 |
|
Pediatric Length of Stay Guidelines and Routine Practice
The Case of Milliman and Robertson
Jeffrey S. Harman, PhD;
Kelly J. Kelleher, MD, MPH
Arch Pediatr Adolesc Med. 2001;155:885-890.
ABSTRACT
| |
Background Guidelines for inpatient length of stay (LOS) have been developed by
Milliman and Robertson (M&R) and are widely applied by health plans. This
study was designed to compare LOS for several pediatric conditions with the
M&R LOS criteria using recent data and to determine if concordance of
actual practice with M&R LOS criteria varied between children and adults.
Design Administrative data from Pennsylvania hospitals from 1996 through 1998
were used to examine LOS for hospital discharges for 12 selected diagnoses
for which M&R published guidelines for children and adults.
Patients Discharge data for all patients discharged from public and private hospitals
in Pennsylvania for which 1 of 12 selected diagnoses were examined.
Main Outcome Measure Length of stay.
Results In Pennsylvania hospitals from 1996 through 1998, pediatric LOS was
divergent for all conditions examined, although not to the extent found in
a previous study examining data from New York State. Of note, median LOS for
some conditions was shorter than M&R LOS criteria. The percentage of pediatric
hospital discharges that exceeded the M&R LOS criteria ranged from 25%
for pneumonia to 84% for meningitis. Adult hospital discharges exceeded M&R
LOS criteria to a greater extent than did pediatric discharges for all conditions
except for sickle cell crisis and meningitis.
Conclusions The M&R LOS criteria were divergent from routine practice for both
children and adults. Greater divergence of adult discharges illustrates the
need to consider comorbid conditions when implementing these guidelines. Thus,
patient care may suffer if guidelines are implemented in an uninformed way.
These findings emphasize the importance of using the best possible science
when producing guidelines such as these.
INTRODUCTION
IN EFFORTS to control costs, many health plans have begun to use clinical
practice guidelines to limit use of health services.1
Although guidelines regarding length of stay (LOS) have been widely disseminated
and adopted, there have been few efforts to examine the validity of these
guidelines, especially for diverse populations.1
It is not known for which patients they are most relevant. Previous studies
have raised concerns regarding the impact of these guidelines on patients,2, 3, 4 especially since many
are not evidence based.
Recently, the LOS guidelines for pediatric conditions published by Milliman
and Robertson (M&R),5 which are the most
widely used by managed care plans throughout the country,6
have come under great scrutiny. The M&R guidelines for pediatric LOS were
developed by faculty members in the Department of Pediatrics at the University
of Texas–Houston Medical School. These guidelines were designed to apply
to routine, uncomplicated cases, but there are reports that they are being
applied to many cases without regard to complications,4
raising concerns about the safety of such guidelines in practice.6 In fact, one physician who was credited as a contributing
author to the guidelines (without his permission) was quoted as saying, "Kids
might die because of these guidelines."7 The
actual impact of these guidelines on processes of care, however, has yet to
be assessed.
In an effort to determine how M&R pediatric LOS guidelines compared
with actual LOS among pediatric patients, Sills et al4
used data from 1995 from the New York Statewide Planning and Research Cooperative
System to examine the percentage of hospital stays and total hospital bed
days that exceeded the M&R LOS criteria for 16 diagnoses. They found pediatric
LOS to be markedly divergent from the M&R LOS criteria, with a significant
proportion of discharges exceeding the criteria. However, it is not clear
from their study whether these findings, which were unique to that area (New
York State), would persist over time in light of increased managed care penetration
and whether they were any less valid for children than adults.
We employed more recent data from a different state (Pennsylvania) to
shed further light on the pediatric M&R LOS criteria. We sought to (1)
determine if pediatric discharges in Pennsylvania exceeded M&R LOS criteria
in similar proportions as those identified by Sills et al,4
who found the median LOS to exceed the M&R LOS criteria for 13 of 16 conditions,
and (2) compare the proportion of pediatric discharges exceeding M&R LOS
criteria to adult discharges exceeding criteria. We hypothesized that the
proportion of pediatric discharges that exceeded the M&R LOS criteria
would be comparable to that found in the investigation by Sills and colleagues.
