Reference no: EM13253172
1. A study is conducted to estimate survival in patients following kidney transplant. Key factors that adversely affect success of the transplant include advanced age and diabetes. This study involves 25 participants who are 65 years of age and older and all have diabetes. Following transplant, each participant is followed for up to 10 years. The following are times to death, in years, or the time to last contact (at which time the participant was known to be alive).
Deaths: 1.2, 2.5, 4.3, 5.6, 6.7, 7.3 and 8.1 years
Alive: 3.4, 4.1, 4.2, 5.7, 5.9, 6.3, 6.4, 6.5, 7.3, 8.2, 8.6, 8.9, 9.4, 9.5, 10, 10, 10, and 10 years
Use the life table approach to estimate the survival function. Use years intervals of
0-2; 2-4;
Complete the table below.
Interval
in
Years Number At Risk During Interval,
Nt Average Number At Risk During Interval,
Nt* =Nt-Ct /2 Number of Deaths During Interval,
Dt Lost to Follow-Up,
Ct Proportion Dying
qt = Dt/Nt* Proportion Surviving
pt = 1-qt
Survival Probability
St = pt*St-1
0-2
2-4
4-6
6-8
8-10
Use the Kaplan-Meier approach to estimate the survival function.
Complete the table below
Time, Years Number at Risk
Nt Number of Deaths
Dt Number Censored
Ct Survival Probability
St+1 = St*((Nt-Dt)/Nt)
0 25
1.2
2.5
3.4
4.1
4.2
4.3
5.6
5.7
5.9
6.3
6.4
6.5
6.7
7.3
8.1
8.2
8.6
8.9
9.4
9.5
10.0
Referring to the graph above:
What is the probability of surviving 6.5 years?
A. None
B. 0.85
C. 0.60
D. 0.90
Patients have an 85% chance of surviving how many years?
A. 6.0
B. 4.25
C. 3.2
D. 5.5
2. 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.
New Drug Currently Available Drug
Hypertension Free of Hypertension Hypertension Free of Hypertension
7 8 6 8
8 8 7 9
10 8 9 11
9 10 11
11 11 12
12
12
Estimate the survival (time to progression to hypertension) functions for each treatment group using the Kaplan-Meier approach.
New Drug
Complete the table below.
Time, Months Number at Risk
Nt Number of Events (Hypertension)
Dt Number Censored
Ct Survival Probability
St+1 = St*((Nt-Dt)/Nt)
0 10
7
8
9
10
11
12
Currently Available Drug
Complete the table below.
Time, Weeks Number at Risk
Nt Number of Events (Hypertension)
Dt Number Censored
Ct Survival Probability
St+1 = St*((Nt-Dt)/Nt)
0 10
6
7
8
9
10
11
12
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
Find the work done on the ball by air resistance
: A basketball player makes a jump shot. The 0.606 kg ball is released at a height of 2.18 m above the floor with a speed of 7.26 m/s. What is the work done on the ball by air resistance, a nonconservative force
|
Indicate how the strategy should be implemented
: From the e-Activity, identify the company, the accounting impropriety or illegality, how it was detected, the outcome, and propose a strategy that might have prevented the situation. Indicate how the strategy should be implemented.
|
Find the minimal sum and distinguished 1-cell using k-map
: Find the minimal sum and distinguished 1-cell using Karnaugh Maps for the following functions, also state essential prime implicants (if any) and which are non-essential prime implicants (if any) a. F = fA,B,C,D (2,,4,6,7,12,13,14,15)
|
What is the most efficient way in which a home improvement
: What is the most efficient way in which a home improvement company such as Lowes or Home Depot could improve your shopping experience.
|
Meier approach to estimate the survival function
: Use the Kaplan-Meier approach to estimate the survival function.
|
Support your recommendation with data from your analysis
: Recommend which company you consider as the better investment for your client and how you will present your recommendation. Support your recommendation with data from your analysis.
|
What is the break-even point in units
: Marty Quinn has business packing software in Laredo, TX . His annual fixed cost is $10,322.09, direct labor is $3.32 per package, and material is $4.20 per package. The selling price will be $12.9 per package. i) What is the break-even point in un..
|
Determine the change in the length of the rope
: A 57-kg water skier is being pulled by a nylon tow rope that is attached to a boat. The unstretched length of the rope is 11 m, What is the change in the length of the rope when the skier has an acceleration whose magnitude is 0.90 m/s2
|
Determine the probability of the chosen number
: Generate 1000 random variables that are normally distributed with mean 0 and standard deviation 50. Pick a number at random out of these random variables. Hint: Leverage the capabilities of the for loop to simplify the code.
|