333 lines
20 KiB
Plaintext
333 lines
20 KiB
Plaintext
|
||
Neural Nets Improve Hospital Treatment Quality and Reduce Expenses
|
||
|
||
June 9, 1990
|
||
by Jeannette Lawrence
|
||
|
||
|
||
A new hospital information and patient prediction system has improved
|
||
the quality of care, reduced the death rates and saved millions of
|
||
dollars in resources at Anderson Memorial Hospital in South Carolina.
|
||
The CRTS/QURI system uses neural networks trained with BrainMaker (from
|
||
California Scientific Software) to predict the severity of illness and
|
||
use of hospital resources. Developed by Steven Epstein, Director of
|
||
Systems Development and Data Research, the CRTS/QURI system's goal is to
|
||
provide educational information and feedback to physicians and others to
|
||
improve resource efficiency and patient care quality.
|
||
|
||
The first study showed that the program was directly responsible for
|
||
saving half a million dollars in the first 15 months even though the
|
||
program only included half of the physicians and three diagnoses. Since
|
||
then, the number of diagnoses and physicians included in the program
|
||
have increased. The quality of care has improved such that there are
|
||
fewer deaths, fewer complications, and a lowered readmission rate.
|
||
Expenses have been reduced by fewer unnecessary tests and procedures,
|
||
lowered length of stays, and procedural changes.
|
||
|
||
Over the past five months the hospital's accounting department has
|
||
reported a savings in the millions of dollars, although it is difficult
|
||
to say exactly how much of this is directly due to CRTS/QURI. According
|
||
to Epstein, "The hospital may now be experiencing a "spillover effect"
|
||
of new physician knowledge and behavior into areas not initially
|
||
targeted by the CRTS/QURI system." The reported success has motivated
|
||
several other hospitals to join in the program and has provided the
|
||
impetus to begin a quality program with the state of South Carolina.
|
||
|
||
At the core of this new system lies several back-propagation neural
|
||
networks which were designed using the BrainMaker program on a PC.
|
||
Individually trained neural networks learn how to classify and predict
|
||
the severity of illness for particular diagnoses so that quality and
|
||
cost issues can be addressed fairly. After attempts to use regression
|
||
analysis to predict severity levels for several diagnoses failed,
|
||
Epstein turned to the BrainMaker program for a new approach and taught
|
||
his neural networks to classify and predict severity with 95% accuracy.
|
||
The neural networks are also used to predict the mode of discharge -
|
||
routine through death - for particular diagnoses.
|
||
|
||
Without these neural networks, the system could not automatically
|
||
compare cases with the same diagnoses and like severity levels. Most
|
||
commercially available severity programs provide mortality as the only
|
||
measure of quality. Physicians typically reject systems which only
|
||
compare costs or mortality rates as being too crude or unfair.
|
||
|
||
In order to provide more meaningful feedback and valid comparisons
|
||
within homogeneous groups of patients, the CRTS Acuity Indexing Scale
|
||
was developed. Patients are rated for the severity of illness on a
|
||
scale from -3 to +3. Training information is based upon the length of
|
||
stay in the hospital which has a direct relationship to the severity of
|
||
the illness (acuity). When making predictions, a -3 patient is expected
|
||
to require the least hospitalization and resources, a 0 patient average,
|
||
and a +3 patient the most. Cases which are run through the trained
|
||
network can then be indexed in a database by their severity level and
|
||
retrieved by such for comparisons.
|
||
|
||
|
||
|
||
Neural Network Designs
|
||
|
||
The neural network was trained to make the severity prediction using
|
||
variables of seven major types: diagnosis, complications/comorbity, body
|
||
systems involved (e.g., cardiac and respiratory), procedure codes and
|
||
their relationships (surgical or nonsurgical), general health indicators
|
||
(smoking, obesity, anemia, etc.), patient demographics (race, age, sex,
|
||
etc.), and admission category.
|
||
|
||
Using a neural network to learn the effects that these variables have on
|
||
the severity of illness takes the CRTS/QURI a step beyond the other
|
||
programs available for indexing severity of illness. With a neural
|
||
network, it is possible to discover relationships that were previously
|
||
unrecognized. There is no need to define how the variables are related
|
||
to the output, the neural network learns it on its own. BrainMaker
|
||
provides the ability to view how any one of these variables effects the
|
||
output of the network. Using BrainMaker's neuron graphics any input can
|
||
be varied over some range and the effect that this has can be plotted.