We also hypothesized that the proportion of discharges that exceeded the adult
M&R LOS criteria for those same conditions in children would be even greater
because adults are more likely to have medical complications8
and thus longer LOS than children.
METHODS
Data from the Pennsylvania Health Care Cost Containment Council hospital
discharge database for the calendar years 1996, 1997, and 1998 were used to
determine LOS for children and adults. The database provides comprehensive
data for each inpatient hospitalization in a nonmilitary acute care hospital
in the state. The study population for this investigation was separated into
2 groups: adults and children. Children were identified as any patient aged
0 to 17 years and adults were identified as any patient aged 18 years or older.
Length of stay is defined in the database using a calendar day approach. For
example, an admission in the evening and a discharge the next morning would
be recorded as a LOS of 2 days, and an admission at 12:01 AM and a discharge
at 11:59 PM on that same calendar day would have a LOS of 1 day. Milliman
and Robertson LOS criteria are based on LOS calculated using this method.5
Patients with a principal diagnosis of appendectomy with complications,
appendectomy without complications, asthma, major but noncritical burn, cellulitis,
diabetic ketoacidosis, gastroenteritis, bacterial meningitis, osteomyelitis,
pneumonia, acute pyelonephritis, and sickle cell crisis were included in the
analysis. These conditions were picked to match the set of conditions analyzed
by Sills et al,4 who chose those conditions
to provide a mix of conditions of high and low severity and both medical and
surgical conditions. Sills and colleagues also examined appendicitis without
abscess, bronchiolitis, croup, and pyloromyotomy, but, because those conditions
were extremely rare in adults in our sample, we chose to not examine those
4 conditions in this analysis. Inpatient hospitalizations with the 12 conditions
were identified using International Classification of Diseases,
Ninth Revision, Clinical Modification (ICD-9-CM)
codes.9 The ICD-9-CM
codes used are identified in Table 1.
|
|
|
|
Table 1. Diagnostic Categorization of Selected Conditions
|
|
|
As in the report by Sills and colleagues, we used the functional M&R
LOS guidelines as opposed to the goal LOS guidelines. The goal LOS guidelines
represent a target for the hospital and are always 1 day shorter than the
functional LOS. We used the pediatric LOS guidelines to assess children's
hospitalizations and adult M&R LOS guidelines to assess adult hospitalization.
There were no differences in the functional LOS guidelines between adults
and children for any of the conditions examined.
Because some patients may have required intensive care and had other
serious complications during their hospital stay, there is the potential for
large outliers with extremely long hospital stays to provide undue weight
to the analysis. Therefore, we chose to eliminate outliers from the analysis.
For our results to be comparable to the results of Sills and colleagues, we
used the same cutoff for eliminating outliers, excluding the 2% longest LOS.
We examined the mean, median, mode, and range of LOS for each of the
12 diagnoses using a computer program (SAS Institute, Cary, NC). We also examined
the frequency distribution of LOS for each condition for adults and children
in relation to the M&R functional LOS guideline, using histograms with
a black bar indicating the M&R LOS guideline. We calculated the percentage
of discharges with LOS exceeding the M&R functional LOS guideline as well
as the percentage of hospital bed days exceeding the guideline. As the data
represent the entire universe of hospital discharges for the 12 conditions
in Pennsylvania, no statistical tests are needed or performed. For each set
of analyses, we additionally examined the 3 years of data separately to determine
if there was an observable time trend and compared LOS for patients with and
without a comorbid condition. Any patient with any secondary diagnosis recorded
in the discharge record was considered to have a comorbid condition, regardless
of the specific secondary diagnosis recorded. In other words, if all of the
secondary diagnosis fields on the discharge record were left blank, the patient
was considered to have no comorbid conditions, and if anything was recorded
in any of the secondary diagnosis fields, the patient was considered to have
a comorbid condition.
