In Lesson 2, we saw that the case definition can have great impact upon results and the interpretation of results. We also examined prevalence and incidence. We measured the frequency of a disease, specifically looking at 5 different ways: count, proportion, ratio, rate and risk. Each of these can be useful depending on the purpose and the study design.
In Lesson 3, we are now going look at whether or not a particular exposure is associated with increased risk or occurrence of disease, and issues related to this process and quality of that association.. This is going to begin with a definition of exposure and the process of measuring that exposure.
Sexton K; Kleffman DE; Callahan MA. Journal of exposure analysis and environmental epidemiology, (1995 Jul-Sep) Vol. 5, No. 3, pp. 229-32. Ref: 9 Journal code: 9111438. ISSN: 1053-4245.
- Use the terminology of exposure, effect and association in accordance with epidemiologic practice;
- Apply a definition of exposure to an environmental contaminant;
- Recognize potential effect modifiers in a pathway between exposure and disease;
- Develop appropriate questions to assess the level of exposure and relationship of exposure to outcome;
- Differentiate between update and intake;
- Describe advantages and disadvantages of direct monitoring;
- Identify strengths and weaknesses of 4 types of assessment of environmental exposure (questionnaires, occupational history, expert assessment, direct exposure measurements);
- Interpret a confidence interval for a rate ratio and for a difference in rates;
- Calculate a population attributable risk;
- Evaluate sources of bias, types of misclassification;
- Identify a confounded variable;
- Recognize effect modification.