|
||
|
||
The neural network learns (just as profession literature states) that
|
||
elderly patients with the same diagnosis require more care than younger
|
||
patients and that patients with family support tend to require shorter
|
||
hospital stays. Unlike traditional programs, there is no need to
|
||
translate premises like these into program statements or formulas. The
|
||
neural network learns these and other associations by viewing case after
|
||
case until it picks up the patterns using the back-propagation
|
||
algorithm.
|
||
|
||
Three years of patient data was chosen for training. There were
|
||
approximately 80,000 patients to choose from and 473 primary diagnoses.
|
||
The cases were pre-selected with multiple regression techniques to
|
||
eliminate outliers so that no "bizarre" cases were used for training the
|
||
neural network. For a given diagnosis, about 400 to 1000 cases were
|
||
used to train on.
|
||
|
||
Data was collected from automated medical records, the QURI program
|
||
(explained in the next section), and Federally required files for
|
||
Medicare patients. These were downloaded and read into the CRTS
|
||
database which is in an rBase format on a PC. The selected training
|
||
data was output from the rBase file as a dBase file because there is a
|
||
direct link to BrainMaker this way. The dBase file was read by
|
||
BrainMaker's preprocessor called NetMaker which automatically translates
|
||
the data into neural network files for BrainMaker. These files define
|
||
the network architecture, the screen display, and the training and
|
||
testing data in BrainMaker format. After these automatic conversions
|
||
were done, the neural network was trained in BrainMaker.
|
||
|
||
During the initial neural network design phase, decisions had to be made
|
||
as to which variables were important so that unnecessary data collection
|
||
could be avoided. In order to help make this decision, Epstein used
|
||
BrainMaker's Hinton diagrams to see which inputs affected the trained
|
||
network the most. These diagrams present a picture of connection
|
||
strengths (weights) at the hidden and output layers. A neuron which
|
||
connects to all the neurons in the next layer with the same strength
|
||
transmits no useful information.
|
||
|
||
Two neural networks for each diagnosis were trained - one to predict the
|
||
use of resources and the other to predict the type of discharge. For a
|
||
single diagnosis network, there are 26 input variables and one output
|
||
variable. BrainMaker trained in about 4 hours using a NorthGate 386
|
||
running at 33 MHz. Epstein began training with a .1 tolerance which
|
||
means every prediction for every case must be 90% accurate. Then he
|
||
lowered the tolerance to .085 and eventually stopped with the network
|
||
trained at .05 training tolerance (95% accurate). Then a test set of
|
||
cases was run through. The BrainMaker program has built-in testing
|
||
capability. In addition, Epstein and Jones verified the results of the
|
||
network before using the network to categorize patients and make
|
||
predictions.
|
||
|
||
|
||
The CRTS/QURI System
|
||
|
||
Once the cases are indexed according to severity level, the CRTS
|
||
(Computerized Resource Tracking System) can be used to provide
|
||
educational feedback to physicians concerning quality care issues and
|
||
the use of hospital resources. CRTS combines computer software which
|
||
produces automated graphs, reports and summaries along with a
|
||
comprehensive educational format. An artificial intelligence program,
|
||
VP Expert, is used to generate individual physician's reports.
|
||
|
||
The CRTS program is more affordable than other indexing systems in that
|
||
no additional chart abstracting is necessary. The majority of
|
||
information is retrieved from the hospital's "mainframe" computer.
|
||
Information sources include the medical records abstract, UB82 files
|
||
(medicare), and QURI data.
|
||
|
||
The "QURI" portion of the CRTS/QURI system is an integrated data
|
||
collection and reporting program. Epstein developed this stand-alone
|
||
menu-driven, user-friendly software program which provides computer
|
||
integration for departments which provide additional data for quality
|
||
analysis.
|
||
|
||
QURI stands for Quality assurance, Utilization review, Risk management
|
||
and Infection control. Quality Assurance monitors various criteria for
|
||
specific procedures and diseases. Utilization Review monitors resource
|
||
related items such as admission justification and intensity of services.
|
||
Risk Management determines things that put a patient or hospital at risk
|
||
(such as a fall out of bed), and Infection Control monitors infections
|
||
acquired during the hospital stay.
