Diagnosis Related Groups
(DRGs)

Diagnosis Related Group (DRG):
is a payment category that is used to classify patients,
especially
Medicare
patients,
for
the
purpose
of
reimbursing hospitals for each case in a given category
with a fixed fee regardless of the actual costs incurred.

DRG is based upon:

the principal ICD-9-CM diagnosis code

ICD-9-CM surgical procedure code

age of patient

expected length of stay in the hospital
History

In the mid 1970s the Centre for Health
Studies at Yale University began work on a
system for monitoring hospital utilization
review. Following a 1976 trial of a DRG
system, it was decided to base the final
system on the ICD-9-CM which would provide
the basic diagnostic categories
Purpose.

relate a patient’s diagnosis and treatment to the cost of
their care

Developed in the United States by the Health Care Finance
Administration

DRGs are used for reimbursement in the prospective
payment system of US Medicare and Medicaid healthcare
insurance systems

DRGs were designed to support the calculation of federal
reimbursement for healthcare delivered through the U.S.
Medicare system
DRG Structure

Major Diagnostic category

Medical Surgical split

Complications & Comorbidities

Exclusion list

Structure diagram

DRG Example with severity score
Major Diagnostic Category Assignment
(MDC)

The initial step in the determination of the
DRG has always been the assignment to
the appropriate MDC based on the
Principal Diagnosis

Since the presence of a surgical
procedure requires different hospital
resources (operating room, recovery
room, anesthesia) most MDCs were
initially divided into medical and surgical
groups
Medical Surgical split
All procedure codes were classified based
on whether or not they required the use of
an operating room





Operating room procedures
– Cholecystectomies
– Cerebral meninges biopsies
– Closed heart valvotomies
Non operating room procedures
– Bronchoscopy
– Skin sutures
Complications & Comorbidities
(CCs)



A complication is a condition which did not
exist prior to the admission
A comorbidity is a condition which existed
prior to admission
A complication or comorbidity is a secondary
diagnosis which would be expected to extend
the patient’s length of stay by at least one day
in at least 75 percent of patients
Major CCs

Within each MDC patients with major CCs
(e.g., AMI, CVA, etc.) were assigned to
separate DRGs

A major complication or comorbidity is a
secondary diagnosis which would be
expected to extend the patient’s length of
stay by at least 3-4 days in at least 75
percent of patients
Complication & Comorbidity
(CC) Exclusion List
For a principal diagnosis of bladder neck
obstruction
– Urinary retention is not a CC

For a principal diagnosis of general
convulsive epilepsy
– Convulsion is not a CC

Surgical Hierarchy

If multiple procedures are present, the
patient is assigned to a single surgical
DRG based on a surgical hierarchy within
each MDC
DRG assignment

A DRG is assigned based on the patient's diagnosis
(ICD-9-CM coding). The encoder (also known as the
DRG grouper) is a software program developed by
CMS that places the patient into a Major Diagnostic
Category based on the diagnosis.

For example: A patient with a fracture would be
grouped to the Musculoskeletal Major Diagnostic
Category. At this point, the patient is considered a
medical DRG. If the patient has a surgical procedure,
then the patient is grouped to a surgical DRG. The
other factors that influence DRG assignment is age of
the patient, any complication/comorbidities, and
discharge status.
Limitations
DRGs will always only give approximate estimates of the true
resource utilisation. For example, should a hospital that is
developing new and expensive procedures be paid the same amount
as an institution that treats the same type of patient with a more
common and cheaper procedure? Should quality of care be reflected
in a DRG? For example, if a hospital delivers good quality of care
that results in better patient outcomes, should it be paid the same as
a hospital that performs more poorly for the same type of patient?
As importantly, those institutions that are best able to create DRGs
accurately are more likely to receive reimbursement in line with
their true expenditure on care. There is thus an implication in the
DRG model that an institution actually has the ability to accurately
assemble information to derive DRGs . Given local and national
variations in information systems and coding practice, it is likely
that institutions with poor information systems will be
disadvantaged.
Developments

