Module 5 Flashcards
What are some health-related purposes of observational research?
- Answer questions of test hypotheses about a single variable rather than a statistical relationship between 2 variables
- Answer research question about a non-causal statistical relationship between variables
- If independent variable cannot be manipulated or participants cannot be randomized - Causal relationships can ONLY be examined using observational designs
- Answer broad and exploratory research questions
What is the goal of observational research?
To identify areas for further study of to draw inferences about relationships by collecting information about exposures (Independent variables) and outcomes (dependent variables)
What are some “flaws” of observational research?
no randomization and no control over the environment
Why must alternate explanations be considered for observational quantitative studies?
No randomization
No control over the environment
Do observational quantitative studies always test a hypothesis?
no, not if it is descriptive
What is epidemiology?
Study of how and why different patterns of health and disease occur among various subgroups in a population
What are the 3 Ds in the 3D definition of epidemiology?
Distribution
Determinants
Deterrents
What is distribution?
Frequency and patterns of morbidity and mortality in a given population or community
What are determinants?
Factors that contribute to morbidity and mortality in human populations
What are deterrents?
Factors that prevent of reduce morbidity and premature mortality in human populations
What are the 2 subdivision of observational epidemiology?
Analytic
Descriptive
What is descriptive epidemiology?
Describe the frequency and distribution of determinants and deterrents of morbidity and mortality in a given population or community by person, place, and/or time
- Used to help inform health programs and services, identify health-related issues and trends, and suggests hypotheses for further study
- Who What When Where -
What is analytic epidemiology?
Observational methods are used to uncover the relationship between suspected determinants or deterrents or morbidity and mortality (exposures) in a given population of community
Used to identify risk factors for disease and explain disease patterns in a population
- How Why-
Why are observational studies conducted?
- Collect descriptive information (how many people have a disease)
- Study the potential effects of exposures on disease outcomes
- Investigate a problem without interfering with the natural setting
- Learn about health risk or benefits in humans when a experiments study is not feasible or unethical
What is clinical equipoise in experimental study and why is it important?
There can be neither enough enough for or against a treatment to preclude its use as an intervention in research. If this isn’t met only observational study can examine the relationship between exposures and outcomes.
eg: you can’t make people smoke to study effects of cigarettes OR you cant withhold insulin from Type 1 diabetic to see what happens.
What is the main assumption about disease distribution?
They do not distribute randomly in populations, but distribute in relation to their determinants; therefore, determinants of diseases can be identified by studying their distributions
Describe sampling in Observational studies
They take samples from a study population. These subsets are “randomly selected” (each member of the population has a known probability of getting selected)
In epidemiology, what are exposures?
Independent variables
Usually risk factors, but are understood as ANY factor that might influence health positively or negatively
In epidemiology, what are outcomes?
Dependent variables
Usually diseases, but are understood as ANY type of health state (pregnancy, health behaviours, perception of well-being)
What is an “Association” in epidemiology?
Mathematical relationship representing the amount of dependence between 2 variables (exposure and outcomes)
What are the 3 types of associations in epidemiology?
Spurious
Non-causal
Causal
What is a spurious association?
The association is simply not true. Can be caused by random error or by bias
What are non-causal associations?
Real associations statistically, however it is due to other factors eg One did not cause the other
What are causal relationships?
When changes occur in the occurrence of the outcome can be shown to be the direct result of an exposure