HCM530 Case Study 4- Risk Adjustment with Multivariate
HCM530 Case Study 4- Risk Adjustment with Multivariate
Subject: General Questions / General General Questions
Question
HCM530
Case Study 4
Risk Adjustment with Multivariate Techniques (New York)
The state of New York (http://www.health.state.ny.us/nysdoh/consumer/heart/1996-98cabg.pdf) has
reported risk adjusted mortality statistics for coronary artery bypass graft surgery (CABG) for a number
of years, as discussed earlier in the text. New York uses the second major approach to risk adjustment, a
multivariate model. Such models control for different kinds of patient characteristics that are likely to
influence mortality. Table 4.1 reports the multivariate model used to calculate this risk-adjusted
measure. (Textbook Case Study 6.4)
Table 4.1: Multivariable risk factor equation for CABG hospital deaths in New York State in 1998.
Logistic Regression
Patient Risk Factor Prevalence (%) Coefficient P-Value Odds Ratio Demographics
Age
Female Gender ….
28.92 0.0671
0.5105 <0.0001
<0.0001 1.069
1.666 Hemodynamic State
Unstable
Shock 1.32
0.45 1.0423
1.8458 <0.0001
<0.0001 2.836
6.333 30.91
2.228
15.97 0.3607
0.9759
0.5012 0.0010
<0.0001
<0.0001 1.434
2.654
1.651 1.89
1.89
0.10 0.9213
0.9213
3.0535 <0.0001
<0.0001
<0.0001 2.513
5.688
21.190 Severity of Atherosclerotic Process
Aortoiliac Disease
Stroke 5.42
7.01 0.5481
0.4775 0.0006
0.0016 1.730
1.621 Ventricular Function
Ejection Fraction <20
Ejection Fraction 20-29
Ejection Fraction 30-39 1.77
7.40
14.49 1.4235
0.8183
0.6186 <0.0001
<0.0001
<0.0001 4.151
2.267
1.856 Previous Open Heart Operations 5.98 0.6800 <0.0001 1.974 Comorbidities
Diabetes
Malignant Ventricular Arrhythmia
COPD
Renal Failure (no dialysis),
Creatinine > 2.5
Renal Failure requiring Dialysis
Hepatic Failure Intercept = -9.4988
C Statistic = 0.793 Case Questions: Answer the case questions, with research from your book, CDC, NIH and other quality
sources to determine answers and solutions. You are to write a 2-3 page paper in APA formatting that
addresses the following questions. Note: A minimum of two references should be used, which should
include your textbook and the CDC, and others that support your responses in your paper. This is a
paper, so your answer should not be numbered, but rather it should use titles and subtitles.
1. Which factors are supposedly related to CABG morality?
2. Which factors are the most strongly related to CABG mortality?
3. How could one derive an expected mortality rate from the multivariate model?
