Epidemiologist

So, You Want to be an Epidemiologist?Everything You Ever Wanted to Know About

Epidemiology in 60 minutes or less.

Presented by: Carmine Jabri

What is Epidemiology?

• “Epidemiology is the study of patterns of disease and injury in human populations and the application of this study to the control of health problems. With its focus on disease causation and prevention, this field is a fundamental science of both preventive medicine and public health.”1

• 1. The University of Texas. (2008). Division of epidemilogy and disease control. Retrieved on November 22, 2008 from: http://www.sph.uth.tmc.edu/epi/

What are the Origins of the Field of Epidemiology?

• Hippocrates, the “father of medicine” suggested a relationship between the occurrence of disease and the physical environment.1

• John Snow, the “father of modern day epidemiology” used epidemiological methods to discover the origin of the London cholera epidemic of 1849.2

• Louis Pasteur – germ theory of disease1

• Robert Koch discovered the organism that causes cholera. 1,3

• 1. McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5th ed.). Sudbury, MA: Jones and Bartlett.

• 2. Schneider, MJ. (2006). Introduction to public health. (2nd ed.). Sudbury, MA: Jones and Bartlett.

• 3. Novick, L., Morrow, C., Mays, G. (2008). Public health administration: Principles for population-based management . Sudbury, MA: Jones and Bartlett.

What does an Epidemiologist do?

• Research epidemiologists conduct research in an effort to eradicate or control infectious diseases. Research epidemiologists work at colleges and universities, schools of public health, medical schools, and independent research firms. 1

• Clinical epidemiologists work primarily in consulting roles at hospitals, informing the medical staff of infectious outbreaks and providing containment solutions. 1

• 1. Bureau of Labor Statistics. (2008). Medical scientists. Occupational outlook handbook 2008-2009 edition.. Retrieved on November 21, 2008 from: http://www.bls.gov/oco/ocos008.htm

What does an Epidemiologist do? Continued…

• “Epidemiologic studies focus on identifying distribution, determinants, and frequency of disease within populations by using statistical analysis.” 1

• Epidemiologists are concerned with getting the numbers of cases, the numbers of deaths and the numbers of the total population to calculate various rates such as: natality rates, morbidity rates and mortality rates.2

• Other rates include: Incidence, Prevalence, Attack Rates, Crude and Age-Adjusted rates, specific rates, cause-specific mortality rate, case fatality rate, and proportionate mortality ratio.

• 1. The University of Texas. (2008). Division of epidemilogy and disease control. Retrieved on November 22, 2008 from: http://www.sph.uth.tmc.edu/epi/• 2. McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5th ed.). Sudbury, MA: Jones and Bartlett.

What does an Entry-Level Epidemiologist do?

• Responsible for conducting Epidemiological studies to investigate, identify and analyze incidence, prevalence, trends, and causes of injuries or communicable, chronic or environmentally induced diseases.1

• Develops intervention strategies, policies and procedures• Evaluates new and existing prevention and control programs

based on epidemiologic findings.1

• Communicates with healthcare providers; social service agencies; schools; federal, state and local officials; the media; and others concerning disease and injury investigation, prevention and control.1

• Reviews and evaluates surveillance systems.1

• Conducts field interviews1

• Prepares investigation reports, statistical analyses and summaries on completed epidemiologic studies and evaluations.1

• Participates in preparing grant applications, research reports and other public health documents.1

• 1. Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett

What does a Senior Epidemiologist Do?

• In addition to the work that an entry-level Epidemiologist may do, as senior-level Epidemiologist may:

• Conduct case-control, cohort and cross-sectional studies1

• Prepare formal written reports of findings, including a description of the methods used, the findings and the interpretation of the findings1

• Conduct disease outbreak investigations1

• Perform statistical analyses of health data: ANOVA, trend analysis, multiple logistic regression, survival analysis, etc.

• Collect surveillance information1

• Identify corrective actions to environmental conditions resulting in adverse health conditions1

• Coordinates local, state and federal health research programs1

• Serves as principal investigator on local, state and federal health research grants1

• Supervises the work of lower-level epidemiologists.1• 1. Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett

Epidemiologists are Especially Important for 4 of the 10 Essential Public Health Services

• Monitoring Health Status• Diagnosing and investigating health events and

threats in the community• Assessing the impact and quality of services• Researching innovative solutions to health

problems1

• 1. Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett.

Notifiable Diseases

• Notifiable diseases are infectious diseases that can become epidemic and for which health officials maintain weekly records.1

• Each state health department gives the CDC reports on the list of notifiable diseases.1

• In 2002, the CDC listed about 60 diseases as notifiable at the national level. A few examples are: AIDS, Anthrax, Botulism, Cholera, Diptheria, Hantavirus, Hepatitis, Measles, Lime disease, Mumps, Rabies, Rubella, Tetanus, Tuberculosis, Varicella, etc. 1

• NETS (National Electronic Telecommunications System) is the method for reporting notifiable disease to the CDC.1

• 1. McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5 th ed.). Sudbury, MA: Jones and Bartlett.