RESULTS
CHILDREN
As given in Table 2, for
the 12 conditions examined for children from 1996 through 1998, there were
between 164 cases of appendectomy with complications and 22 060 cases
of asthma. The modal LOS was at or below the M&R functional LOS guidelines
for 10 of the 12 conditions, with modal LOS for major but noncritical burns,
pneumonia, and sickle cell crisis falling below the M&R guidelines. Only
bacterial meningitis and osteomyelitis had modal LOS that exceeded the M&R
guidelines. When the M&R functional LOS guidelines were examined in relation
to the median LOS, 7 of the 12 conditions met the M&R guidelines. The
median LOS was not below the M&R guidelines for any of the 12 conditions
examined. Although only 2 of the 12 conditions had modal LOS that exceeded
the M&R LOS criteria in our data, between 29% and 83% of hospital stays
exceeded the M&R guidelines. The LOS frequency distributions for the 12
conditions (Figure 1) demonstrate
varying proportions of hospitalizations in excess of the M&R LOS guidelines.
The M&R functional LOS guideline is imposed on each plot as a vertical
bar.
|
|
|
|
Table 2. Selected Diagnoses: M&R Functional LOS and LOS Data for
Children From Pennsylvania, 1996-1998*
|
|
|
|
|
|
|
Distribution of length of stay (LOS) for selected diagnoses, Pennsylvania,
1996-1998.
|
|
|
We also examined LOS for each year individually to determine if any
time trend was apparent and examined LOS for children with and without recorded
comorbid conditions. Although the data did not demonstrate a time trend (ie,
the distribution of LOS was essentially the same for each year for all conditions),
63% of children had a comorbid condition. The mean LOS for children with comorbid
conditions was 33% longer than the mean LOS for children without comorbid
conditions. Longer LOS were seen for children with comorbid conditions for
all 12 conditions examined.
To better demonstrate the relationship of M&R guidelines to actual
hospital stays, we calculated the total number of hospital stays that exceeded
the criteria and the total percentage of hospital bed days that exceeded the
M&R LOS criteria for each of the 12 conditions examined (Table 3). Even in the case of pneumonia, for which the LOS comes
closest to the guidelines, 29% of all hospital stays by children were in excess
of the LOS guidelines. For osteomyelitis, sickle cell crisis, and meningitis,
most hospital stays by children exceeded the M&R guidelines, with more
than 80% of hospital stays for meningitis exceeding the guidelines. Total
bed days exceeded the M&R guidelines by at least 20% for all 12 conditions
examined. Furthermore, total bed days exceeded the guidelines by more than
50% for 3 conditions (sickle cell crisis, major but noncritical burn, and
meningitis).
|
|
|
|
Table 3. Proportion of Hospital Stays and Hospital Days That Exceed
the M&R Functional LOS for Children and Adults in Pennsylvania, 1996-1998*
|
|
|
ADULTS
For adult hospital stays, the total number of cases ranged from 398
for meningitis to 132 717 for pneumonia (Table 4). The modal LOS exceeded the M&R guidelines for 6 of
the 12 conditions, and the median LOS exceeded the guidelines for all but
1 condition (acute pyelonephritis). The extent to which hospital stays exceeded
the M&R LOS guidelines for adults is shown in the frequency distribution
curves plotted in Figure 1.
|
|
|
|
Table 4. Selected Diagnoses: M&R Functional LOS and LOS Data for
Adults From Pennsylvania, 1996-1998*
|
|
|
The LOS for each year was examined individually to determine if any
time trend was apparent. The LOS for adults with and without recorded comorbid
conditions was also examined. As was the case with pediatric hospitalizations,
the data did not demonstrate a time trend. However, 92% of adults had a comorbid
condition. Comorbid conditions were much more common with adult hospitalizations
compared with pediatric hospitalizations (92% vs 63%). The mean LOS for adults
with comorbid conditions was 98% longer than the mean LOS for adults without
comorbid conditions. Longer LOS was seen for adults with comorbid conditions
for all 12 conditions examined.
