Question 4

Assume the below life table was constructed from following individuals who were diagnosed with slow-progressing form of prostate cancer and decided not to receive treatment of any form. The Kaplan-Meier approach is used to calculate the survival probability. [In regard to rounding in your calculation, choose the answer closest to your calculation result.]

Time in Years	Number at Risk, Nt	Number of Deaths, Dt	Number Censored, Ct	Survival Probability
0	20			1
1	20	3
2	17		1
3	16	2	1

What was the survival probability of Year 2?

Group of answer choices

a) 0.85

b) 0.80

c) 1.0

d) hard to determine.

Question 5

Assume the below life table was constructed from following individuals who were diagnosed with slow-progressing form of prostate cancer and decided not to receive treatment of any form. The Kaplan-Meier approach is used to calculate the survival probability. [In regard to rounding in your calculation, choose the answer closest to your calculation result.]

Time in Years	Number at Risk, Nt	Number of Deaths, Dt	Number Censored, Ct	Survival Probability
0	20			1
1	20	3
2	17		1
3	16	2	1

What was the survival probability of Year 3?

Group of answer choices

a) 0.85

b) 0.80

c) 0.69

d) 0.74

Question 6

A Cox regression model is estimating relating time to psychiatric hospitalization in patients with severe mental illness. The risk factors include age, sex, prior hospitalization for mental illness, and an indicator of bipolar disorder. The parameter estimates and significance levels for the Cox regression model are shown below.

Predictor Parameter Estimate (b) P value

Age, years 0.0045 0.5647

Sex (0=female, 1=male) -0.4841 0.0341

Prior hospitalization

(0=no, 1=yes) 0.3726 0.0178

Bipolar disorder (0=no, 1=yes) 0.7561 0.0042

At the significance level of 0.05, which of the following statements about the associations between these predictors and time-to-psychiatric hospitalization is right?

Group of answer choices

a) All four risk factors, age, sex, prior hospitalization for mental illness, and an indicator of bipolar disorder were significantly associated with time-to-psychiatric hospitalization.

b) Only the indicator of bipolar disorder was significantly associated with time-to-psychiatric hospitalization.

c) Sex, prior hospitalization for mental illness, and an indicator of bipolar disorder were significantly associated with time-to-psychiatric hospitalization.

d) None of the above answers is right.

Question 7

A Cox regression model is estimating relating time to psychiatric hospitalization in patients with severe mental illness. The risk factors include age, sex, prior hospitalization for mental illness, and an indicator of bipolar disorder. The parameter estimates and significance levels for the Cox regression model are shown below.

Predictor Parameter Estimate (b) P value

Age, years 0.0045 0.5647

Sex (0=female, 1=male) -0.4841 0.0341

Prior hospitalization

(0=no, 1=yes) 0.3726 0.0178

Bipolar disorder (0=no, 1=yes) 0.7561 0.0042

From these results, are men or women more likely to be hospitalized if all factors remain the same? [Of note, you need to think about the predicted hazard ratio.]

Group of answer choices

a) Men

b) Women

c) Men and women are "equal" in this issue.

d) Not enough information to make a decision.