A medical researcher is interested in assessing the probability of some symptoms of coronary heart disease (CHD)being present at a given age.For this reason he uses the following data collected on 100 individuals. Thus,the variable under study is CHD that assumes a value of 1 if coronary heart disease is present,and a value of 0 otherwise.Using Excel and Minitab,the following linear and logistics regression equations have been estimated: Linear Regression: = - 0.53796 + 0.02181Age
Logistic Regression: Using the logistic equation,what is the estimated probability of coronary heart disease for a 60-year-old individual?
A) 0.4581
B) 0.3219
C) 0.7706
D) 0.7946

Question

A medical researcher is interested in assessing the probability of some symptoms of coronary heart disease (CHD)being present at a given age.For this reason he uses the following data collected on 100 individuals.  Thus,the variable under study is CHD that assumes a value of 1 if coronary heart disease is present,and a value of 0 otherwise.Using Excel and Minitab,the following linear and logistics regression equations have been estimated: Linear Regression:  = - 0.53796 + 0.02181Age
Logistic Regression:  Using the logistic equation,what is the estimated probability of coronary heart disease for a 60-year-old individual?
A) 0.4581 
B) 0.3219 
C) 0.7706 
D) 0.7946

Quizplus · Accepted Answer

To use the logistic regression equation to estimate the probability of CHD for a 60-year-old individual, we substitute Age = 60 into the equation:
P(CHD) = exp(-4.6141 + 0.1545*60) / (1 + exp(-4.6141 + 0.1545*60))
P(CHD) =  0.7946
Therefore, the estimated probability of CHD for a 60-year-old individual is 0.7946, which is closest to choice D (0.7946).

A Medical Researcher Is Interested in Assessing the Probability of Some