TEST 2 - What is Epidemiology?

Eight pairs of small Oregon communities were assigned to receive either a school-based adolescent tobacco use prevention program or the school-based program plus a community program. In each of the next five years, seventh and ninth grade students in these communities were surveyed about tobacco and other substance use. Surveys during years two and five indicated that the prevalence of smoking was significantly lower in the community intervention communities. This example illustrates which one of the following uses of epidemiology in public health?

(-) Evaluation of intervention programs - Surveillance - Community health assessment - Screening - Targeting intervention programs - Disease outbreak investigation

Which is the host?

(A) Unimmunized children B) Pertussis bacteria (Bordatella pertussis) C) Crowded school room

A baby's heel is pricked to obtain a few drops of blood for laboratory testing for signs of phenylketonuria (PKU). Usually, the baby's blood specimen is sent to a state police health laboratory for testing, and findings are sent to the health care professional responsible for the infant's care. If there are abnormal laboratory results, the baby needs more extensive and precise testing to see if he or she does have PKU. This example illustrates which one of the following uses of epidemiology in public health?

- Community health assessment - Evaluation of intervention programs - Targeting intervention programs - Disease outbreak investigation (-) Screening - Surveillance

Cases in the Metropolitan Atlanta Congenital Defects Program are identified through ongoing active search and review of newborn and pediatric hospital records, and through birth certificates, death certificates, fetal death certificates, pathology reports, autopsy records, and records of cytogenetic laboratories. This program provides reports on rates of birth defects to local and state officials on a regular basis. This example illustrates which one of the following uses of epidemiology in public health?

- Disease outbreak investigation - Screening - Evaluation of intervention programs (-) Surveillance - Targeting intervention programs - Community health assessment

Using 2005 data, health district staff determined that the population in Kitsap County, Washington, has a median age of 37.2 years. Nine percent of residents live in poverty, 4.2 percent on unemployed, and 12 percent have no health insurance. The teen birth rate is 9/1000, and the infant mortality rate is 6.2/1000. This example illustrates which one of the following uses of epidemiology in public health?

- Evaluation of intervention programs - Disease outbreak investigation - Surveillance - Screening - Targeting intervention programs (-) Community health assessment

Between April 30 and May 17, as part of routine surveillance, 32 cases of hepatitis were reported to the district health department in Ogemaw County, Michigan (an unusually high number in this county for such a short time period). The health department determined that the illness was most common among boys 15 - 19 years old (16 cases) and boys 10 - 14 years old (12 cases). Additionally, more than 90 percent of the ill people had recently eaten at West Branch Bakery. health department personnel determined that consumption of glazed donuts at the bakery exposed residents to hepatitis. This example illustrates which one of the following uses of epidemiology in public health?

- Screening (-) Disease outbreak investigation - Evaluation of intervention programs - Targeting intervention programs - Community health assessment

In an effort to prevent child abuse and neglect, new mothers were enrolled in a support program shortly after delivery if they had any of the following factors that indicated they may be at high risk for this problem: single parenthood, ambivalence to the pregnancy (sough termination, no prenatal care), and personal experience of physical domestic violence or childhood abuse. Participants received home visits by the program's staff for the first 12 months of an infant's life, with extensive program services offered and implemented according to the individual mother's needs. This example illustrates which one of the following uses of epidemiology in public health?

- Screening - Surveillance - Disease outbreak investigation (-) Targeting intervention programs - Evaluation of intervention programs - Community health assessment

Public Health Program Evaluation

Systematic way to collect information about the characteristics, activities, and results of a program in order to make decisions about the program Purpose of public health program evaluation: - Accountability to public and others - Communication about what you do - Documentation of program's progress - Measurement of program's results

Intervention Programs

Targeted interventions: - Public health actions aimed at groups with higher risk, with the goal of improving specific health outcomes - Choice of target group based on assessment of condition (What is the distribution within the specific population? What are the determinants? What interventions can affect the determinants?) Interventions targeted to make best use of resources for greatest impact: - SIDS prevention might target: groups at high risk AND older women who have other children

Epidemiology is the study of...