DRGs are designed for use with inpatients.
Accordingly, other systems have been developed
for other areas of healthcare. Systems such as
Ambulatory Visit Groups (AVGs) and Ambulatory
Payment
Classifications
(APCs)
have
been
developed for outpatient or ambulatory care in the
primary sector. These are based upon a patient’s
diagnosis, intervention, visit status and physician
time.
DRG audits
DRG audits may consists of evaluating those
DRGs that are incorrectly used. These
audits may also focus on missing
diagnoses, missing procedures, and
incorrect principal diagnosis selection
For DRG based reviews, cases may be selected in a variety of
ways:
 • Simple random sample
 • High dollar and high volume DRGs
 • DRGs without comorbid conditions or complications
 • Focused DRGs such as DRG 79 Pneumonia or DRG 416
Septicemia and other high
 risk DRGs
 • Correct designation of patient discharge and transfer
status
‫ايران‬
‫در ايران اين نوع روش پرداخت بکار گرفته مي شود و نظام طبقه بندي اي که به‬
‫عنوان پايه و اساس جهت بکارگيري روش پرداخت موردي استفاده مي شود نظامي با‬
‫عنوان نظام" گلوبال" است‪ .‬در اين نظام‪ ،‬بيماران بر طبق ‪ 60‬مورد از اعمال جراحي‬
‫شايع طبقه بندي مي گردند‪ .‬نظام" گلوبال" در مقايسه با نظام "گروه هاي مرتبط‬
‫تشخيصي" داراي نواقص بسياري است‪ .‬نظام" گلوبال"‪ ،‬موارد بيماري را شامل نشده‬
‫و تنها در مورد اعمال جراحي و تنها در ‪ 60‬مورد کاربرد دارد‪ .‬طبقات تشخيصي‬
‫اصلي‪ ،‬گروه های مرتبط تشخيصی پايه که در نظام هاي "گروه هاي مرتبط‬
‫تشخيصي" بطور جامع و کامل در نظر گرفته شده است در نظام " گلوبال" وجود‬
‫ندارد‪ .‬همچنين طبقاتي جهت اطالعات غيرمعتبر و متناقض‪ ،‬و وضعيت ترخيص‬
‫بيمار در نظر گرفته نشده است‪ .‬متغيرهاي سن‪ ،‬جنس‪ ،‬وجود يا عدم وجود عوارض و‬
‫بيماري هاي همراه‪ ،‬سطح خاص عوارض و بيماري هاي همراه‪ ،‬وزن زمان تولد‪/‬‬
‫ايران‬
‫پذيرش در نوزادان وجود نداشته و شدت بيماري و يا سطح پيچيدگي‬
‫کلينيکي بيمار‪ ،‬و نيز خطرمرگ را نمي توان با توجه به اين نظام تعيين‬
‫نمود ‪ .‬در نظام هاي "گروه هاي مرتبط تشخيصي" به هر"گروه"‪ ،‬کدي‬
‫تعلق مي گيرد که با کدهاي طبقه بندي بين المللي بيماري ها مرتبط و‬
‫هماهنگ است‪ ،‬اما در نظام " گلوبال" کدگذاري انجام نمي شود‪ .‬از‬
‫طرفي ديگر عامل وزن نسبي يا وزن هزينه اي‪ ،‬که در محاسبه هزينه‬
‫بيمار با توجه به نظام "گروه های مرتبط تشخيصي" جهت هر گروه‪ ،‬به‬
‫طور جداگانه تعيين مي شود در نظام " گلوبال" درنظر گرفته نشده‬
‫است‪ .‬بدين ترتيب مي توان اظهار داشت نظام " گلوبال" در مقايسه با‬
‫نظام "گروه های مرتبط تشخيصي" داراي کمبود ها و نواقصي است ‪.‬‬