WEEK 6: DESIGN 1 Flashcards
what are the two types of population/clinical health research
descriptive, analytic
what is descriptive population/clinical health research
- identify and count cases of disease in populations according to person, place, and time, and conduct simple studies
Case reports & series
Cross-sectional study & ecological study (can also be analytic)
1. To monitor the public’s health
2. To evaluate the success of intervention programs
3. To generate hypotheses about causes of disease
analytic population/clinical Health Research
Compare group and systematically determine if there is an association
Experimental study
Clinical trial
Community trials
Case-control study
Cohort study
1. To evaluate hypothesis about the causes of disease
2. To evaluate the success of intervention programs
6 components of a study
- population
- exposure
- outcome
- potential cofounders
- analysis
- communication of findings
what is a source population
the population you are interested in knowing more about
study population
the [population you enroll in your study to represent the source population
what is generalizability
assuming the association in a study reflects the truth, to whom does it apply?
what is case definition
description of the event you are interested in studying; can be disease, defect, injury, event, state
ex. a man with cardiovascular disease defined by ICD codes
- ex. an infant with structural abnormality of the heart identified within 1st week of life
target population.
people you want your results to apply to
- ex. everyone living in australia
source population or sampling frame
people from whom the population is selection
- ex. everyone on australian electoral roll
what is a cofounder
- extraneous risk factor for an outcome can be constitutional, environmental, or behavioral
Can lead to distortion of true association b/w exposure and disease
exposure component
determinant of interest upon which an outcome depends can be constitutional, environmental or behavioural
- cigarette smoker, fitness enthusiast, high fiber diet
analysis component
examination of your study data; estimation of measures of disease frequency and association
* Describe your study population (proportion of rates, exposures)
* Crude estimates (if no cofounding)
* Adjusted estimates (if cofounding)
o Standardization
o Stratified analysis
o Multivariate analysis
communication of findings component
tell the appropriate persons or community what you found even if you found no association
*Peer reviewed journals
*Conferences and meetings
*Government reports
*What about popular and social media?
sign vs symptom
Sign: an objective indication of disease that can be clinically observed, such as a rash, cough, fever, or elevated blood pressure
Symptom: a subjective indication of illness that is experienced by an individual but cannot be directly observed by others
what is a case series
a report that describes a group of individuals who have the same health issue
- Goal is to report, not research question, not theory
- The main scientific part: defining the case
o Based on a list of the inclusion and exclusion criteria individuals will be classified as a case (diagnosed)
what is a case report
a report of health issues In one patient
* A disease, disorder, or undergoing a procedure
types of analytic studies
experimental: investigator actively manipulates which groups receive agent under study (clinical community trial)
observational: investigator observes as nature takes its course (cohort, case control)
prevalence
the percentage of members of a population who have a given health issue at the time of a study
point prevalence vs period prevalence
Point prevalence: the proportion of a population with a particular characteristic at one point in time
Period prevalence: the proportion of a population with a particular characteristic during a defined time period, such as several weeks or several months
limitations to cross sectional studies
- Can not be used to assess causality
- An exposure can be said to be “associated” or “related” to a disease, but a cross-sectional study cannot show that an exposure caused a disease
what is a repeated cross sectional study
a series of cross-sectional studies that re-sample and re-survey representatives from the same source population at two or more different time points
correlational studies
the unit of analysis is the group not the individual. The group or ecological unit, represents an aggregate of individuals
ecological fallacy
a mistaken belief, especially one based on unsound argument
- The experience of individuals in a population can vary significantly from the population average
cohort study
Compare rates of a new (incident) disease in people with different exposure histories or follow a population forward in time to look for incident cases of disease
primary, secondary and teritary study
primary: collects new data from individuals
secondary: analyzes an existing data set or existing health records
teritary: reviews and synthesizes the existing literature on a topic
analytic epidemiology
studies seek to identify the risk factors (protective factors) for adverse health outcomes or test the effectiveness of interventions intended to improve health status
descriptive epidemiology
observational studies that quantify how often various health-related exposures and outcomes occur in a population
illness definition
described how a person perceives their own experience of having an adverse health condition
sickness definition
describes how a person with an adverse health condition relates to and is regarded by their community
ICD Codes
iagnostic categorizations based on the international classification of diseases (ICD) (also called international statistical classification of diseases and related health problems
PPTs
person, place, and time characteristics that set the context for a case series or for other types of descriptive epidemiology studies
Which of the following can only be written and disseminated when a researcher has access to an appropriate source of cases and when there is a compelling reason to write about those cases?
case series
representativeness
the degree to which the participants in a study are similar to the source population from which they were drawn
active vs passive. surveillance
Active Surveillance - process of public health officials contacting healthcare providers in their jurisdictions to ask how often clinicians are diagnosing particular types of disease
Passive Surveillance - compilation of reports of notifiable diseases diagnoses submitted by medical labs
prevalence ratio (PR)
- compares prevalence of a characteristic in 2 independent populations (or independent subpopulations of study participants) by taking a ratio of their prevalence rates
Spearman Rank-Order Correlation
used when examining the correlation bw variables that assign a rank to responses or that have ordered categories (scales that range from 1=stringly disagree to 5= strongly agree)
Which of the following refers to the incorrect distribution of population-level association to individuals?
Ecological Fallacy
