Health informatics and the
importance of coding
Anthony Madden
Abstract
Health informatics can be defined as ‘The knowledge, skills and tools
which enable information to be collected, managed, used and shared,
to support the delivery of healthcare and to promote health.’ The use
of computers in informatics requires standardized codes to identify synonymous medical terms. The International Statistical Classification of
Diseases and Related Health Problems, 10th revision, (ICD-10) is used
internationally to code morbidity and mortality; the Office of Population
Censuses and Surveys Classification of Surgical Operations and Procedures, 4th revision, (OPCS-4) is used in the UK to code operations and
procedures; Read codes and Clinical Terms Version 3 (CTV3) are used in
primary care systems. Systemized Nomenclature of Medicine Clinical Terminology (SNOMED CT) incorporates all these coding systems. ICD-10 and
OPCS-4 are fundamental to Payment by Results, the method by which
healthcare providers in the NHS in England are paid.
Keywords ICD-10; informatics; OPCS-4; Payment by Results; Read
codes; SNOMED
Royal College of Anaesthetists CPD Matrix: 3J00
What is health informatics?
Health informatics, sometimes called healthcare informatics,
biomedical informatics, or medical informatics, can be defined as
‘The knowledge, skills and tools which enable information to be
collected, managed, used and shared, to support the delivery of
healthcare and to promote health’. Computers are just one of the
tools used.
Some knowledge of health informatics is required by the
Royal College of Anaesthetists.
Standard terminology e why?
Medical records are the underlying source of data for compiling
healthcare statistics and paying hospitals for their activities. They
are increasingly computerized. One problem is that computers
are essentially stupid. Human beings can understand that the
terms ‘suxamethonium apnoea’, ‘sux apnoea’, and ‘scoline
apnoea’ all describe the same concept, but to a computer they are
different. To overcome this problem in computerized medical
records either the same term must always be used, or there must
be a code attached to different terms that mean the same thing.
The former approach is impractical so current approaches are
focused on providing a thesaurus of terms with codes attached to
indicate terms with identical meaning.
Towards a standard terminology
ICD-10, the International Statistical Classification of Diseases and
Related Health Problems, 10th revision, is used for coding the
causes of death recorded on death certificates, for coding hospital
episodes, and for monitoring morbidity and mortality. The origins of ICD-10 can be traced back to the late 16th century when
London parishes began to publish death statistics but the terms
used were not standardized. When William Farr was appointed
as the first medical statistician of the General Register Office of
England and Wales in 1837 he tried to solve the problem by
producing the first internationally applicable classification of
causes of death. This formed the basis of Bertillon’s Classification
of Causes of Death, adopted at an international meeting in 1893.
The fifth revision (ICD-5) was published in 1938.
Work had continued separately on classifying the causes of
diseases which were included in the Sixth Revision in 1948. The
World Health Organization has been responsible for maintaining
the ICD since then. ICD-10 was published in 1990 and has been
updated regularly. ICD-11 is now being prepared with a view to
publication in 2015.
OPCS-4, the Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, 4th revision, is a
uniquely British product used for coding and monitoring surgical
activity. Its origins go back to 1944 and the 4th revision was
published in 1987. An attempt to replace it with a new National
Intervention Classification was abandoned in 2005. OPCS-4 is
revised regularly; OPCS-4.6 was mandated for use in 2011e12.
ICD-10 and OPCS-4 use the same coding schema with codes
from A00.0 to Z99.9 so there is potential for confusion with the
same code applying to radically different things in the two systems (Table 1). There is also some overlap, especially in the area
of obstetric care.

After reading this article you should understand the:
C nature of health informatics
C main coding systems: ICD-10, OPCS-4, Read, and SNOMED
C importance of coding

ICD-10 OPCS-4
International
Diagnoses
Codes from A00.0 to Z99.9
Code H47.1 ¼ papilloedema
unspecified
UK only
Procedures
Codes from A00.0 to Z99.9
Code H47.1 ¼ excision of
sphincter of anus
Table 1
Anthony Madden FRCA is a retired Consultant Anaesthetist who worked
at Southmead Hospital, Bristol, UK. Conflicts of interest: none declared.
INFORMATICS
ANAESTHESIA AND INTENSIVE CARE MEDICINE 15:2 62
2014 Elsevier Ltd. All rights reserved.
Read Codes were the invention of the late Dr James Read, a GP
in Loughborough. The 4-byte version in 1984 had 10,000 codes,
while the 5-byte version in 1988 had 30,000. The coding system
was hierarchical so the codes had implied meaning, for example
all respiratory diseases were classified under ‘H’.
The NHS bought the copyright from Dr Read and produced
Read Clinical Terms Version 3 in 1994. CTV3 incorporates all
ICD-10 and OPCS-4 codes and provides a consistent means of
recording information in primary care record systems. It is still
updated regularly.
SNOMED, the Systemized Nomenclature of Medicine, started in
1965 as the Systemized Nomenclature of Pathology, produced by
the College of American Pathologists (CAP). Medical terms were
incorporated in 1974 to create SNOMED. In the late 1990s the
NHS and the CAP agreed to combine SNOMED and CTV3 as
SNOMED Clinical Terminology (CT), first released in 2002. The
International Health Terminology Standards Development Organisation (IHTSDO) in Copenhagen assumed responsibility for
maintaining SNOMED in 2007 and updates it every 6 months.
There are versions in American English, British English, Danish,
Spanish and Swedish. Translation into other languages is in
progress.
SNOMED contains 311,000 active concepts, 758,000 active
descriptions and 823,000 defining relationships. All the terms in
ICD-10 and OPCS-4 are included. A purely numerical code is used
to identify each unique concept. NHS policy is to use only
SNOMED codes in the future.
The importance of coding
Payment by Results (PbR) is the system for paying NHS care providers in England. At first it only applied to elective hospital care
but it now covers most activity. The diagnoses and treatments used
on an individual patient are coded using ICD-10 and OPCS-4. These
codes are entered into a computer program that turns them into a
Healthcare Resource Group (HRG). Every HRG code has a standard
NHS price, and the appropriate payment is then made to the hospital (Table 2). Coding therefore determines a hospital’s income.A
FURTHER READING
www.connectingforhealth.nhs.uk
www.dh.gov.uk
www.ihtsdo.org
www.who.int/classifications/icd/en/

Incomplete coding: Correct coding:
T21.3 (ICD-10) Burn of third degree of trunk
T22.1 (ICD-10) Burn of first degree of shoulder and upper limb
except wrist and hand
S36.2 (OPCS-4) Full thickness autograft of skin nec
HRG J26 Costs [ £2489
T21.3 (ICD-10) Burn of third degree of trunk
T22.1 (ICD-10) Burn of first degree of shoulder and upper limb
except wrist and hand
T31.2 (ICD-10) Burns involving 20e29% body surface
S35.2 (OPCS-4) Meshed split autograft of skin nec
Z49.3 (OPCS-4) Skin of anterior trunk
HRG J20 Costs [ £6987
Note: The costs are illustrative only.
Table 2
INFORMATICS
ANAESTHESIA AND INTENSIVE CARE MEDICINE 15:2 63
2014 Elsevier Ltd. All rights reserved.