Study Designs

• Descriptive Studies: “seek to describe the extent of an outbreak in regard to person, time and place”(p.81).1

• Analytical Studies: “test hypotheses about relationships between health problems and possible risk factors” (p. 83).1

• Experimental Studies: “are carried out in order to identify the cause of a disease or to determine the effectiveness of a vaccine, therapeutic drug or surgical procedure” (p. 84). 1

• 1. McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5th ed.). Sudbury, MA: Jones and Bartlett.

Study Designs

• ECOLOGIC– “A study designed to assess

the correlation between exposure rates and disease rates among different groups or populations over the same time period” (p. 571).1

• CROSS-SECTIONAL– “A descriptive study, such as a

population survey, which is designed to estimate the prevalence of a disease or exposure” (p. 570).1

• CASE-CONTROL– “A study design that compares

individuals who have a disease with individuals who do not have the disease in order to examine differences in exposure or risk factors for the disease” (p. 568).1

• COHORT– “An analytic study that follows

a group of subjects who have received a specific exposure. The incidence of a specific disease or other outcome of interest is tracked over time. The incidence in the exposed group is compared to the incidence in groups that are non-exposed, have different levels of exposure or have different types of exposures” (p. 569).1

1. Friis, R., & Sellers, T. (2004). Epidemiology for public health practice. (3rd ed.). Sudbury, MA: Jones and Bartlett.

The Application of Epidemiology in the Real World: Then and Now

• Flu Pandemic of 1918-1919• Legionnaires’ Disease –

19761

• Eosinophilia-Myalgia Syndrome - 19891

• Bird Flu• Future outbreak of Pandemic

Influenza• HIV/AIDS and other STDs• Antibiotic resistance• Malaria• Guinea Worm• Chronic Diseases• Food Poisoning• Bioterrorism• 1. Schneider, MJ. (2006). Introduction to public health. (2nd

ed.). Sudbury, MA: Jones and Bartlett.

Examples

• Morbidity and Mortality Weekly Report (MMWR): is prepared by the CDC based on reports from state health departments and lists morbidity and mortality data by state and regions of the country, as well as outbreaks of disease, environmental hazards, unusual cases or other public health problems.1

• National Health Interview Survey (NHIS): National Center for Health Statistics asks people questions about their health.1

• National Health and Nutrition Examination Survey (NHANES): assesses the health and nutritional status of the U.S. population.1

• Behavioral Risk Factor Surveillance System (BRFSS): state-based telephone survey to ascertain the prevalence of high-risk behaviors such as smoking, excessive alcohol consumption, physical inactivity and lack of preventive health care.1

• Youth Risk Behavioral Surveillance System (YRBSS) monitors high-risk behaviors among youth and young adults such as: “behaviors that contribute to intentional and unintentional injuries, tobacco use, alcohol and drug use, sexual behaviors, unhealthy dietary behaviors and physical inactivity.”1

• 1. McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5 th ed.). Sudbury, MA: Jones and Bartlett.

Examples continued…

An example of a prospective cohort study is in 1950-1952, British Epidemiologists Richard Doll and A. Bradford Hill sent out a survey to all physicians in the UK asking whether they were smokers, past smokers or nonsmokers. Smokers and past smokers were asked for additional information and they received over 40,000 responses. They kept track of which doctors died and the cause of death and after only 4 years, found that the death rate of smokers was 20 times higher than that of nonsmokers and it increased as the amount of smoking increased. They tracked all of the doctors for 20 years until 1971 and the results confirmed their earlier observations. 1

1. Schneider, MJ. (2006). Introduction to public health. (2nd ed.). Sudbury, MA: Jones and Bartlett.

More Examples

• Recently, in Northeastern Oklahoma, there was large outbreak of a rare form of E. coli (E. coli 011), which was the largest outbreak in the U.S. of this type of E.coli.1

• The Oklahoma State Department of Health (2008) interviewed 1843 people and found that most of the people who became ill ate at Country Cottage from Aug. 15 through Aug. 23, 2008.2

• The incubation period for this type of E. coli is 2 to 10 days. It can be spread not only from food sources but by infected people who have diarrhea and don’t wash their hands well.3

• According to the Oklahoma State Department of Health (2008), “At least 314 persons became ill as a result of the outbreak. Of that number, 246 were adults, 65 were children, and the ages of three cases have not yet been identified. One person died. At least 72 persons have been hospitalized including 17 who have received dialysis treatment.”2

• 1. Fox News. (2008, September 3). E. coli outbreak in Okla. largest of its kind in U.S. history. Retrieved on 10/29/08 from: http://www.foxnews.com/story/0,2933,415643,00.html2. OSDH. (2008, September 16). Situation update no. 16: Outbreak of severe diarrheal illness in Northeastern Oklahoma. Retrieved on 10/29/08 from: http://www.ok.gov/health/Organization/Office_of_Communications/News_Releases/2008_News_Releases/Situation_Update_No_16_-_Outbreak_of_Severe_Diarrheal_Illness_in_Northeastern_Oklahoma.html

