Question

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 RD= Estimate the relative risk in pain relief between treatments RR = Estimate the odds ratio in pain relief between treatments OR = The upper and lower limits of the are shown below Lower Limit of CI: ____0.41____ Upper Limit of CI: ___1.61_____ 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 ?

Answer 1

To estimate the risk difference (RD), divide the proportion of participants experiencing pain relief for the new medication and placebo. The relative risk (RR) is calculated by dividing the risk in the new medication group by the risk in the placebo group. The odds ratio (OR) is determined by dividing the product of ad/bc by the product of ac/bd. The confidence interval values indicate that the true value of the risk difference in pain relief is likely to be between 0.41 and 1.61.

Step-by-step explanation:

To estimate the risk difference (RD) between the new medication and placebo in pain relief, we need to calculate the difference in the proportion of participants experiencing pain relief between the two treatments.

RD = (44/164) - (21/120) = 0.268 - 0.175 = 0.093

To estimate the relative risk (RR), we divide the risk of pain relief in the new medication group by the risk in the placebo group.

RR = (44/164) / (21/120) = 0.268 / 0.175 = 1.531

To estimate the odds ratio (OR), we divide the product of the ad/bc by the product of the ac/bd.

OR = (44/120) / (21/76) = 2.151

Based on the confidence interval values, we can conclude that the true value of the risk difference in pain relief between treatments is likely to be between 0.41 and 1.61.

Therefore, the correct answer is C. One can be 95% confident that the true value will be between the upper and lower limit.