The proportion of adult hospitalizations exceeding the M&R LOS criteria
is greater than that for pediatric hospitalizations for all 12 conditions
examined. The extent to which LOS exceeds the M&R guidelines, especially
relative to LOS for children, can be clearly seen in Table 4. In most cases, the percentage of hospital stays exceeding
the guidelines is far greater for adults, with the largest difference occurring
for hospital stays for pneumonia, for which 75% exceeded the guidelines compared
with 29% for children. The percentage of bed days exceeding M&R LOS criteria
is greater for adults than for children for all 12 diagnoses. The largest
difference occurs with hospital stays for pneumonia, with total bed days exceeding
the M&R guidelines by 51% for adults, whereas total bed days exceeded
the guidelines by 25% for children.
COMMENT
With the growing use of case-rate payments and capitated contracts for
pediatric care, much more attention will be paid to LOS and related guidelines
introduced by M&R,5 among others. While
hospital discharge data from Pennsylvania show that there are a significant
number of bed days that exceed the M&R LOS criteria for pediatric conditions,
it seems that the extent to which LOS exceeds M&R LOS criteria is considerably
less than what was found using discharge data from New York State.4 Sills and coauthors found that 13 of the 16 conditions
examined had median LOS that exceeded the M&R functional LOS guidelines.
In fact, there were several instances when M&R LOS criteria exceeded modal
LOS in our study. There are several reasons why this divergence may have occurred.
One possibility is that there are notable differences in practice styles in
New York and Pennsylvania. Past analyses have shown significant geographical
variations in medical practice for identical conditions.10, 11
It is also possible that there are significant differences in the case mix
between the 2 states. In Pennsylvania, 63% of children had more than 1 diagnosis
recorded. It is possible that an even greater percentage of children in New
York experienced medical complications associated with comorbid conditions.
As LOS were greater for adults and adults were more likely to have comorbid
medical conditions than children, it seems that comorbidity is associated
with increased LOS. The extent of managed care penetration or other characteristics
of the health care market (eg, total hospital beds available) may also account
for differences in observed LOS between the 2 states. Finally, the Pennsylvania
data are for hospitalizations occurring in 1996 through 1998, while the report
by Sills and colleagues used data from 1995. An increase in pressures to contain
costs during this period or other secular changes may explain some of the
observed differences. This last explanation seems unlikely as there was no
observable time trend in the Pennsylvania data between 1996 and 1998.
Although this study found fewer conditions for which the modal and median
LOS exceeded the M&R LOS criteria than did the study by Sills et al,4 between 29% and 83% of hospital stays and between
20% and 64% of bed days exceeded the M&R LOS criteria. Pediatric institutions
would be placed at financial risk if case rates and contracts were based on
M&R criteria without considering the numerous pediatric patients with
hospital stays likely to exceed the M&R LOS criteria. We also observed
several instances in which modal and median LOSs were less than the M&R
LOS criteria. Overall, it seems that M&R LOS criteria are not consistent
with routine practice, with functional M&R LOS criteria being potentially
too short in some cases and potentially too long in others.
There are methodological issues that encourage caution in the interpretation
of our findings. First, the data are drawn from the Pennsylvania Health Care
Cost Containment Council hospital discharge database, an administrative dataset.
As with all administrative datasets, coding of diagnoses is not perfectly
accurate, and coding of diagnoses may be variable across sites. It is not
clear how such a bias would affect results, unless it was not distributed
randomly. Also, such a database cannot adequately describe the outcomes for
patients with early or late hospitalizations such as those with iatrogenic
illness, rehospitalizations, or mortality. To determine a causal relationship
of LOS guidelines on child health, a prospective study would be essential.
