2 (Epidemiology) PRELIM PUBLIC HEALTH
67 Questions
11 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the meaning epidemiology?

Epi (upon) demos (people)

study of the distribution and determinants of health related states or events in specified populations, and the application of this study to the control of health problems

Epidemiology

method of causal reasoning based on developing and testing hypotheses grounded in such scientific fields as biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events

Epidemiology

Enumerate the Epidemiologic functions

<p>• Public health surveillance • field investigation • analytic studies • Evaluation • linkages</p> Signup and view all the answers

what is the purpose of public health surveillance

<p>information for action</p> Signup and view all the answers

the ongoing, systematic collection, analysis, interpretation, and dissemination of health data to help guide public health decision making and action

<p>Public health surveillance</p> Signup and view all the answers

require the coordinated efforts of dozens of people to characterize the extent of an epidemic and to identify its cause

<p>Field investigation</p> Signup and view all the answers

Field investigation is also known as

<p>shoe leather epidemiology</p> Signup and view all the answers

Often the methods are used in combination — with surveillance and field investigations providing clues or hypotheses about causes and modes of transmission, and analytic studies evaluating the credibility of those hypotheses.

<p>Analytic studies</p> Signup and view all the answers

s determining the appropriate research strategy and study design, writing justifications and protocols, calculating sample sizes, deciding on criteria for subject selection

<p>Design</p> Signup and view all the answers

nvolves securing appropriate clearances and approvals

<p>Conduct</p> Signup and view all the answers

describing the characteristics of the subjects.

<p>Analysis</p> Signup and view all the answers

the process of determining, as systematically and objectively as possible, the relevance, effectiveness, efficiency, and impact of activities with respect to established goal

<p>Evaluation</p> Signup and view all the answers

to the ability of a program to produce the intended or expected results in the field

<p>Effectiveness</p> Signup and view all the answers

o the ability of the program to produce the intended results with a minimum expenditure of time and resources.

<p>Efficiency</p> Signup and view all the answers

an investigation an epidemiologist usually participates as either a member or the leader of a multidisciplinary team

<p>Linkages</p> Signup and view all the answers

characterizes the amount and distribution of disease within and across populations.

<p>Descriptive epidemiology</p> Signup and view all the answers

common variables involve in Descriptive epidemiology

<p>person, place and time</p> Signup and view all the answers

5 W’s of descriptive epidemiology

<p>What, Who, When, Where, Why/How</p> Signup and view all the answers

refers to the study of the determinants of health- related outcomes

<p>Analytic epidemiology</p> Signup and view all the answers

Anticipated direction of effect is specified

<p>One sided</p> Signup and view all the answers

No direction is specified

<p>Two sided</p> Signup and view all the answers

Frequently used to evaluate research hypothesis

<p>Measures of effect</p> Signup and view all the answers

3 characteristics of Measures of effect

<p>Risk Ratio Rate ratio Odds ratio</p> Signup and view all the answers

Compares the incidence rate (IR)among the exposed the with the incidence rate among the non-exposed (IRE/IRNE)

<p>Rate ratio</p> Signup and view all the answers

Compares the incidence (I) proportion (risk) among exposed (E) with the incidence proportion (risk) among the non-exposed (NE) by the means of a ratio (IE/INE)

<p>Risk ratio</p> Signup and view all the answers

Compares the odds of exposure among those with the health outcome of interest to the odds of exposure among those without the health outcome

<p>Odds ratio</p> Signup and view all the answers

3 characteristics of evaluating associations

<p>• Chance • Bias • Confounding</p> Signup and view all the answers

Refers to likelihood of observing an apparent exposure/health outcome relationship, when in fact, one does not truly exist

<p>Chance</p> Signup and view all the answers

Refers to systematic error in the conduct of study

<p>Bias</p> Signup and view all the answers

state the Errors due to bias that can occur

<p>• The design of the study • The execution of the study • The analysis and interpretation of the study</p> Signup and view all the answers

7 part of BIAS

<p>• Selection bias • Referral bias • Information bias • Recall bias • Interviewer bias • Reporting bias • Temporal-precedence bias</p> Signup and view all the answers

Occurs when dissimilar procedures are used to select study subjects, and such procedures relate to the exposure or health outcome under study

<p>Selection bias</p> Signup and view all the answers

Occurs when subjects are differentially referred into a study based on knowledge of their exposure status

<p>Referral bias</p> Signup and view all the answers

Refers to different types of errors to the manner in which information is collected

<p>Information bias</p> Signup and view all the answers

outcome misclassification differs among persons exposed or not exposed, or similarly, exposure misclassification differs among case subjects and control subjects

