introduction
DRG standards and development in Australia
DRG Grouper software certified for use in Australia
DRG coding system
common DRG codes for EOU/SSU admissions in Victoria

Australian Refined Diagnosis Related Groups (AR-DRGs)

introduction

DRGs is a system of classifying patients in a manner primarily related to their principal diagnosis and co-morbidities, procedures and complications, which forms the basis for calculation of public hospital funding in Australia as well as many other countries.
it consists of about 670 patient classes and the allocated class can then be used to determine the Weighted Inlier Equivalent Separation (WIES) value (depending upon patient's actual LOS as against expected range and various other factors) for a given patient admission and this in turn can be given a dollar value.
a DRG Group program is generally used to determine which DRG is appriopriately assigned for a patient's admission based on coded ICD diagnosis, additional diagnoses and procedural codes (of which there are over 24,000 ICD codes)

DRG standards and development in Australia

the National Casemix and Classification Centre (NCCC), is part of the Australian Health Services Research Institute (AHSRI), University of Wollongong. The NCCC was formed in March 2010 following the successful bid to Australian Govt Department of Health and Ageing (DoHA) by the University of Wollongong (UoW) to develop:
- the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM), the Australian Classification of Health Interventions (ACHI), and the Australian Coding Standards (ACS) – these are collectively known as ‘ICD-10-AM/ACHI/ACS’, and
- the Australian Refined Diagnosis Related Group (AR-DRG) classification, Version 7.0.
in 2012-13, Victoria uses VicDRG6.0x table which has 10 additional DRG's compared to AR-DRG6.0 - these are created by splitting or modifying parent DRG's including J06Z, J07Z, O01A, O01B, O60Z, O64Z, O66Z, U61Z, U63Z and V60Z.

DRG Grouper software certified for use in Australia

DRG Grouper software requires certification by NCCC that it delivers accurate results and software developers must also hold licences issued by the Independent Hospital Pricing Authority (IHPA) allowing them to sell their product within AR-DRG licenced countries.
see NCCC Grouper Certification and software vendors

DRG coding system

DRGs are based upon 23 major diagnostic categories (MDC)
- see MDC and DRG descriptions hosted on NCCC
- one can purchase manuals or electronic lists from NCCC online ordering
- NCCC's CodeXpert coding software - but is NOT a DRG Grouper!
for a given admission, a DRG Grouper analyses the patient age, sex, and clinical edits (principal diagnosis, additional diagnoses, procedures) then sequentially:
- assigns a MDC
- performs pre-MDC processing
- adjacent DRG (ADRG) assignment
- Complication and comorbidity level (CCL) and patient clinical complexity level (PCCL) assignment
- final DRG assignment

1st character of code

the 1st character of a DRG code refers to the major diagnostic category (except for A = pre MDC, 8=unrelated OR procedure, 9 = error)
B = neurology and cranial
C = ophthalmology
D = head and neck and ENT
E = respiratory and thoracic
F = cardiovascular and cardiac
G = gastroenterology and abdominal
H = hepatobiliary
I = orthopaedic incl. spinal surgery, soft tissue and hand injuries
J = skin, plastics, breast
K = endocrine
L = renal and urologic
M = male genital incl. prostatic
N = female genital / gynaecology
O = obstetric
P = neonatal
Q = haematologogic incl. spleen
R = lymphoma, leukaemia, chemotherapy, radiotherapy
S = HIV related
T = septicaemia, post-op infections, PUO, viral infections
U = mental health
V = drug and alcohol
W = multi-trauma
X = other trauma, allergic reactions, poisoning, complications
Y = burns
Z = rehabilitation, diagnoses of other contacts, signs and symptoms only, post-op review
8 = procedures unrelated to principal diagnosis
960Z = ungroupable

next 2 characters

identify the adjacent DRG and it’s partition, usually most to least complex:
- x01x – x39x are surgical DRGs
- x40x – x59x are other non-surgical procedural DRGs (eg. endoscopy)
- x60x – x99x are medical DRGs