3. OSDH. (2008). Northeast Oklahoma E. coli outbreak advice for consumers. Retrieved on 10/29/08 from: http://www.ok.gov/health/Organization/Office_of_Communications/News_Releases/2008_News_Releases/Northeast_Oklahoma_E._coli_Outbreak_Advice_for_Consumers.html

The Future of Epidemiology

• MOLECULAR EPIDEMIOLOGY– “A field of epidemiology

that uses biomarkers (DNA, serum levels of micronutrients) to establish exposure-disease associations” (p. 576).1

• GENETIC EPIDEMIOLOGY– “The field of epidemiology

concerned with inherited factors that influence risk of disease” (p. 573).1

1. Friis, R., & Sellers, T. (2004). Epidemiology for public health practice. (3rd ed.). Sudbury, MA: Jones and Bartlett.

So You Want a Career in Epidemiology?

• What type of degree is needed to become and Epidemiologist?

• Epidemiologists typically need at least a master’s degree in public health, but some work requires a Ph.D. or medical degree. 1

• What is the Salary Range for an Epidemiologist?

• Median annual earnings of wage and salary epidemiologists were $56,670 in May 2006. The middle 50 percent earned between $45,220 and $71,080. The lowest 10 percent earned less than $36,920, and the highest 10 percent earned more than $87,300. 1

• Epidemiologists with PhD’s, MD’s, DVM’s, DDS’s or RN’s may be able to get 6-figure salaries.2

• 1. Bureau of Labor Statistics. (2008). Medical scientists. Occupational outlook handbook 2008-2009 edition.. Retrieved on November 21, 2008 from: http://www.bls.gov/oco/ocos008.htm

• 2. Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett.

Where can I work with a degree in Epidemiology?

• In 2006, “Among epidemiologists, 57 percent were employed in government; 12 percent were employed in hospitals; 11 percent were employed in colleges and universities; and 9 percent were employed in scientific research and development services.” 1

• 1. Bureau of Labor Statistics. (2008). Medical scientists. Occupational outlook handbook 2008-2009 edition.. Retrieved on November 21, 2008 from: http://www.bls.gov/oco/ocos008.htm

• Local and State Health Departments

• Hospitals• Pharmaceutical

Companies• DHHS – CDC, FDA, NIH,

etc.• The Central Intelligence

Agency• The World Health

Organization• The United Nations• Other organizations

What is the Job Outlook for Epidemiologists?

• “Employment growth should also occur as a result of the expected expansion in research related to illnesses such as AIDS, cancer, and avian influenza, along with growing treatment problems such as antibiotic resistance. Moreover, environmental conditions such as overcrowding and the increasing frequency of international travel will tend to spread existing diseases and give rise to new ones.” 1

• Additional Epidemiologists are needed especially in the area of: infectious disease, chronic disease and terrorism-related epidemiologists.2

• 1. Bureau of Labor Statistics. (2008). Medical scientists. Occupational outlook handbook 2008-2009 edition.. Retrieved on November 21, 2008 from: http://www.bls.gov/oco/ocos008.htm

• 2. Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett.

References

Bureau of Labor Statistics. (2008). Medical scientists. Occupational outlook handbook 2008-2009 edition.. Retrieved on November 21, 2008 from: http://www.bls.gov/oco/ocos008.htm

Friis, R., & Sellers, T. (2004). Epidemiology for public health practice. (3 rd ed.). Sudbury, MA: Jones and Bartlett.

Fox News. (2008, September 3). E. coli outbreak in Okla. largest of its kind in U.S. history. Retrieved on 10/29/08 from: http://www.foxnews.com/story/0,2933,415643,00.html

McKenzie, J., Pinger, R., & Kotecki, J. (2005). An introduction to community health. (5 th ed.). Sudbury, MA: Jones and Bartlett.

Novick, L., Morrow, C., Mays, G. (2008). Public health administration: Principles for population-based management . Sudbury, MA: Jones and Bartlett.

OSDH. (2008, September 16). Situation update no. 16: Outbreak of severe diarrheal illness in Northeastern Oklahoma. Retrieved on 10/29/08 from: http://www.ok.gov/health/Organization/Office_of_Communications/News_Releases/2008_News_Releases/Situation_Update_No_16_-_Outbreak_of_Severe_Diarrheal_Illness_in_Northeastern_Oklahoma.html

OSDH. (2008). Northeast Oklahoma E. coli outbreak advice for consumers. Retrieved on 10/29/08 from: http://www.ok.gov/health/Organization/Office_of_Communications/News_Releases/2008_News_Releases/Northeast_Oklahoma_E._coli_Outbreak_Advice_for_Consumers.html

Schneider, MJ. (2006). Introduction to public health. (2nd ed.). Sudbury, MA: Jones and Bartlett.The University of Texas. (2008). Division of epidemilogy and disease control. Retrieved on November 22,

2008 from: http://www.sph.uth.tmc.edu/epi/Turnock, B. (2006). Public health: Career choices that make a difference. Sudbury, MA: Jones and Bartlett.