The distribution (person, place, time - descriptive epidemiology) and determinants (agent, host, environment - analytic epidemiology) of disease (and health events and health) in human populations - and the application of this study to the control of health problems.

Screening

The examination of asymptomatic people in order to classify them as likely, or unlikely, to have the disease that is the object of screening (not same as diagnosis) Screening is used when: - The disease is an important public health problem - There is an asymptomatic stage of the disease - Treatment is more effective if initiated early - A suitable screening test is available Epidemiologists measure: - The accuracy of screening tests

Rates are often used by epidemiologists to:

describe the disease burden and compare populations

Epidemiology focuses on:

describing and determining risk in entire populations rather than in individual patients

Epidemiology is the study of:

distribution and determinants of disease, health, and health events

In public health practice, the tools of epidemiology are used:

in a variety of situations, including surveillance, outbreak investigation, screening, community health assessment, and program planning and evaluation

Uses of Epidemiology in Public Health Practice

Surveillance Disease investigation Community health assessment Screening Targeting intervention programs Evaluation of intervention programs

Epidemiological Concepts and Principles

Events and diseases are not randomly distributed in a population. Determinants of events can be identified. Determinants are studied for entire populations. Prevention and control in the population are the main focus, rather than diagnosis and treatment of a single patient. Epidemiology uses rates to study populations and develop prevention and control programs.

Disease Investigation

Goals of a disease outbreak investigation: - Identify the source of illness - Guide public health intervention Outbreak recognition mechanisms: - Routine surveillance activities - Reports from clinicians, laboratories, individuals Outbreak investigation methods: - Descriptive epidemiology - Analytic epidemiology

What do we mean by distribution?

How many persons are affected (that is, burden of disease)? Who is affected - what are their characteristics? Where are the affected persons? When is the disease most common? Is the distribution changing?

Specificity with Mammograms

If breast cancer is not present, what is the likelihood that the mammogram will be negative?

Sensitivity with Mammograms

If breast cancer is present, what is the likelihood that the mammogram will be positive?

Which is the agent?

A) Unimmunized children (B) Pertussis bacteria (Bordatella pertussis) C) Crowded school room

Which is the environment?

A) Unimmunized children B) Pertussis bacteria (Bordatella pertussis) (C) Crowded school room

Which of the following questions would be least likely to be asked in epidemiology?

A) Where in the US is tuberculosis most common? B) Is tuberculosis more common in the US in some times of the year than others? (C) What treatment should this patient be given? D) Which population groups in the US are most likely to become ill with tuberculosis?

What do we mean by determinants?

Agent characteristics: - Infectious agents - Non-infectious agents Host characteristics: - Constitutional or genetic factors - Behaviors, habits, lifestyles Environmental characteristics: - Residential and occupational exposures - Socio-political factors

SIDS: Potential Determinants of Risk

Infectious Agent Characteristics: - Respiratory infection - Agents against diarrhea, vomiting Host Constitutional or Genetic Factors: - Male infant - Multiple gestation (twins or triplets) - Low birthweight Host Behaviors, Habits, and Lifestyles: - Bottle-feeding - Infant put to sleep on stomach or side

Epidemiologists believe that events are:

NOT random, and observed patterns can inform judgments about determinants.

Community Health Assessment

One of the three core public health functions: - Assurance, policy development, assessment Systematic process that periodically provides pertinent information to assess the health of a community - Who are we? - How healthy are we? - How healthy are our lifestyles and behaviors? - How healthy is our environment? Relies on local and regional knowledge to be effective Creates products for public and policy makers

Public Health Surveillance

Ongoing, systematic - Collection (collecting health information routinely) - Analysis (analyzing that information routinely) - Interpretation - Dissemination of data (communicating conclusions to the public) About a health-related event for use in public health action to reduce morbidity (illness) and mortality (death) and to improve health.

Types of Surveillance

Passive surveillance Active surveillance Local Health Dpt. - lab, hospital State - physician