Designing an Epidemiologic Study to Test the Hypothesis
To test the hypothesis on the source of the outbreak, a case-control study was conducted from July 21-27. Thirty-one of the initial 38 persons meeting the original case definition (i.e., those not used in hypothesis-generating interviews) were included as cases. It was decided that two controls would be selected for every case and would be matched to the case by age group (0-<2 years, 2-<5 years, 5-<12 years, 12-<18 years, 18-<60 years, and 60+ years) and gender.
The investigators identified controls for the study using sequential digit dialing. Exposure information among cases was collected for the 7 days before onset of illness. For controls, exposure information was collected for the 7 days before the interview and for the 7 days before the onset of illness in the matching case.
Twenty-seven case-control sets were interviewed; the remaining case-patients could not be reached.
Please answer these questions: (use subheadings)
1. How would you define controls for this study? What methods might be used to identify controls?
2. Do you agree with the investigators’ decision to match on age group and gender? Why or why not?
3. Over what time period would you examine exposures to possible risk factors for cases? For controls?
Length: Assignments should be at least 4 pages (1000 words) in length, scholarly sources required.
Centers for Disease Control and Prevention. (2012). Lesson one: Introduction to epidemiology: Section 6: Descriptive epidemiology. In Principles of Epidemiology in Public Health Practice, 3rd Edition. Retrieved May 1, 2019, from https://www.cdc.gov/csels/dsepd/ss1978/lesson1/section6.html
Centers for Disease Control and Prevention. (2012). Lesson one: Introduction to epidemiology: Section 7: Analytical epidemiology. Principles of Epidemiology in Public Health Practice, 3rd Edition. Retrieved May 1, 2019, from https://www.cdc.gov/csels/dsepd/ss1978/lesson1/section7.html
Coggon, D., Rose, G., & Barker, D. J. P. (2007) Chapter 8: Case-control and cross sectional studies. In Epidemiology for the Uninitiated (4th edition). British Medical Journal. Retrieved on May 22, 2012, from http://www.bmj.com/about-bmj/resources-readers/publications/epidemiology-uninitiated
Herbert, R. (2017). Case-control studies. Journal of Physiotherapy, 63(4), 264-266. doi:10.1016/j.jphys.2017.08.007