|
RESULTS
The University of Michigan Medical Center discharged 29,036
patients during fiscal year 1998. Table 1 provides descriptive
statistics on all surviving patients discharged during this period
who had LOS of 4 days or more and were not discharged against
medical advice (n = 12,365). Patients who fit this description
had mean and median LOS of 10.5 days and 7 days, respectively.
Mean (± SEM) and median total costs per case were $17,734
± $229 and $10,289, respectively, and the mean (±
SEM) and median variable direct costs of the last full day before
discharge were $420 ± $7 and $310. These results show
that hospital-wide, the last full day before discharge represented
9.5% of the mean 10.5-day LOS, and yet only 2.4% of the total
cost of care can be identified specifically with this interval.
Table 1 also stratifies patients by LOS. In all cases, last-day
resource consumption was remarkably light; mean variable direct
costs incurred on that day were $458 or less. For LOS of 4 days,
for example, the last full day represented 25% of the total LOS,
and yet only 6.8% of the total cost of care was attributable
to this period.
Table 1. Costs for Surviving Patients for the Hospital
at Large
|
|
LOS |
n |
Mean total cost ($) |
Last-day VDC ($) |
Last-day VDC as percentage of mean total cost (%) |
|
|
4 |
2,614 |
6,782 ± 96 |
458 ± 20 |
6.8 |
|
5 |
1,820 |
8,453 ± 154 |
445 ± 24 |
5.3 |
|
6 |
1,284 |
9,632 ± 185 |
373 ± 9 |
3.9 |
|
7 |
1,130 |
11,131 ± 211 |
421 ± 28 |
3.8 |
|
8-14 |
3,365 |
16,419 ± 182 |
406 ± 14 |
2.5 |
|
>15 |
2,152 |
49,246 ± 999 |
402 ± 7 |
0.8 |
|
All patients LOS > 4 |
12,365 |
17,734 ± 229 |
420 ± 7 |
2.4 |
|
Data are presented as mean ± SEM or %.
LOS, length of stay; VDC, variable direct cost.
Table 2 examines subgroups of this population who had major
surgery (n = 4,163) and those who did not (n = 7,195). The purpose
of this stratification is to determine whether the results in
Table 1 might be driven primarily by patients with large up-front
expenses followed by long periods of convalescence (with low
attendant resource costs). The left-hand columns of Table 2 describe
patients who incurred $2,000 or more in surgical costs during
their hospital stays; the right-hand columns include those patients
who incurred less than $1,000 in such costs. There were relatively
few patients (n = 1,007) who had total surgical costs in the
$1,000 to $2,000 range, and so this group was omitted to ensure
a stark distinction between the categories. By design, this stratification
isolates patients who likely had large expenditures early in
their hospital stays and juxtaposes them against lower-cost patients
who could conceivably consume hospital resources more uniformly
over the entire LOS. As one might expect, cases involving major
surgery entailed higher mean total costs. The $36 difference
in the last-day variable direct costs ($396 for patients with
major surgery and $432 for patients without major surgery), although
statistically significant (p = 0.020 by the two-tailed Student's
t-test), is small. Consequently, variable direct costs
incurred on the last full day before discharge constituted only
1.5% of the $26,547 average total cost for patients having major
surgery, compared with 3.4% of the $12,631 average total cost
for patients not having major surgery. The stratification by
LOS in Table 2 reinforces the results in Table 1. What is striking
is that last-day costs as a percentage of total costs are remarkably
small even for patients who undergo no major surgery and have
LOS of 4 or 5 days.
Table 2. Comparison of Patients With Major Surgery and
Patients Without Major Surgery
|
|
|
Surviving patients with major surgery (patients
incurring >$2,000 in surgical costs) |
Surviving patients with no major surgery (patients
incurring <$1,000 in surgical costs) |
|
|
|
|
|
LOS |
n |
Mean total cost ($) |
Last-day VDC ($) |
Last-day VDC as percent of mean total cost
(%) |
n |
Mean total cost ($) |
Last-day VDC ($) |
Last-day VDC as percent of mean total cost
(%) |
|
|
4 |
681 |
10,737 ± 249 |
461 ± 54 |
4.3 |
1,756 |
5,316 ± 74 |
464 ± 21 |
8.7 |
|
5 |
522 |
13,055 ± 395 |
410 ± 52 |
3.1 |
1,137 |
6,596 ± 122 |
466 ± 28 |
7.1 |
|
6 |
394 |
13,934 ± 414 |
348 ± 12 |
2.5 |
798 |
7,545 ± 154 |
388 ± 13 |
5.1 |
|
7 |
381 |
14,493 ± 418 |
358 ± 23 |
2.5 |
670 |
9,287 ± 209 |
429 ± 24 |
4.6 |
|
8-14 |
1,274 |
20,835 ± 330 |
379 ± 16 |
1.8 |
1,800 |
16,351 ± 199 |
421 ± 24 |
2.6 |
|
>15 |
911 |
64,552 ± 1,979 |
399 ± 13 |
0.6 |
1,034 |
36,532 ± 861 |
397 ± 7 |
1.1 |
|
All patients LOS >4 |
4,163 |
26,547 ± 552 |
396 ± 13 |
1.5 |
7,195 |
12,631 ± 184 |
432 ± 10 |
3.4 |
|
Data are presented as mean ± SEM
or %.
LOS, length of stay; VDC, variable direct cost.
To gain perspective and detail, we conducted a subgroup analysis
on all patients discharged from our level I trauma center during
this period (n = 665). Table 3 provides descriptive statistics
on this population. The table indicates that the $9,177 mean
variable direct cost per patient is only 42% of the mean total
cost per patient of $22,067. The remaining 58% is hospital overhead.