<p>Differential</p> Signup and view all the answers

magnitude is unrelated to exposure or outcome status

<p>Non-differential</p> Signup and view all the answers

Occurs when subjects in the study groups formed recall of their exposure or outcome history differently

<p>Recall bias</p> Signup and view all the answers

Occurs when individuals involved in the collection of exposure or outcome data probe for or record information in a differential manner

<p>Interviewer bias</p> Signup and view all the answers

Refers to selective suppression or revealing of information, including sensitive information and information related to attitudes, beliefs, and perceptions

<p>Reporting bias</p> Signup and view all the answers

Can occur when subjects over-report exposure information in an attempt to show that a specific health condition experienced is not their fault

<p>Wish bias</p> Signup and view all the answers

Refers to incorrect classification of the presence of an exposure that occurs after the onset of the health outcome under study, rather than before it

<p>Temporal precedence bias</p> Signup and view all the answers

Frequently occurs in nonrandomized (observational) studies

<p>Confounding by indication</p> Signup and view all the answers

Nuisance effect that distorts the study results

<p>Confounding</p> Signup and view all the answers

2 categories of epidemiological studies:

<p>Experimental Observational</p> Signup and view all the answers

r determines through a controlled process the exposure for each individual (clinical trial) or community (community trial), and then tracks the individuals or communities over time to detect the effects of the exposure.

<p>Experimental</p> Signup and view all the answers

the epidemiologist simply observes the exposure and disease status of each study participant

<p>Observational</p> Signup and view all the answers

• the investigator observes rather than determines the participants’ exposure status.

<p>Cohort study</p> Signup and view all the answers

investigators start by enrolling a group of people with disease (at CDC such persons are called case-patients rather than cases, because case refers to occurrence of disease, not a person)

<p>Case control</p> Signup and view all the answers

• a sample of persons from a population is enrolled and their exposures and health outcomes are measured simultaneously.

<p>Cross-sectional studies</p> Signup and view all the answers

originally referred to an infectious microorganism or pathogen: a virus, bacterium, parasite, or other microbe.

<p>Agent</p> Signup and view all the answers

refers to the human who can get the disease.

<p>Host</p> Signup and view all the answers

refers to extrinsic factors that affect the agent and the opportunity for exposure.

<p>Environment</p> Signup and view all the answers

was proposed by Rothman in 1976, and has come to be known as what

<p>the Causal Pies</p> Signup and view all the answers

what are the chains of infection

<p>• Reservoir • Portals of exit • Modes of transmission • Portal of entry • Host</p> Signup and view all the answers

the habitat in which the agent normally lives, grows, and multiplies.

<p>Reservoir</p> Signup and view all the answers

is the path by which a pathogen leaves its host. The portal of exit usually corresponds to the site where the pathogen is localized

<p>Portals of exit</p> Signup and view all the answers

what are the different modes of transmission

<p>Direct and indirect</p> Signup and view all the answers

occurs through skin-to-skin contact, kissing, and sexual intercourse.

<p>Direct contact</p> Signup and view all the answers

refers to spray with relatively large, short-range aerosols produced by sneezing, coughing, or even talking.

<p>Droplet spread</p> Signup and view all the answers

refers to the transfer of an infectious agent from a reservoir to a host by suspended air particles, inanimate objects (vehicles), or animate intermediaries (vectors)

<p>Indirect transmission</p> Signup and view all the answers

an indirect transmission that occurs when infectious agents are carried by dust or droplet nuclei suspended in air

<p>Airborne transmission</p> Signup and view all the answers

a type of indirect transmission that indirectly transmit an infectious agent include food, water, biologic products (blood), and fomites (inanimate objects such as handkerchiefs, bedding, or surgical scalpels)

<p>Vehicles</p> Signup and view all the answers

a type of indirect transmission that indirectly transmits an infectious agent includes food, water, biologic products (blood), and fomites (inanimate objects such as handkerchiefs, bedding, or surgical scalpels)

<p>Vehicles</p> Signup and view all the answers

such as mosquitoes, fleas, and ticks may carry an infectious agent through purely mechanical means or may support growth or changes in the agent.

<p>Vectors</p> Signup and view all the answers

• refers to the manner in which a pathogen enters a susceptible host.

<p>Portal of entry</p> Signup and view all the answers

Susceptibility of a host depends on genetic or constitutional factors, specific immunity, and nonspecific factors that affect an individual’s ability to resist infection or to limit pathogenicity.

<p>Host</p> Signup and view all the answers

Study Notes

Epidemiology

  • The study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.
  • A method of causal reasoning based on developing and testing hypotheses grounded in scientific fields such as biology, behavioral sciences, physics, and ergonomics to explain health-related behaviors, states, and events.

