Question

A clinical trial was conducted to test whether medication A could effectively be used to reduce the risk of a special disease among people with high risk. The results at the end of the study are listed on the table below

	with disease	without disease	total
medication A	99	3377	3476
placebo	174	3098	3272

Keep 4 decimal points for your calculations in Q1 - 4, 6 - 8.

1. P(disease| medication A) = Blank 1. Fill in the blank, read surrounding text. .

2. P(disease|placebo) = Blank 2. Fill in the blank, read surrounding text.

3. The relative risk for those who took medication A vs. those who took placebo is Blank 3. Fill in the blank, read surrounding text.

4. The absolute risk reduction of the disease attributable to the medication A is Blank 4. Fill in the blank, read surrounding text.

5. The number need to treat for using the medication A to prevent 1 patient with the disease is Blank 5. Fill in the blank, read surrounding text.

6. The odds of disease for those who took medication A is Blank 6. Fill in the blank, read surrounding text.

7. The odds of disease for those who took placebo is Blank 7. Fill in the blank, read surrounding text.

8. The odds ratio for those who took placebo vs. those who took medication A is Blank 8. Fill in the blank, read surrounding text.

9. The relative risk for those who took placebo vs. those who took medication A is Blank 9. Fill in the blank, read surrounding text.

10. The odds ratio for those who took medication A vs. those who took placebo is Blank 10. Fill in the blank, read surrounding text.

Answer 1

Question 1

(disease| medication A) = Blank 1. Fill in the blank, read surrounding text. .

Disease/medication A

99/99+3377

99/3476

0.028

Answer: 0.028.

Question 2

disease|placebo) = Blank 2. Fill in the blank, read surrounding text.

Disease/ Placebo

174/174+3098

174/3272

0.053

Answer: 0.053

Question 3

The relative risk for those who took medication A vs. those who took placebo is Blank 3. Fill in the blank, read surrounding text.

Formula: a/a+b / c/c+d

99/99+3377 / 174/174+3098

99/3476 / 174/3272

0.028/0.053

0.52

Answer 0.52

Question 4

The absolute risk reduction of the disease attributable to the medication A is Blank 4. Fill in the blank, read surrounding text.

1. AR (absolute risk) = the number of events (good or bad) in treated or control groups, divided by the number of people in that group.
2. ARC = the AR of events in the control group.
3. ART = the AR of events in the treatment group.

ARR (absolute risk reduction) = ARC – ART.

So,

0.028 - 0.053

- 0.025.

Answer : - 0.025

First 4 questions answered.