HCAI 5220
Fall 2012
Ed Schumacher
Homework 1
Due (on or about) September 4
1. In the Homework1.xls file the worksheet titled “Market Share” contains patient level data
for discharges across all hospitals in San Antonio over the 2009 to 2011 period.
a. Create a pivot table that shows the overall market share by system. The table should
show both total discharges and market share (value field settings, show values as %of
grand total). What system has the largest market share?
b. Next show market share by system by hospital. Show total discharges and
proportion of hospital to system discharges. (value field settings, show values as
% of Parent Row Total). Filter out the “Out of Area” patients. What is
CHRISTUS’ largest hospital in terms of admissions?
c. Show the number of admission, average LOS and the standard deviation of LOS
by 15 year age groups. For which age group is the variation in length of stay
largest?
d. Create a pivot table that shows the market share by service line(DRG Product
Line) by system, sort the product lines from largest to smallest and sort within
each product line as well to show the largest to smallest system. Who is the
market leader in neonatology? What percent of the market do they have?
2. In the Homework 1.XLS file the worksheet titled “Physician Admissions” contains a
sample of data from a group of physicians who see patients in your hospital. You would
like to understand which doctors are admitting more than the norm and which are
admitting less than the norm.
a. What is the average number of visits and admissions?
b. Calculate proportion of each doctor’s patients that he/she ends up admitting into
the hospital.
c. Calculate the overall proportion of patients that are admitted.
d. Use the vlookup command in Excel to pull the number of visits by Dr. Green.
e. Use the vlookup command to pull the percentage of admissions for Dr.
Henderson.
f. Construct a 95% confidence interval for each doctor of their “true” admission
rate.
g. Construct a graph that shows each doctor’s admission rate (in ascending order),
the minimum and maximum of the confidence interval, as well as the overall
proportion of admissions. (Write the command for the minimum to be zero if the
calculated value is negative).
h. Which doctors can you say are above and below the norm? Explain.
3. (the simple version) At BigCounty Community Hospital the administrator has
implemented multiple innovations to attempt to reduce overall length of stay in the public
hospital. You have been asked to assess if these efforts have been successful. Suppose
we know that in 2005 the population parameters were as follows:
DRG
124
125
127
202
316
370
371
430
462
494
Overall
LOS
5.69
3.15
6.34
6.48
5.36
5.30
3.37
6.88
13.68
2.92
5.88
Suppose we take a sample of admissions in 2011 and obtain the following:
Average
DRG
124
125
127
202
316
370
371
430
462
494
Overall
Standard
Deviation
Sample Size
5.34
4.20
132
3.01
2.84
82
4.92
3.08
118
6.04
4.70
142
5.54
3.95
152
5.08
4.86
138
2.76
1.57
290
6.75
2.94
264
14.73
8.59
66
2.33
1.20
101
5.20
4.53
1485
a. Is there evidence that overall LOS has changed over this period?
b. Is there evidence that LOS changed within each DRG? Provide a summary table
of the results. (test statistic, pvalue, and conclusion).
4. (a little more complicated) At BigCounty Community Hospital the administrator has
implemented multiple innovations to attempt to reduce overall length of stay in the public
hospital. You have been asked to assess if these efforts have been successful. In the
Homework1.xls file the worksheet “Hospital Data 05 11” contains data on a sample of
patients for 2005 and 2011. The sample includes the top 5 DRGs over the period.
a. What is the overall average LOS in 2005 and in 2011? Is this difference
significant.
b.What is the average LOS by DRG in 2005 and in 2011. Is there evidence that
LOS has changed within each of these 5 DRGs? Create a table that displays the
average and standard deviation for each year as well as the z statistic and pvalue.
Then summarize the results.
5.You are next asked to examine what is happening with source of admission and payer
status at BigCounty Hospital.
a. What is the proportion of admissions coming from the EMERGENCY CENTER
in 2011 and in 2005? Has there been a significant change in this proportion?
b.What has happened to the proportion of “Self Pay” patients between 2005 and
2011?
c. Is there evidence of a relationship between source of admission and payer status
(combining years)? Explain