The initial analysis of the population revealed that 46 patients
died (6.9%) and 4 were discharged against medical advice (0.6%).
There were 287 patients (43.2%) who spent at least 1 day in the
ICU and 468 patients (70.4%) who stayed in the hospital 3 days
or more. For the entire population, mean and median LOS were
8.3 days and 5 days, respectively. Total variable direct costs
were $6,102,551 and total costs were $14,674,355. In aggregate,
19.4% of the total variable direct costs were incurred on the
first day of hospitalization, 11.1% were incurred on the second
day, and 7.7% were assessed on the third day. On our trauma service,
57.6% of all variable direct costs were incurred within the patients'
first 7 days of stay. The mean and median variable direct costs
and total costs per patient for the first 3 days are identified
in Table 4.
Table 3. Descriptive Statistics for the Trauma Service
in Fiscal Year 1998 (n=665)
|
|
Characteristic |
Mean ± SEM |
Median |
|
|
Age (y) |
39.2 ± 0.8 |
37 |
|
LOS (d) |
8.3 ± 0.4 |
5 |
|
ICU days |
2.6 ± 0.2 |
0 |
|
Total cost per patient ($) |
22,067 ± 1,416 |
8,925 |
|
Variable direct cost per patient ($) |
9,177 ± 645 |
3,147 |
|
LOS, length of stay.
Table 4. Variable Direct Costs Per Day for the First 3
Days of Trauma Hospitalization
|
|
Variable direct costs |
n |
Mean ± SEM ($) |
Median ($) |
|
|
First day of stay |
665 |
1,783 ± 78 |
1,246 |
|
Second day of stay |
559 |
1,216 ± 75 |
576 |
|
Third day of stay |
468 |
1,008 ± 64 |
508 |
|
Table 5 identifies the same figures for the last 3 days of
these patients' hospital stays. A comparison of the two tables
reveals that these last 3 days are much less expensive than the
first few days. For example, the median variable direct cost
of $1,246 on the first day of admission is more than four times
the $304 median variable direct cost on the day of discharge.
Table 5. Variable Direct Costs Per Day for the Last 3 Days
of Trauma Hospitalization
|
|
Variable direct costs |
n |
Mean ± SEM ($) |
Median ($) |
|
|
2 days before discharge |
468 |
712 ± 39 |
385 |
|
Day before discharge |
568 |
653 ± 37 |
323 |
|
Day of discharge |
665 |
614 ± 37 |
304 |
|
For various reasons, the $614 mean variable direct cost incurred
on the discharge day overstates the true cost of the last day
of a patient's hospital stay. First, this figure includes the
unusually high costs incurred by the 46 nonsurvivors in the population.
The left side of Table 6 omits these 46 patients, along with
4 patients who were discharged against medical advice. Second,
this $614 figure includes 242 patients who stayed in the hospital
for 3 days or less. For these patients, the costs incurred in
the last 3 days are also costs incurred in the first 3 days.
To isolate the costs incurred at the end of the patients' hospital
stays, the right-hand side of Table 6 also omits these 242 patients
(along with the 50 patients who were omitted in the left-side
calculations). These figures identify the end-of-stay variable
direct costs of what one might consider a "representative''
surviving trauma-service patient in fiscal year 1998. The mean
variable direct costs of the last 3 days of stay were $487, $396,
and $333, and the median costs were $334, $278, and $257, respectively.
Table 6. End-of-Stay Variable Direct Costs Per Day for
Trauma Subgroups
|
|
|
|
|
|
|
|
|
Excluding nonsurvivors and patients discharged
against medical advice |
Also excluding patients with LOS > 3d
(n = 373) |
|
|
|
|
|
Outcomes |
n |
Mean
± SEM |
Median |
Mean
± SEM |
Median |
|
|
LOS (d) |
615 |
8.3 ± 0.4 |
5 |
12.4 ± 0.6 |
8 |
|
ICU d |
615 |
2.1 ± 0.2 |
0 |
3.4 ± 0.3 |
1 |
|
VDC 2 d before discharge ($) |
435 |
591 ± 30 |
362 |
487 ± 24 |
334 |
|
VDC 1 d before discharge ($) |
532 |
535 ± 28 |
306 |
396 ± 21 |
278 |
|
VDC on d of discharge ($) |
615 |
471 ± 21 |
286 |
333 ± 13 |
257 |
|
LOS, length of stay; VDC, variable direct cost.
Further refinement is possible by stratifying this population.
Table 7 represents patients who spent at least 3 days in the
ICU and 7 days in the hospital. These are the most seriously
injured patients, and the table shows that these patients were
costly to care for even after they were discharged from the ICU.
The first 3 post-ICU days had mean variable direct costs of $1,017,
$1,054, and $894, respectively. Yet by the time they were discharged,
these patients' variable direct costs of care fell below $500
per day, as was the case for all other subgroups analyzed.
Table 7. Surviving Trauma Patients with 3 or More ICU Days
and Length of Stay of 7 Days or More
|
|
Outcomes |
n |
Mean ± SEM |
Median |
|
|
LOS (d) |
105 |
22.3 ± 1.5 |
18 |
|
VDC on first post-ICU day ($) |
105 |
1,017 ± 58 |
975 |
|
VDC on second post-ICU day ($) |
102 |
1,054 ± 145 |
786 |
|
VDC on third post-ICU day ($) |
98 |
894 ± 86 |
644 |
|
VDC 2 days before discharge ($) |
105 |
609 ± 55 |
443 |
|
VDC 1 day before discharge ($) |
105 |
487 ± 37 |
365 |
|
VDC on day of discharge ($) |
105 |
404 ± 28 |
321 |
|
LOS, length of stay; VDC, variable direct cost.
Introduction
| Methods
| Results | Discussion
| References
JACS |
