# Estimate the survival (time to progression to hypertension) functions

A clinical trial is conducted to evaluate the efficacy of a new drug for prevention of

hypertension in patients with pre-hypertension (defined as systolic blood pressure between

120–139 mmHg or diastolic blood pressure between 80–89 mmHg). A total of 20 patients are

randomized to receive the new drug or a currently available drug for treatment of high blood

pressure. Participants are followed for up to 12 months, and time to progression to

hypertension is measured. The experiences of participants in each arm of the trial are shown

below.

data is on the document. the first one

To answer the question as to whether or not there is a difference in time to progression, a

Chi square statistic is computed. The critical value for rejection of the null hypothesis is

3.84. The computed Chi square is 0.335.

Based on comparing the computed Chi square and the critical Chi square, which of the

following is (are) true?

A. There is not statistically significant evidence to show that the time to progression is

different between groups.

B. There is statistically significant evidence to show that the time to progression is

different between groups.

C. The time to progression is essentially the same for each group.

D. a and c.

The hazard ratio risk of progression to hypertension is 0.658. Based on this computation,

which of the following is (are) true?

A. The risk of progression to hypertension is reduced by 34.2% in patients assigned

to the new drug as compared to the currently available drug.

B. The risk of progression to hypertension is 1.52 times higher in patient’s current

drug as compared to the new drug.

C. The risk of progression to hypertension is 5.12 times higher in patient’s current

drug as compared to the new drug

D. a and b