Question

BEYOND THE NUMBERS 3.18 LEARNING OUTCOMES 4 TO 7 Statistical Significance in the Media-Part II Name: Section Number: To be graded all assignments must be completed and submitted on the original book pope. EXHIBIT 1 Prescription to Pass Drug Safety Title: Trial Intensifies Concerns about Safety of Vytorin Author: Alex Berenson Source: New York Times, July 22, 2008, http://www.nytimes.com/2008/07/22/ business/22drug.html The following is an extract from a New York Times article on vytorin: In a clinical trial, the cholesterol-lowering drug vytorin did not help people with heart-valve disease avoid further heart problems but did appear to increase their risk of cancer, scientists reported Monday Vytorin and Zetla, a companion drug, are prescribed each month to almost three million people worldwide and are among the world's top-selling medicines, In the Seas trial, which involved nearly 1,900 patients whose heart valves were partially blocked participants were given either vytorin or a placebo pill that contained no medicine. Scientists hoped that the trial would show that patients taking Vytorin would have a lower risk of needing valve replacement surgery or having heart failure. But the drug did not show those benefits. "No significant difference was observed between the treatment groups for the combined primary endpoint," Dr. Terje Pedersen, the principal investigator for the study and a professor medicine at Ulleval University Hospital in Norway, said. The primary endpoint is the result that scientists hope to prove when they conduct a clinical trial. However, patients taking Vytorin in the Seas trial did have a sharply higher risk of developing and dying from cancer. In the trial 102 patients taking vytorin developed cancer, compared with 67 taking the placebo. Of those, 39 people taking Vytorin died from their cancer, compared with 23 taking placebo. The absolute numbers of cancer cases were relatively small. But they reached statistical significance, meaning the odds were less than 5% that they were the result of chance. BEYOND THE NUMBERS 3.18 281

Answer 1

The Significant difference: Here the two outcomes that are compared are

1. Those patients who need valve replacement

2. Those patients who had heart failure.

In statistical significance: The following are compared:

1. Development of cancer

2. Dying from cancer from those patients in whom the cancer developed