[ad_1]
1. In an outbreak of gastroenteritis among attendees of a corporate picnic, 99 persons ate potato salad, 30 of whom developed gastroenteritis. Calculate the risk of illness among persons who ate potato salad.
a. 32.3 %
b. 31.3 %
c. 30.3%
d. 29.3%
2. A population at risk is composed of 100 senators. Twenty-five senators develop symptoms consistent with inhalation anthrax disease and are confirmed by laboratory testing to have been infected with Bacillus anthracis. If 12 senators developed anthrax in September and 13 developed anthrax in October, what is the incidence rate of anthrax for those two months?
a. 14%
b. 10%
c. 18%
d. 16%
3. A case-control study of 1700 participants looked at the association between Tamoxifen and uterine cancer. The study included 689 cases. There were 139 cases and 58 controls taking Tamoxifen.
a. Fill in the 2×2 table below.
| Uterine Cancer | ||
| Tamoxifen | Yes | No |
| Yes | ||
| No |
b. Calculate the odds ratio of the above study.
a. 4.01
b. 4.15
c. 4.35
d. 4.51
c. Interpret the measure of association. Select which is the best interpretation:
a. Odds Ratio is Less than 1.0, Tamoxifen is not a risk for uterine cancer
b. Odds Ratio is Greater than 1.0, Tamoxifen is a risk for uterine cancer
c. People that use Tamoxifen have a 4.15 greater risk of developing uterine cancer compared to people who do not take Tamoxifen
d. People that use Tamoxifen have a 4.15 reduced risk of developing uterine cancer compared to those people who do not take Tamoxifen
e. B and C are true
4. A 4th grade class in Salem, Massachusetts has 20 students. Due to recent media coverage of the fallacious association between vaccines and autism, none of the students have been immunized against influenza this year. Fortunately, up to this point none of the students has come down with the flu. During the first week of flu season, however, 2 students contract influenza. In the second week, 3 more students contract influenza. And in the third week, 5 more students contract influenza. The other students remained healthy throughout the rest of the flu season. In this class, what was the risk of contracting influenza during the second week of the flu season?
a. 0.27
b. 0.17
c. 0.37
d. 0.11
5. A study was conducted to examine risk factors for spontaneous pneumothorax (collapsed lung), including use of car air fresheners. 430 emergency room cases were identified from Florida hospitals in 2005, and 1204 controls were sampled from the patients admitted to the emergency room for broken bones or lacerations. It was found that 110 of the cases and 214 of the controls used a car air freshener regularly. The remaining cases and controls did not use air fresheners in their car.
a. Construct the appropriate 2×2 table for this study using the information given.
b. Calculate the odds of being a case among the unexposed.
a. 0.32
b. 0.41
c. 0.03
d. 0.39
c. Calculate the odds ratio.
a. 1.2
b. 1.9
c. 2.4
d. 1.
6. A study of gym members was undertaken to see if machine-users were more prone to injury than free-weight users. Assume for this study that you can only be injured in the gym once in your lifetime. 1500 gym patrons across the county were polled beginning January 1, 2003. On June 5, 2003, it was discovered that 75 of those gym patrons currently had gym-related injuries. After June 5, the remaining injury-free patrons were enrolled in a cohort study, classified as machine-users (n=1000) and free-weight users (n=425), and followed for 3 years. 85 machine-users and 15 free-weight users became injured in the 3 years. All follow-up stopped on exactly June 5, 2006. Assuming complete ascertainment and no drop-outs:
a. Calculate the point-prevalence of injury on June 5, 2003
a. 0.05
b. 0.10
c. 0.12
d. 0.01
b. Calculate the relative risk of injury among machine users compared to free-weight users.
a. 2.1
b. 2.4
c. 1.4
d. 2.9
7. The incidence rate of post-partum depression among 250,000 women who recently experienced a pregnancy was 12 cases per 100,000 woman-years of follow-up. Exactly how many incident cases of post-partum depression developed in this population?
a. 30 cases
b. 35 cases
c. 15 cases
d. 23 cases
8. State which method to control for confounding is being used for the following scenario: A study of exercise and myocardial infarction that is limited to men. (Note: exercise is the exposure, myocardial infarction is the disease, and gender is the confounder)
a. Matching
b. Restriction
c. Stratified Analysis
d. Multivariate Analysis
9. Selection bias is most likely to occur in
a. Retrospective Cohort studies
b. Experimental Studies
c. Case Control Studies
d. A and B
e. A and C
10. Recall bias is most likely to occur in
a. Prospective Cohort studies
b. Case control studies
c. Experimental studies
d. None of the above
11. True or False. A retrospective cohort study is more efficient than a prospective cohort study for studying diseases with a long latent and induction period.
a. True
b. False
12. True or False. The main limitation of observational studies is the investigator’s inability to have complete control of extraneous factors called cofounders.
a. True
b. False
The post Calculate the odds ratio appeared first on Scholar Writers.
[ad_2]
Source link
"96% of our customers have reported a 90% and above score. You might want to place an order with us."
