A clinical trial is conducted comparing a new pain medication for arthritis. Participants are randomly assigned to receive the new medication or a placebo. The outcome is pain relief within 30 minutes. The data are shown below.
Pain Relief No Pain Relief
New Medication 44 76
Placebo 21 99
Estimate the risk difference in pain relief between treatments
=
Estimate the relative risk in pain relief between treatments
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Estimate the odds ratio in pain relief between treatments
=
The upper and lower limits of the are shown below
Lower Limit of CI: _______
Upper Limit of CI: ________
Based on the Confidence Interval values which of the following are true?
A. One can be 95% confident that the true value will be greater than the upper limit.
B. One can be 95% confident that the true value will be greater than the lower limit.
C. One can be 95% confident that the true value will between the upper and lower limit.
D. a and b
2. The following data were collected in a clinical trial evaluating a new compound designed to improve wound healing in trauma patients. The new compound is compared against a placebo. After treatment for 5 days with the new compound or placebo the extent of wound healing is measured and the data are shown below.
Percent Wound Healing
Treatment 0-25% 26-50% 51-75% 76-100%
New Compound (n=125) 15 37 32 41
Placebo (n=125) 36 45 34 10
Is there a difference in the extent of wound healing by treatment? (Hint: Are treatment and the percent wound healing independent?) Run the appropriate test at a 5% level of significance.
df= ________
alpha= _______
Reject H0 if χ2> ________
Compute expected frequencies
Expected Frequency = (Row Total * Column Total)/N.
Complete the expected frequencies for each cell.
Percent Wound Healing Total
Treatment 0-25% 26-50% 51-75% 76-100%
New Compound 15
37
( ) 32
() 41
( ) 125
Placebo 36
(25.5 ) 45
( ) 34
( ) 10
() 125
Total 51 82 66 51 250
Compute χ2.
χ2= ______
Based on comparing the computed χ2 to the rejection level χ2 which of the following is (are) true?
A. We have statistically significant evidence at alpha=0.05 to show that H0 is false.
B. Treatment and percent wound healing are not independent.
C. Treatment and percent wound healing are independent.
D. a and b.
3. A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo. Participants are randomly assigned to receive the new treatment or a placebo and the outcome is pain relief within 30 minutes. The data are shown below.
Pain Relief No Pain Relief
New Medication 44 76
Placebo 21 99
Is there a significant difference in the proportions of patients reporting pain relief? Run the test at a 5% level of significance.
Reject H0 if Z < _______ or if Z > ________
alpha= ________
= ________
= ________
= ________
Z = _______
Based on comparing the computed z to the rejection level z which of the following is (are) true?
A. We have statistically significant evidence at alpha=0.05 to show that H0 is false.
B. We have statistically significant evidence at alpha=0.05 to show that there a significant difference in the proportions of patients reporting pain relief.
C. We do not have statistically significant evidence at alpha=0.05 to show there a significant difference in the proportions of patients reporting pain relief.
D. a and b #question..