Epidemiology - Surveillance.
Diane Woolard Ph. D.
Upon completion of this seminar the students should be able to describe
- principles of disease surveillance in the community.
- the most prevalent conditions
- the role of a health agency in intervening to prevent or delay onset of, or provide early intervention to reduce, deteriorating health status of various population groups.
- Purposes of surveillance to detect onset of acute infectious disease
- The capability to estimate changes in in incidence and prevalence of chronic diseases.
Community Surveys, Passive & Active surveillance, Chronic Diseases, Environmental Hazards, Denominator data, Numerator data, Prevalence, Incidence, and examples of epidemiologic investigations.
Chronic non-infectious diseases are as amenable to epidemiologic evaluation and intervention as acute communicable disease. Both types of disease require use of surveillance.
Go to PowerPoint Presentation This is a long presentation, so look at the concepts and be prepared to look back at the slides when you get to the quiz for the week and you should have a little problem with them.
Optional additional Slide Show from The Public Health Supercourse System, and this PDF of CDCs approach to chronic disease surveillance which has become increasing;y important with the current epidemic of chronic disease.
look at CDC web pages on Surveillance, including the Public Health Surveillance and Informatics Program Office (look at the different surveillance programs), CDC description of Surveillance (active and passive, bottom of web page) and scan the Epidemiology and Analysis Program Office (PDF) to get a feel for the scope of its activities.
Introduction to Public Health, Schneider, 4th/5th Editions, Scan Chapter 4. Read the section on Surveillance systems in Chapter 8
Case Definition from the CDC Look at the history of the subject,then go to the search box on the left and click on 'Diseases and Conditions' and select infectious, and the year 2016 and get the list to see some of the definitions to get a feel for the scope. Click on one of two of the definitions to examine how the CDC has defined these conditions for all epidemiologists in the world to use. Note definitions have changed over time, and look at the changes for example Lyme disease.
In addition to case definitions we need the be concerned about causes of death. One of the attributes we look at in a community assessment is causes of death such as high blood pressure or stroke. However, many of these attributes on death certificates are the result of a best guess, because we rarely perform autopsies on people dying from "normal" deaths. We probably have a 99.9% counting of deaths in the United States but when we consider health around the world take a look at this paper from Science and consider how valid much of the international data may be. Think about the publicity surrounding Ebola and compare the number of deaths from Malaria to Ebola. Which should have a higher priority?
The Cochrane Library is being used increasingly by those interested in Surveillance. It is in many respects the Gold Standard for surveillance methods. It has started a Health Promotion and Public Health section which those of you, interested in the topic, may want to review. Be sure to click on each the tabs at the top of the page. Be sure to click on the about us tab and then click on the Review link and understand who makes up a Cochrane Review team.
Look at the USPSTF Introduction webpage And click on the guide to clinical preventive services, and look at the large number of recommendations made..
How about routine health screens? For years these have been the holy grail of primary care. Scan this paper on Breast Screening, then look at this recent viewpoint on Less Screening.
Review the functions of Epidemic Intelligence Service EIS, then the WHO's Department of Communicable Disease Surveillance and Responses.
Then review CDC's Behavioral Risk Factor Surveillance System (BRFSS) click on the 'prevalence and data and analysis tools' and each of the links on that page. Also look at the changes being put into place and consider whether the changes will make comparisons with prior surveys difficult (The blue box of information on the second page is the key to the article). One of the issues to discuss when considering surveillance is the tendency of those with a special interest in a disease to over focus on it and want to label everything by screening everyone. All this does is increase the number of false positives found on screening and result in unnecessary and often dangerous procedures when none are called for. See this recent paper from the BMJ.
The Disappearing Autopsy Why do you think I included this?
Screening for Breast Cancer. With all you hear about the NHS from posturing US politicians, what does this tell us about quality in the UK? Do you believe screening is overused in routine practice? What about screening for the elderly?