Epidemiologic Functions

  • Characterize the amount and distribution of disease within and across populations.
  • Determine the relevance, effectiveness, efficiency, and impact of activities with respect to established goals.
  • Participate in field investigations to identify the cause of an epidemic.
  • Design and conduct analytic studies to evaluate the credibility of hypotheses.
  • Develop and test hypotheses about the causes and modes of transmission of diseases.

Public Health Surveillance

  • The ongoing, systematic collection, analysis, interpretation, and dissemination of health data to help guide public health decision-making and action.
  • Requires the coordinated efforts of dozens of people to characterize the extent of an epidemic and to identify its cause.

Field Investigation

  • Also known as field epidemiology.
  • Often used in combination with surveillance and analytic studies to provide clues or hypotheses about causes and modes of transmission.

Research Strategy and Study Design

  • Involves determining the appropriate research strategy and study design.
  • Writing justifications and protocols.
  • Calculating sample sizes.
  • Deciding on criteria for subject selection.
  • Securing appropriate clearances and approvals.
  • Describing the characteristics of the subjects.

Descriptive Epidemiology

  • Characterizes the amount and distribution of disease within and across populations.
  • Common variables involved include person, place, and time.
  • The 5 W's of descriptive epidemiology are: who, what, where, when, and why.

Analytic Epidemiology

  • Refers to the study of the determinants of health-related outcomes.
  • Anticipated direction of effect is specified.
  • No direction is specified.
  • Frequently used to evaluate research hypotheses.

Measures of Effect

  • Compares the incidence rate (IR) among the exposed to the incidence rate among the non-exposed (IRE/IRNE).
  • Compares the incidence proportion (risk) among exposed to the incidence proportion among the non-exposed (IE/INE).
  • Compares the odds of exposure among those with the health outcome of interest to the odds of exposure among those without the health outcome.

Evaluating Associations

  • Refers to the likelihood of observing an apparent exposure/health outcome relationship, when in fact, one does not truly exist.
  • Refers to systematic error in the conduct of a study.
  • Errors due to bias can occur.

Bias

  • 7 types of bias:
    • Selection bias: occurs when dissimilar procedures are used to select study subjects, and such procedures relate to the exposure or health outcome under study.
    • Referral bias: occurs when subjects are differentially referred into a study based on knowledge of their exposure status.
    • Information bias: refers to different types of errors in the manner in which information is collected.
    • Outcome misclassification bias: occurs when outcome misclassification differs among persons exposed or not exposed, or similarly, exposure misclassification differs among case subjects and control subjects.
    • Non-differential error bias: occurs when the magnitude is unrelated to exposure or outcome status.
    • Recall bias: occurs when subjects in the study groups formed recall of their exposure or outcome history differently.
    • Interviewer bias: occurs when individuals involved in the collection of exposure or outcome data probe for or record information in a differential manner.
    • Social desirability bias: refers to selective suppression or revealing of information, including sensitive information and information related to attitudes, beliefs, and perceptions.
    • Recall bias: refers to incorrect classification of the presence of an exposure that occurs after the onset of the health outcome under study, rather than before it.

Epidemiological Studies

  • 2 categories:
    • Experimental studies: the investigator determines through a controlled process the exposure for each individual or community, and then tracks the individuals or communities over time to detect the effects of the exposure.
    • Observational studies: the investigator simply observes the exposure and disease status of each study participant.

Infectious Disease Causation

  • The agent: originally referred to an infectious microorganism or pathogen, such as a virus, bacterium, parasite, or other microbe.
  • The host: refers to the human who can get the disease.
  • The environment: refers to extrinsic factors that affect the agent and the opportunity for exposure.
  • The chain of infection: was proposed by Rothman in 1976, and has come to be known as the epidemiological triad.

Chain of Infection

  • The reservoir: the habitat in which the agent normally lives, grows, and multiplies.
  • The portal of exit: the path by which a pathogen leaves its host.
  • The mode of transmission: the way in which the agent is transmitted from the reservoir to a susceptible host.
  • The portal of entry: the manner in which a pathogen enters a susceptible host.

Modes of Transmission

  • Direct transmission: occurs through skin-to-skin contact, kissing, and sexual intercourse.
  • Droplet transmission: refers to spray with relatively large, short-range aerosols produced by sneezing, coughing, or even talking.
  • Airborne transmission: refers to the transfer of an infectious agent from a reservoir to a host by suspended air particles, inanimate objects, or animate intermediaries.
  • Indirect transmission: includes food, water, biologic products, and fomites.
  • Vector transmission: includes animals such as mosquitoes, fleas, and ticks that may carry an infectious agent through purely mechanical means or may support growth or changes in the agent.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser