Question

This case study requires only calculation and analysis of them, so you may complete this case study using SPSS or any tool you choose.

More specifically, the study had 1287 patients use Vioxx for calculation, and it had another 1299 patients use a placebo over the same period. After 18 months, 45 of the Vioxx patients had developed serious heart problems, whereas only 25 patients on the placebo developed such problems.

Given the result, would you agree with the conclusion that Vioxx caused a significant increase in the risk of developing serious heart problems?

First, answer this from a purely statistical point of view, where significant means statistically significant.

What hypothesis should you test, and how should you run the test? when you run the test, what is the corresponding P-value? Next, look at it from the point of view of patients. If you were a Vioxx user, would these results cause you significant worry? After all, some of the subjects who took placebos also develop heart problems, and 45 might not be considered that much larger than 25. Finally, look at it from Merck’s point of view. Are the results practically significant to the company? What does it stand to lose? Develop an estimate, no matter how wild it might be, of the financial losses Merck might incur. Just think of all of those American Vioxx users and what they might

Answer 1

We have to perform test of proportion.

Suppose, denotes the proportion of patients developing serious heart problems who used Vioxx. Also denotes that for those who used placebo.

So, our testing problem is as follows.

We have to test for null hypothesis

against the alternative hypothesis

Our test statistic is given by

where

P-value = 0.006899

So, at 5% signicicance level we see P-value<0.5 and so we have to reject the null hypothesis.

From statistical point of view, we conclude that Vioxx caused significant increase in the risk of developing serious heart problems.

From the point of view of patients, patients neither perform statistical computation nor compare according as proportions. They merely compare observed data. As number of heart problems is significantly higher in case of using Vioxx, they will conclude that Vioxx caused significant increase in the risk of developing serious heart problems.

From the point of view of the company, it is observed that patients are possessing negative attitude towards Vioxx. So, the result is significant enough to gain consumer's interest. So they will perform modification in their product.