Role of Epidemiology in Public Health

 Epidemiology

                                       "Epidemiology is the study and analysis of the distribution, patterns and determinants of health and disease conditions in a defined population".

Epidemiologists

                                     "A person who studies or is an expert in the branch of medicine which deals with the incidence, distribution, and possible control of diseases".

Distribution

                              Epidemiology is concerned with the frequency and pattern of health events in a population.

Frequency 

                Frequency refers not only to the number of health events such as the number of cases of meningitis or diabetes in a population, but also to the relationship of that number to the size of the population. 

Pattern   

              Pattern refers to the occurrence of health-related events by time, place, and person. time patterns may be annual, seasonal, weekly, daily, hourly, weekday versus weekend, or any other breakdown of time that may influence disease or injury occurrence.

Role of Epidemiology in Public Health

                         

Functions

              In the mid-1980, five major tasks of epidemiology in public health practice were identified; 

Public Health surveillance 

                                       Public Health surveillance is the ongoing, systematic collection, analysis, interpretation, and dissemination of health data to help guide public health decision making and action. Surveillance is equivalent to monitoring the pulse of the community.

Field Investigation 

                           One of the first actions that results from a surveillance case report or report of cluster is investigation by the public health department. The investigation may be as limited as a phone call to the health-care provider to confirm or clarify the circumstances of the reported case, or it may involve a field investigation requiring the coordinated efforts of dozens of people to characterize the extent of an epidemic and to identify its cause.

Analytic Studies 

                        The hallmark of an analytic epidemiologic study is the use of valid comparison group. Epidemiologists must be skilled in all aspects of such studies, including design, conduct, analysis, interpretation, and communication of findings.

• Design includes determining the appropriate research strategy and study design, writing justifications and protocols, calculating sample sizes, deciding on criteria for subject selection, choosing an appropriate comparison group, and designing questionnaires.
• Conduct involves securing appropriate clearances and approvals, adhering to appropriate ethical principles, abstracting records, tracking down and interviewing subjects, collecting and handling specimens, and managing the idea.
• Analysis begins with describing the characteristics of the subjects. It progresses to calculation of rates, creation of comparative tables, and computation of measure of association, tests of significance, confidence intervals, and the like.
• Finally, interpretation involves putting the study findings into perspective, identifying the key take-home messages, and making sound recommendations. Doing so requires that the epidemiologist be knowledgeable about the subject matter and the strengths and weaknesses of the study.

 Evaluation

                 Evaluation is the process of determining as systematically and objectively as possible, the relevance, effectiveness, efficiency, and impact of activities with respect to established goals.

• Effectiveness refers to the ability of a program to produce the intended or expected results in the field; effectiveness differs from efficacy, which is the ability to produce results under ideal conditions.
• Efficiency refers to the ability of the program to produce the intended results with a minimum expenditure of  time and resources.

Linkages

             Other team members may be laboratorians, sanitarians, infection control personnel, nurses or other clinical staff, and increasingly, computer information specialists. Many outbreaks cross geographical and jurisdictional lines, so co-investigators may be from local,state, or federal levels of government, academic institutions, clinical facilities, or the private sector.

Policy Development

                               Indeed, epidemiologists who understand a problem and the population in which it occurs are often in a uniquely qualified position to recommended appropriate interventions. As a result,epidemiologists working in public health regularly provide input, testimony, and recommendations regarding disease control strategies, re-portable disease regulations, and health-care policy.