Lecture 4, part 3 Flashcards
At what point in the natural hx of dz would you use pt interviews/questionnaires for data?
Sx but not formal dx
At what point in the natural hx of dz would you use clinical records for data?
Seeking care or dx
At what point in the natural hx of dz would you use clinical records, registries, or notifiable dz records for data?
Diagnosed, and captured in those sources
At what point in the natural hx of dz would you look at vital statistics for data?
Outcome
What is the main purpose of notifications?
They aid in the timely control of specific health problems or hazardous conditions
Elements of descriptive epidemiology
Discerning patterns of dz incidence by person, place and time
-Who is getting the dz?
-Where is it occurring?
-How is it changing over time?
Aspects of descriptive epidemiology
Understanding the health status of a pop, burden of dz
Planning, implementation, and evaluating PH programs
Formulate hypotheses about the causes of dz
Aspects of analytic epidemiology
The search for the causes and effects, or the why and how
Seek to quantify associations between exposures and outcomes and to test hypothesis about causal relationships
Elements of using descriptive epidemiology to generate hypotheses about the causes of dz
Explore similarities and/or differences btwn those with the dz and those without the dz
Design studies to further study/test these hypotheses
Definition of an outbreak
The localized occurrence of cases of dz in excess of what would normally be expected in a defined community, geographic area, or season
-An unusually high occurrence of dz
-May be geographically concentrated or widespread
-May last for a few days, weeks, or several years
How can outbreaks vary?
In terms of scale because it’s based on the scenario
Cluster definition
Aggregation of cases in a given area over a particular period without regard to whether the number of cases is more than expected
Epidemic definition
Widespread occurrence of more cases of dz than expected in a given area or among a specific group of ppl
Pandemic definition
Epidemic that occurs across several countries and affects a sizeable portion of the pop in each
Outbreak identification sources
Review routinely collected surveillance data
-Mandatory reporting of certain “notifiable” dzs
Observation of single events or clusters by clinicians, infection control practitioners, or laboratorians
Reports by one or more pts or members of the public
Outbreak investigation steps
Detect outbreak and find cases
Generate and test hypothesis about causes
Develop management/control plans
Considerations of an outbreak
When should a suspected outbreak be investigated?
OB ixs are almost always public events
What to take into consideration with when a suspected OB should be investigated
Public, political, and legal concerns
When is something called an “outbreak”? An “epidemic”?
What to take into consideration given that OBs are almost always public events
Clear and effective communication (misinformation/fear)
Concordance with PH law
Diplomacy- not all parties are always cooperative
Steps of epidemiologic analysis for OBs
Define the epidemic
Perform descriptive epidemiology
Develop and test hypotheses (epi analysis)
Aspects of defining the epidemic for OBs
Create a case definition
Count the cases (numerator)
Determine the pop at risk for developing the dz (denominator)
Calculate attack rates (when possible)
Aspects of performing descriptive epidemiology for OBs
Examine the distribution of cases in terms of person, place, and time
Look for interactions of relevant variables
Trends of who is impacted, common exposures, etc
Aspects of developing and testing hypotheses in OBs
Based on existing knowledge of the dz (if any)
Analyze existing data using an appropriate study design
Collect additional data
Use results to recommend control measures
Definition of case definition
A standardized set of criteria for determining whether a person has a dz for case counting purposes
What can criteria of a case definition be based on?
S/sx, physical findings
Lab tests
Medical hx, exposure hx
What should be considered when designing an OB ix or study?
Practical and theoretical considerations
“Gold standard” measure from previous reasearch?
What is the purpose of ID’ing, investigating, and controlling OBs?
