Epidemiology studies refer to the study of the rate of occurrence of diseases in different groups of people and to study their reason for the occurrence (Centers for Disease Control and Prevention, 2012). This helps to evaluate the intensity of the situation and planning the strategies accordingly to prevent the disease to spread further and also manage the patients in which the disease is currently prevailing at times. According to a publication by Nature, (2018); the purposes of epidemiology studies play a major role in three cases, which are;
The epidemiology studies can be beneficial for the following purposes;
- Study the history of the course of the particular disease.
- Determine the frequency of the disease occurrence in a population.
- To identify the geographical patterns of disease occurrence.
- Identify the potential risk factors of the disease occurrence.
- Evaluate the effectiveness of the preventive and treatment programs implemented for the disease.
- Control or prevent the disease for the preservation of public health.
Disease management is one of the most important purposes of epidemiology studies. It is the assessment process that includes the steps like the collection of data, analysis, interpretation, and dissemination that is used for the disease management by devising prevention and health programs (Remington, Simoes, Brownson, & Siegel, 2003). Epidemiology works on three steps mainly for disease management purposes;
- It first defines the nature of the problem and its extent of the burden of the disease.
- Then, the programs to control the disease are found out by assessing the quality of the evidence of program effectiveness.
- Then the evaluation of these intervention programs is done by monitoring the trends in program outcomes over time.
The design of an epidemiological framework for disease management function is around the mechanism for identifying epidemic regions and trying to deploy methods to reduce the risk of the disease (Gilligan, 2002). Therefore, an understanding of the process that controls the invasion and persistence of the disease is important to devise methods for disease management.
The data collection methods for disease management comprise of cohort studies, case studies, and existing records. Data analysis methods mainly include trend based analyses and frequency analyses.
This helps in understanding the interactions and impact of vaccines on the epidemiology of vaccine-preventable disease (Lahariya, 2016). A vaccine is developed against the vaccine-preventable disease by understanding:
- the geographical pattern of the disease,
- variable factors impacting the disease like the rural-urban population,
- gender variation and,
- finding out the connection between disease burden and immunization coverage.
The basic concepts of vaccine development through epidemiology addresses the following purposes;
- The intensity of the disease outbreak or control.
- Vaccine efficacy and effectiveness.
- Failure of vaccines.
- Herd immunity and effect i.e. immunity developed in non-immunized individuals by coming in contact with the immunized individual.
- Epidemiological shift and disease modelling accordingly.
- Application of knowledge at a program level.
Understanding of vaccine development by epidemiology helps key stakeholders of policymaking, immunization program managers, public health experts, paediatricians, family physicians, and other experts or individuals. Therefore, the informed decision making will occur that will eventually lead to improvement in the vaccination coverage. Thus, vaccine epidemiology has a significant role in extending the advantages of vaccines to the additional population and the selected target group (Petrie & Gordon, 2018).
Cohort and control type of epidemiology studies helps in data collection for vaccine development. Molecular analyses, clinical analyses, meta-analysis, and other related statistical analyses get used in vaccine development.
Government policy making
Purposes of epidemiology include helping the government in policy making. The results from the epidemiological studies are very helpful in the development of public health policies. As the epidemiological studies provide a deep insight about the extent of the disease and help the government to understand the situation of the disease outbreak, it can prove to be very helpful in giving the interventions for the disease management that eventually helps the government in the formation of public health policies.
Field studies, data from national programmes, cohort, and control studies help in data collection for policy making. Analyses for policy making include time series and frequency analyses, inferential analyses (regression, t-tests, and others), meta-analyses, and forecasting analyses.
Epidemiology is responsible for extracting knowledge about the rate of occurrence of the disease and its extent that can be used in the development of policies for the prevention and control of the health problems. There are four levels at which the policies are designed based on a conceptual framework (Solar & Irwin, 2010);
- Aimed at making changes at a global level.
- Policies aimed at modifying social stratification by acting on the macro-social scale.
- Reducing the vulnerability and risk of exposure to a disease at intermediate levels.
- Policies for the reduction in harmful consequences of disease at the micro level i.e. individual interaction.
The need for epidemiology studies
Although the major need of an epidemiology study is to help in disease control, vaccine development and preparation of healthcare policy, there are other roles too. Epidemiology helps to study the course or natural history of a disease and to determine the frequency of disease in populations. Furthermore, they are also responsible to identify the patterns of disease occurrence and the factors responsible. This leads to the evaluation of the effectiveness of preventative and treatment measures. Thus, the ultimate goal of epidemiology is to apply disease based knowledge to their control through prevention and treatment, resulting in the preservation of public health.
- Centers for Disease Control and Prevention. (2012). Principles of epidemiology in public health practice : an introduction to applied epidemiology and biostatistics. Washington D.C.: Office of Workforce and Career Development. Retrieved from http://www.cdc.gov/ophss/csels/dsepd/SS1978/SS1978.pdf.
- Gilligan, C. A. B. T.-A. in B. R. (2002). An epidemiological framework for disease management (Vol. 38, pp. 1–64). Academic Press. http://doi.org/https://doi.org/10.1016/S0065-2296(02)38027-3.
- Lahariya, C. (2016). Vaccine epidemiology: A review. Journal of Family Medicine and Primary Care, 5(1), 7–15. http://doi.org/10.4103/2249-4863.184616.
- Nature. (2018). Epidemiology is a science of high importance. Nature Communications, 9(1). http://doi.org/10.1038/s41467-018-04243-3.
- Petrie, J. G., & Gordon, A. (2018). Epidemiological Studies to Support the Development of Next Generation Influenza Vaccines. Vaccines, 6(2), 17. http://doi.org/10.3390/vaccines6020017.
- Remington, P. L., Simoes, E., Brownson, R. C., & Siegel, P. Z. (2003). The Role of Epidemiology in Chronic Disease Prevention and Health Promotion Programs, 9(4), 258–265.
- Solar, O., & Irwin, A. (2010). A Conceptual Framework for Action on the Social Determinants of Health. Social Determinants of Health Discussion Paper 2 (Policy and Practice), 79. http://www.who.int/sdhconference/resources/ConceptualframeworkforactiononSDH_eng.pdf.