PH 101 - 8% Flashcards
An Introduction to Epidemiology
Epidemiology definition
the study of distribution and determinants of health-related states among specified populations and the application of that study to the control of health problems
What are the steps in a public health approach?
- surveillance - What is the problem?
- Risk factor identification - What is the cause?
- Intervention Evaluation - What works?
- Implementation - How do you solve the problem?
What are the public health core sciences
- Prevention Effectiveness
- epidemiology
- laboratory
- informatics
- surveillance
what are the purposes in public health of epidemiology?
- discover the agent host and environmental factors that affect health
- determine the relative importance of causes of illness, disability, and death
- identify the segments of the population that have the greatest risk of getting sick
- evaluate the effectiveness of health programs and services improving population health
What are the 4 steps in solving health problems?
- Data Collection - surveillance (determine the time, place and person)
- Assessment - Inference
- Hypothesis testing - determine how and why
- Action - intervention
epidemic or outbreak definition
disease occurrence among a population that is in excess of what is expected in a given time and place
cluster definition
group of cases in a specific time and place that might be more than expected
endemic definition
disease or condition present among a population at all times
pandemic definition
a disease or condition that spreads across regions
rate definition
number of cases occurring during a specific period ; always dependent on the size of the population during that period
why are rates helpful?
rates help us compare health problems among different populations that include two or more groups who differ by a selected characteristic
rate formula
rate(%) = number of cases
———————— x 100
population at risk
OR
rate(%) = number of cases/population at risk x100
What should be determined first to being calculating the rate of an outbreak.
The number of cases of illness
What do you need to calculate a rate?
the frequency -> the number of cases of the illness or condition, the size of the popuation at risk, the period during which we are calculating the rate
What are the branches of epidemiology study types?
1st level: experimental and observational
2nd level: (under observational) descriptive and analytic
what questions does descriptive epidemiology ask?
- When was the population affected?
- Where was the population affected?
- Who was affected?
What question does analytic epidemiology ask?
- How was the population affected?
- Why was the population affected?
- somtimes comparing 2 groups???
What are the 4 types of data sources?
- Individual persons
- environment
- health care providers
- non-health related sources (financial, legal)
what are methods of data collection for individual persons?
- questionnaire
- survey
what are methods of data collection for environment?
- samples from the environment (river, water, soil)
- sensors for environmental changes
what are methods of data collection for health care providers?
notifications to health department if cases of certain diseases are observed
what are methods of data collection for non-health related sources?
- sales records
- court records
Why are studies conducted
studies are conduction in an attempt to discover associations between an exposure or risk factor and a health outcome
How are participants selected for a cross-sectional study?
they are selected because they are members of a certain population subset at a certain time
What are the types of studies?
- cross-sectional study
- cohort study
- case control study
how are participants categorized in a cohort studies?
they are categorized on the basis of their exposure to one more risk factors
How to case-control studies work?
subjects identifies as having a certain disease or condition are compared to subjects without the same disease or condition (ONLY FOR CONDITIONS NOT FOR LIFESTYLES OR OTHER THINGS)
What are the steps involved in outbreak investigations?
- establishing the existence of an
outbreak - preparing for fieldwork
- verifying the diagnosis
- defining and identifying cases
- using descriptive epidemiology
- developing hypotheses
- evaluating the hypotheses
- refining the hypotheses
- implementing control and prevention
measures - communicating findings
How many steps are there in outbreak investigation?
10
What is step one in outbreak investigation? How do you it?
establishing the existence of an outbreak. You use data from data sources
What is step two in outbreak investigation? How do you it?
Preparing for field work.
- research the disease
- gather supplies and equipment
- arrange travel
What is step three in outbreak investigation? How do you it?
verifying the diagnosis
- speak with patients
- review laboratory findings and clinical test results
What is step four in outbreak investigation? How do you it?
defining and identifying cases
- establish a case definition by using a standard set of criteria
What is step five in outbreak investigation? How do you it?
using descriptive epidemiology
- describe and orient the data
What is step six in outbreak investigation?
develop a focused hypothesis
What is step seven in outbreak investigation?
evaluate the hypothesis for validity
What is step eight in outbreak investigation?
refine the hypothesis as needed
What is step nine in outbreak investigation? How do you it?
implement and control and prevention and measures
- control and prevent additional cases