last character

represents the resource consumption split within an adjacent DRG
split is based on PCCL, malignancy, same day status, MHLS, mode of separation, length of stay, and specific diagnoses or procedures
eg. xnnA, xnnB, xnnC, xnnD, xnnZ
- A highest consumption of resources (eg. with catastrophic CC)
- B second highest consumption of resources (eg. with severe CC)
- C third highest consumption of resources (eg. without catastrophic or severe CC)
- D fourth highest consumption of resources (eg. died or transferred < 5 days)
- Z no split for the ADRG
CC = specific complication and/or co-morbidity codes
- these are likely to increase resource utilisation and thus costs
- the Grouper assigns a severity weight (CC Level or CCL) to each additional diagnosis or procedure it encounters:
  - CCL=0 not a CC
  - CCL=1 minor CC
  - CCL=2 moderate CC
  - CCL=3 severe CC
  - CCL=4 catastrophic
- a diagnosis may have a different CCL depending on whether ADRG is medical or surgical, and on the ADRG itself
- hypokalaemia or hyperkalaemia may be 3 or 4 if surgical, or 2 or 3 if medical
- fluid overload may be 2 or 3
- early dementia may be 2,3 (or even 4 for some surgical ADRGs)
- resp. failure defined as documented hypoxia is an important CC
Patient Clinical Complexity Level (PCCL):
- an algorithm is used to calculate the patient clinical complexity level (PCCL) from multiple CCL values
- PCCL is a measure of the cumulative effect of CCs and is calculated for each episode
- calculation is complex and has been designed to prevent similar conditions from being counted more than once
- CC codes are ranked alphabetically in descending order of CCL value and the Recursive Exclusion Process applied
- each diagnosis is treated as the principal diagnosis (‘anchor’) and the cc status of each remaining diagnosis is reviewed in relation to the ‘anchor’
- A PCCL value of:
  - 0 = no CC effect
  - 1 = minor CC
    - = CCL1
  - 2 = moderate CC
    - = CCL2
    - = CCL1 x 2
  - 3 = severe CC
    - = CCL4 or CCL3 +/- 1 CCL1
    - = CCL3 + CCL2 +/- CCL1
    - = CCL2 x 2 or 3
    - = CCL2 + CCL1
    - = 5 or more CCL1
  - 4 = catastrophic CC
    - = CCL4 + 1 or more other CCL
    - = CCL3 + CCL3
    - = CCL3 + 2x CCL2
    - = CCL3 + CCL2 + 2 or more CCL1
    - = CCL2 x 3 + another CCL2 or at least 3 CCL1

common DRG codes for EOU/SSU admissions in Victoria

WIES is generally reduced to 20-50% of a one day WIES if patient is discharged prior to midnight and thus only a same day stay instead of a one day (“overnight”) stay!

Without catastrophic or severe co-morbidities or complications

DRG code	Description	One day 2011-12 WIES (approx)
B63Z	dementia	0.90
B69B	TIA	0.46
B73Z	viral meningitis	0.75
B76B	seizure	0.56
B77Z	headache	0.41
B78B	intracranial injury	0.72
B79B	skull fracture	0.52
B80Z	other head injury	0.44
B81B	other neuro	0.46
D12Z	other ENT procedure ? tonsil aspiration	1.13
D62Z	epistaxis	0.31
D66B	other ENT diagnoses ?tonsillitis	0.43
E61B	pulm. embolism	1.26
E62B	resp. infections mod. CC	1.18 multi-day
E62C	resp. infections no CC	0.66
E64B	pulm. oedema with resp. failure	0.73
E65B	COPD	0.28
E67B	resp. signs/symptoms	0.30
E68B	pneumothorax	0.62
E69B	asthma / bronchitis	0.46?
E69A	asthma with CC	0.83
E73B	pleural effusion mod. CC	0.28
E74B	interstitial lung disease, mod. CC	1.23
E74C	interstitial lung disease, no CC	0.62
E75B	other resp. mod. CC	0.95
E75C	other resp. w/o CC	0.47
F63B	DVT	0.79
F66B	coronary atherosclerosis	0.36
F67B	hypertension	0.35
F72B	unstable angina	0.60
F73B	syncope or collapse	0.14
F74Z	chest pain	0.36
F76B	arrythmia	0.58
G66Z	abdo pain	0.44
G67B	GOR or gastro	0.41
H64B	biliary colic	0.57
I74Z	injured wrist/hand/foot	0.51
I75A	injured shoulder/elbow/knee/ankle w CC	0.78
I75B	injured shoulder/elbow/knee/ankle w/o CC	0.49
I76B	other m/skel w/o severe CC	0.58
K60B	diabetes w/o severe CC	0.85
L60C	renal failure	0.25
L63B	UTI / pyelonephritis	0.57
L64Z	renal colic	0.46
L65B	other renal S/S	0.47
L67B	other renal Dx ?retention	0.60
M61Z	benign prostatic hypertrophy	0.36
N61Z	endometritis/ PID	0.21
N62Z	menorrhagia	0.26
O03B	ectopic pregnancy	1.02
O63Z	miscarriage	0.39
O61Z	RPOC w/o theatre	0.55
T60B	septicaemia	0.36
T61B	post-op infections	0.21
T62B	fever unknown origin	0.25
T63Z	viral infection	0.52
T64B	other infections with mod CC	1.06
T64C	other infections w/o CC	0.87
U60Z	mental health	0.18
U61B	schizophrenia	0.32
U65Z	anxiety	0.27
V60B	alcohol intoxication	0.30
V71Z	drug intoxication	0.27
V62A	alcohol use disorder and dependence	0.78
V63Z	opioid use disorder and dependence	0.74
V64Z	other drug use disorder and dependence	0.41
X60B	injuries	0.40
X61Z	allergic reactions	0.23
X62B	poisoning	0.39
Y61Z	severe burns	0.37
Y62B	other burns	0.29
Z61A	symptoms /signs	0.34
Z61B	symptoms / signs same day	0.22
Z63B	follow up post-op care	0.24

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