Scientific Foundations: Epidemiology Flashcards
Incidence rate
An epidemiologic term that describes the occurrence of new disease or injury per unit of time among persons at risk
Incidence rate numerator
Includes only new cases of disease during a given time period
Incidence rate denominator
Includes everyone at risk of developing the disease during that period
Incidence measures…
The probability (or risk) of developing disease
Use of incidence rates
Tracking trends in the development or resolution of disease
Prevalence
An epidemiologic term that describes the proportion of the population with the condition at a given point in time or during a given time period
Prevalence numerator
Includes new and existing cases
Prevalence denominator
Includes all who are at risk for developing the disease, including those who have it
Prevalence measures…
The current burden of disease
Prevalence uses
Measuring and projecting health care and health resource needs
Applications of epidemiologic research
- Controlling infectious diseases
- Controlling the effects of chemical hazards
- Understanding genetic susceptibility to disease
- Understanding the effects of nutritional status
- Linking pathogens to specific disease processes
- Identifying risk factors for illness and injury
Evaluation of —– among exposures and health outcomes is central to epidemiology
Associations
Criteria to evaluate causality based on an observed association include the following…
- The strength of the association
- Consistency of the association
- Temporality of the association
- Dose-response relationship
- Plausibility of association
Strength of the association
Refers to the degree of correlation between the exposure and the disease
Consistency of the association
- Similar findings result across several studies of the same association
- Conclusions similar despite use of different study designs, under different conditions and in different populations
Temporality of association
-demonstrates that the cause precedes the effects
Temporality cannot be evaluated with a —— study
Cross sectional
Dose response relationship
As the degree of exposure increases, the risk for developing outcome increases