Despite these limitations, there are several implications for guideline
creators and users from this study and prior work. First, it is important
for those producing guidelines like M&R to use the best possible science
(eg, evidence for routine practice) in the production of LOS guidelines. The
M&R guidelines are meant to represent best practice,5
but they are likely applied as routine practice.6
It seems that the M&R guidelines may need to be revised to represent routine
practice, with criteria falling both above and below median and modal LOS
for many conditions. It is concerning that for at least 2 conditions (bacterial
meningitis and osteomyelitis), both our study and that by Sills et al4 found the guidelines to be inconsistent with routine
practice from 1995 through 1998.
In addition, those using the guidelines as payers or providers should
understand their purpose—that is, to act as an ideal timeline in the
absence of serious complicating issues or comorbid disorders. In our study,
63% of all children and 92% of adults had at least 1 comorbid diagnosis listed.
Such comorbidity is likely to be at least in part responsible for the numerous
children (more than one fourth) who exceeded guideline-recommended LOS even
for those conditions in which the median did not.
AUTHOR INFORMATION
Accepted for publication March 16, 2001.
The views expressed in this article do not necessarily represent the
views of the University of Pittsburgh.
We gratefully acknowledge the assistance provided by the Marketing Department
of Children's Hospital of Pittsburgh, and we thank Jeffrey Whittle, MD, for
his helpful comments on this manuscript.
From the Child Services Research and Development Program, University
of Pittsburgh School of Medicine, Pittsburgh, Pa.
Corresponding author and reprints: Jeffrey S. Harman, PhD, University
of Pittsburgh School of Medicine, 3811 O'Hara St, Suite 430, Pittsburgh, PA
15213 (e-mail: harmanjs{at}msx.upmc.edu).
REFERENCES
| |
1. Barker K. Seattle firm has sway over hospital stays. Seattle Times. March 14, 2000:1.
2. Rutledge R. An analysis of 25 Milliman and Robertson guidelines for surgery: data-driven
versus consensus-derived clinical practice guidelines. Ann Surgery. 1998;228:579-587.
FULL TEXT
|
ISI
| PUBMED
3. Bachner H, Vinci R, Chessare J. Milliman and Robertson: going in the wrong direction. Pediatrics. 1999;105:858-859.
FREE FULL TEXT
4. Sills MR, Huang ZJ, Shao C, Guagliardo MF, Chamberlain JM, Joseph JG. Pediatric Milliman and Robertson length of stay criteria: are they
realistic? Pediatrics. 2000;105:733-737.
FREE FULL TEXT
5. Health Status Improvement and Management, Pediatric
HSIM: Caring for a Community of Children. Seattle, Wash: Milliman & Robertson Inc; 1998.
6. Sherman N. Hospital stays: too long or too short? ChuMD Web site. Available at: http://www.chumd.com/Medical_News/19-SEP-2000/102747_en.html. Accessed April 11, 2001.
7. Nissimov R. Cost-cutting guide used by HMOs called "dangerous." Houston Chronicle. March 5, 2000: 1.
8. Adams PF, Hendershot GE, Marano MA. Current Estimates from the National Health Interview
Survey, 1996. Hyattsville, Md: National Center for Health Statistics; 1999. Vital
and Health Statistics, Series 10, No. 200.
9. International Classification of Diseases, Ninth Revision,
Clinical Modification. Washington, DC: Public Health Service, US Dept of Health and Human
Services; 1989.
10. Wennberg JE. Understanding geographic variations in health care delivery [editorial]. N Engl J Med. 1999;340:52-53.
FREE FULL TEXT
11. Perrin J. Variations in pediatric hospitalization rates: why do they occur? Pediatr Ann. 1994;23:676-683.
PUBMED
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
How Valid Are Length-of-Stay Guidelines?
JWatch Psychiatry 2001;2001:16-16.
FULL TEXT
How Valid Are Length-of-Stay Guidelines?
JWatch General 2001;2001:8-8.
FULL TEXT
|
