by the general population and medical practioners and related professions of functions of functions of unit. (4)Create methods to encourage early notification of infectious disease. Provides the bases for epidemiological studies and research. (5)Control and prevent the occurrence of communicable disease.