# Assignment

Question 1: In the following questions assume that we have followed two clinicians, Smith and Jones, and constructed the decision trees in Figure 1. Atoosa's Video►

Figure 1:  Practice Patterns of Dr. Jones and Smith

• What is the expected length of stay for each of the clinicians?
• What is the expected length of stay for Dr. Smith if he were to take care of patients of Dr. Jones?
• What is the expected length of stay for Dr. Jones if he were to take of patients of Dr. Smith?

Question 2: The following table shows the observed and expected length of stay for 30 patients.  Data►

• Use paired comparison of means to test that the expected and observed length of stay are the same.

• Assuming normal distribution of the length of stay, use risk-adjusted control chart to plot the data.  Make sure that control limits are derived from the expected values and observations are contrasted to these limits.  This analysis can be done using Tukey or XmR and you need to select which chart produces tighter control limits.

The conclusions you arrive at based on (a) paired comparison of expected and observed length of stay and (b) the risk-adjusted control charts should be the same if in both situations we were calculating the control limits from the same number of cases.  Are they?

 t-Test: Paired Two Sample for Means Expected Observed Mean 4.8 3.9 Variance 2.10 0.64 Observations 30 30 Pearson Correlation 0.10 Hypothesized Mean Difference 0 df 29 t Stat 3.11 P(T<=t) one-tail 0.00 t Critical one-tail 1.70 P(T<=t) two-tail 0.00 t Critical two-tail 2.05

# Presentations

How to provide feedback to clinicians Slides►  Listen►

Narrated lecture requires use of Flash►

# More

1. Practice profiling PubMed►
2. Importance of risk adjustment in measuring performance in primary care PubMed►

Prepared by Farrokh Alemi, Ph.D. This page is part of the course on Statistical Process Improvement