Assignment:
Short Answers and Calculations
1. Explain the difference between incidence and prevalence.
2. Explain the steps in research process.
3. What are the common measures of association used to test relationship between exposures and outcomes?
4. Define confounding variable or factor and provide an example of a confounding factor.
5. What are the 4 important elements of epidemiology research studies?
6. What is the difference between probability and non-probability sampling?
7. In a case-control study the association was examined between smoking and risk of Parkinson's disease. The table below provides the results. Find the following;
a. Odds ratio
b. Attributable Risk
c. Risk Ratio
d. Risk Difference
|
|
Cancer
|
No Cancer
|
|
Smokes
|
60
|
33
|
|
Non Smokes
|
40
|
65
|
8. A prospective study with a 2-year (24-month) follow-up was conducted. Results are shown in the table for individuals who either died or were censored before the end of the follow-up period. Below is the survival data for 20 participants of hypothetical prospective study
|
Follow-up time(months)
|
Events
|
|
2
|
Death
|
|
4
|
Censored
|
|
7
|
Censored
|
|
8
|
Death
|
|
12
|
Censored
|
|
15
|
Death
|
|
17
|
Death
|
|
19
|
Death
|
|
20
|
Censored
|
|
23
|
Death
|
Using the table above: Calculate for all deaths (a -c):
a. the probability of death at the exact time when each death occurred.
b. the probability of survival beyond the time when each death occurred.
c. the cumulative probabilities of survival
d. What is the cumulative incidence at the end of the follow-up period?
e. What is the cumulative survival probability at the end of the follow-up period?