In the article “Increased Pulse Pressure and Risk of Heart Failure in the Elderly”

published in JAMA (Chae, eta al.,1999), the authors reported the results of a study on pulse pressure, an index of arterial stiffening, and congestive heart failure (CHF)

in the elderly. The information in Table 13.15 is a summary of the proportional hazards model fit for the risk of congestive heart failure and blood pressure variables.

Use the information in Table 13.15 to answer the following questions.

(a) Estimate the risk ratio associated with the variable Pulse Pressure.

(b) If the estimated standard error of the coefficient associated with Pulse Pressure is ???????? = 0.025, compute a 95% confidence interval for the risk ratio associated with the variable Pulse Pressure

(c) Estimate the risk ratio associated with the variable Systolic BP.

(d) If the estimated standard error of the coefficient associated with Systolic BP is ???????? = 0.033, compute a 95% confidence interval for the risk ratio associated with the variable Systolic BP.

(e) Are there any variables in this proportional hazards model that do not appear to be important? Explain.