|
||
|
||
CRTS is used for evaluation at various levels. At the hospital level,
|
||
comparisons are made to data published by the profession to identify
|
||
areas of major concern for the hospital. Individual diagnoses that show
|
||
problems of quality and/or finance are identified. At the physician
|
||
specialty group level, treatment for various severity levels of a
|
||
diagnosis are discussed. At the individual physician level, one page of
|
||
written summary and five pages of comparative graphs are provided. This
|
||
confidential report shows how a physician's patients compared to the
|
||
hospital wide average for a particular diagnosis. Comparisons are
|
||
provided for areas such as the types of procedures used, ancillary
|
||
services used, patient demographics, infection rate, complications,
|
||
readmissions, and predicted (versus actual) illness severity level,
|
||
charges, and mortality rate. A summary of problem areas and a list of
|
||
suggestions are also included in the report.
|
||
|
||
CRTS is implemented in two primary modules 1) collecting and analyzing
|
||
the data with neural networks, and 2) conducting the physicians'
|
||
education program. Epstein, who originally designed the system for his
|
||
dissertation, is in charge of the data-related portions. Dr. Fred
|
||
Jones, Executive Vice President of Medical Affairs at Anderson Memorial,
|
||
sets up physician education (feedback) programs, trains them in the use
|
||
of system, and verifies trained neural networks results.
|
||
|
||
|
||
Physician Response
|
||
|
||
Getting the physicians to accept the new system was no easy task.
|
||
"Initially some of the physicians must have thought the program was a
|
||
Communist Plot. One even stood up in an early meeting to declare the
|
||
whole thing 'crap'," says Epstein. He explains that Jones has done a
|
||
tremendous job in getting the physicians involved. The physicians are
|
||
given a say as to what information is important, what should be in the
|
||
reports, and how to use the data. Epstein continues, "The problem we're
|
||
having now is that we're OVERWHELMED with requests for more diagnosis
|
||
studies and more special reports from the physicians."
|
||
|
||
|
||
What Can Be Learned from CRTS/QURI
|
||
|
||
The QURI system includes the following components: infection
|
||
surveillance, drug use evaluation, blood usage review, surgical case
|
||
review, monitoring and evaluation, physician demographics, case
|
||
review/peer review, incident/occurrence monitoring, claims management
|
||
and utilization review. This information, as well as information from
|
||
patient's charts is used to provide reports, graphs and charts to
|
||
individual physicians or specialty groups.
|
||
|
||
Hospital-wide comparisons can be trended over time and be compared to
|
||
statewide averages or averages reported in the literature when
|
||
available. Comparisons between the 473 diagnoses can be evaluated and
|
||
compared to literature or statewide averages when available. Using the
|
||
severity groups, computer generated graphs and charts can be presented
|
||
to physician specialty groups and/or individual physicians displaying
|
||
how they compare to their average hospitalwide peer or to their average
|
||
within a specialty group for many resource and quality issues (see
|
||
Comparative Information sidebar). Cases with similar severity levels
|
||
can be found and treatments compared. Trends are also revealed in these
|
||
same graphs depicting how a physician compares throughout severity
|
||
levels. A physician or group may practice more efficiently and with
|
||
improved quality when treating higher severity level patients. More
|
||
indepth studies can be provided, such as how a physician's expired
|
||
patient with a certain severity level was treated, what procedures and
|
||
services were used, etc., versus other similarly ill patients.
|
||
During a report review a question may come up such as why did Risk
|
||
Management note that there was a problem? One possible scenario might
|
||
be that the patient fell out of bed and a closer look at the report
|
||
would show if Quality assurance reported that too much sedation was
|
||
given. One report from the CRTS brings it all together.
|
||
|
||
|
||
How It Began at Anderson Memorial
|
||
|
||
The first diagnosis chosen for the program was DRG89 - pleurisy/
|
||
pneumonia. Compared to the national norm, the hospital mortality rate
|
||
was higher. In addition, the hospital was losing money from cost
|
||
overruns since insurance companies and medicare coverage have limits on
|
||
what they will pay. It was learned that pneumonia of unknown etiology
|
||
had the highest mortality. The reports showed that patients of family
|
||
practitioners had longer lengths of stay.
