Intro to epidemiology
2 pages
KINE3352
Module 4
Homework #3
A. Public Health Data sources – Please refer to the “Data Sources” slides from Module 2 for assistance with answering questions 1-4. This first activity serves to reinforce what was learned previously in the course.
1. The accuracy of what kinds of epidemiologic activities (e.g., assessing prevalence) could be affected by undercounting in the U.S. Census? (2 points)
2. In 2012, the Centers for Disease Control and Prevention announced that the prevalence of autism spectrum disorders in the U.S. increased by 78% during 2002 to 2008. What are two possible explanations for this increased prevalence? (2 points)
3. Consider if the American Psychiatric Association proposed to narrow the definition of autism. Under the proposed new definition, a person would have to exhibit at least four deficits in social interaction and at least four repetitive behaviors. This is a much stricter, narrower definition than previously used. If the new definition is adopted, very briefly state what impact would this have on the incidence of this disorder. (1 point)
4. List, explain and provide an example of each of the criteria for quality and utility of epidemiologic data. (4 points)
5. Using the websites given below, go to the National Health Interview Survey (NHIS) website and address the following: (4 points)
https://www.cdc.gov/nchs/nhis/about_nhis.htm
https://www.cdc.gov/nchs/data/factsheets/factsheet_nhis.htm
a. Briefly explain in your own words (do not just copy and paste what the website says) what is the National Health Interview Survey.
b. Give 3 examples of statistics found using NHIS survey data.
c. List 4 health issues or topics addressed in NHIS data.
d. Give an example (other than the ones listed on the website) of how NHIS data could be used to answer an epidemiological question.
B. Causation
Write “True” or “False” by or under each of the following statements according to whether you find the statement to be true or false.
1. A causal relationship between an exposure and disease cannot be established unless all of Hill’s guidelines are met.
2. Hill’s guideline of specificity means that an exposure can only cause one disease.
3. The presence of an association is indicative of a causal relationship.
4. Time order is an essential attribute of a cause.
5. Sir Bradford Hill’s nine causal guidelines should be used as rigid criteria to establish cause.
In the following section, write the letter of the response representing the Bradford Hill criterion that best represents the statement provided.
Suppose that an article was published on the relationship between artificial sweeteners and the risk of insomnia. Artificial sweeteners are in a wide variety of beverages, food and medications. Suppose that the following statements were taken from the introduction and results section of this article. Write the letter which best represents which of Bradford Hill’s guidelines is supported by each of the statements.
A. Strength of association
B. Biological plausibility
C. Consistency with other knowledge
1. Artificial sweetener exposure could have a harmful effect on biological processes because artificial sweetener interferes with the health of cells.
2. Several previously published epidemiologic studies of artificial sweetener intake have shown an increased risk of insomnia among men who consumed high levels of artificial sweetener.
3. In the current study, the risk of insomnia increased as artificial sweetener consumption increased. Compared with persons who did not ever consume any artificial sweetener, persons who had low artificial sweetener consumption had a 30% increased risk of insomnia, persons who had moderate artificial sweetener consumption had 80% increased risk, and persons who had high artificial sweetener consumption had a 150% increased risk.
C. Calculations and Interpretation
Problem 1:
Table 2. Incidence of Mycobacterium Tuberculosis Infection Among Congregated Persons in a Homeless Shelter by Dormitory Wing — Los Angeles, 2014
|
Developed Tuberculosis? |
|||
|
Yes |
No |
Total |
|
|
East Wing |
32 |
14 6 |
178 |
|
West Wing |
6 |
141 |
147 |
|
38 |
287 |
325 |
In an outbreak of tuberculosis among homeless shelter residents in Los Angeles in 2014, 32 of 178 people residing on the East wing of the dormitory developed tuberculosis, compared with 6 of 147 people residing on the West wing. Of those contracting tuberculosis in the East wing, 2 suffered complications and died. Use the data in Table 2 to calculate the responses for “a” through “c.”. Please include formulas for attack rate and case fatality rate in your answers.
a. attack rate for the East wing
b. attack rate for the West wing
c. case fatality rate for the East wing