|
||
|
||
A typical scenario unfolded. Physicians would start their patients on
|
||
antibiotics, wait for lab results (which were inconclusive more than 25%
|
||
of the time) then ask for an internal medicine consult on the third day.
|
||
Then treatment started all over. These patients stayed an average of 4
|
||
days longer and the hospital averaged a $2764 loss. Since this
|
||
discovery, Family Practitioners now get an earlier consult. Further
|
||
research found that the sputum collection procedure was a problem. The
|
||
hospital now uses respiratory therapy to collect specimens. Samples are
|
||
quickly tested and thrown out if they are spit instead of sputum from
|
||
the lungs. The inadequate sputum rate decreased from 26% to 5%. The
|
||
improvements caused a drop of $1091 in treating an average case of
|
||
pneumonia during the pilot program even though only half of the
|
||
physicians were involved in the program.
|
||
|
||
Other improvements for DRG89 followed. The length of stay and charges
|
||
continued to fall through 1989. Complications and mortality rates also
|
||
decreased. The use of ancillary services and ICU decreased. When
|
||
another diagnosis was added to the program, cerebovascular disease, the
|
||
hospital experienced a decrease in total charge of $1043 per patient,
|
||
even though CAT scans increased. Average length of stay also decreased.
|
||
Anderson Memorial is now using nine diagnoses in its program.
|
||
|
||
What's Downstream
|
||
|
||
In response to the national concern for the quality of health care, the
|
||
South Carolina Hospital Association voted to approve a statewide Quality
|
||
Indicators Project with the state. The tracking method was developed by
|
||
the Systems Development and Data Research department at Anderson
|
||
Memorial. Epstein is currently working with the state of South Carolina
|
||
to develop a software package which will look at quality issues for
|
||
statewide comparisons.
|
||
|
||
Seen as only the beginning, Epstein hopes to use the results of this
|
||
statewide quality project as a basis for designing another neural
|
||
network for use in the hospital. This neural network would screen all
|
||
patient charts and other data to provide a quality index (based upon the
|
||
statewide issues such as mortality, infections, etc.). He proposes that
|
||
the results could be used to decide which cases should be reviewed,
|
||
instead of randomly picking charts to look at. "There are too many
|
||
patients and too much data for someone to look at every single one and
|
||
decide which ones have quality issues that need looking into with a peer
|
||
review," Epstein says. This new neural network would make educating
|
||
physicians a much more efficient process as well as improve the quality
|
||
of care even further.
|
||
|
||
Currently, Anderson Memorial is working with three other hospitals as
|
||
they start their own program. A recent presentation of the CRTS/QURI
|
||
system at an American College of Physician Executives conference
|
||
produced an overwhelming response. The hospital has been beseiged with
|
||
requests for more information from other interested hospitals.
|
||
|
||
In the very near future at a meeting with seven hospitals from a
|
||
hospital network, Epstein will propose a hospital-group program. In
|
||
this program, there would be one neural network trained for each
|
||
hospital, plus one for all the hospitals using one diagnosis initially.
|
||
An overall advisory group would be formed. Comparisons could be made
|
||
between hospitals, between physicians and the seven-hospital average, as
|
||
well as all the currently implemented comparisons. If approved, he
|
||
plans to start the program in a few months. After a six-month pilot
|
||
program, results will be checked and verified. And this is only the
|
||
beginning.
|
||
|
||
*****************************************************************************
|
||
|
||
|
||
The CRTS program can provide comparative information for the following:
|
||
|
||
Resource Indicators Quality Indicators
|
||
------------------- ------------------
|
||
total patient charge inpatient mortality
|
||
length of stay unplanned readmissions
|
||
ancillary charge hospital-acquired infections
|
||
ancillary ratio surgical-wound infections
|
||
ICU days neonatal mortality
|
||
number of consultants perioperative mortality
|
||
cardiopulmonary charges Cesaerean sections
|
||
physical therapy charges unplanned returns to special
|
||
laboratory charges care unit
|
||
radiology charges unplanned returns to O.R.
|
||
catscan charges
|
||
pharmacy charges
|
||
IV solutions required
|
||
|
||
*****************************************************************************
|
||
|
||
Note: The bulk of this material is expected to be printed in PCAI
|
||
approximately November, 1990.
|
||
|