The document discusses disease classification and the International Classification of Diseases (ICD). It provides definitions of disease and classification, and outlines the history and types of disease classification. It describes the ICD-10 system which has 21 chapters arranged across 3 volumes and over 14,400 codes. The purpose of ICD is to facilitate the standardized collection and reporting of health data globally. Some challenges to ICD coding include its size, lack of training, and software issues.

1. Disease Classification
Dr. Shaikh Balan Mahetab
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2. Learning Objectives
Definitions
Background
Classification Types
ICD – 10
Problems faced
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3. Definitions
Disease –
Deviation from the state of complete
physical, mental and social well-being
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4. Classification
The process of putting things into groups based on ways that they are alike.
Classification of diseases: Arrangement of diseases into groups having
common characteristics.
Medical classification is the process of transforming descriptions of
medical diagnoses and procedures into universal medical code numbers.
E.g. : ICD, ICF, ICHI, NDC
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6. Background
 Earliest evidence of classifications appear as some groupings of diseases in the early writings of the
Greeks and Romans.
 John Graunt (1620 – 1674) arranged the diseases in alphabetical order in his work Bills of
Mortality.
 Francois Bossier de Lacroix (1706-1777) conceived the idea of classification of diseases and
published it under the title Nosologia methodica.
 William Farr (1807-1883)- the First medical statistician who spelt out principles that should govern
a statistical classification of disease and urged the adoption of a uniform classification
internationally.
The first version of ICD was adopted in 1893 chicogo , in 1898 recommended the revisions of
the classification every ten years.
First starting in 1900 – The First Revision (ICD–1) Presently ICD 10 since 1993
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7. • On various approach diseases are classified as ..
1. Topographical or Systemic , by bodily region or system,
gastrointestinal disease, vascular disease, abdominal disease,
and chest disease etc
2. Anatomical, by organ or tissue,
cardiac disease, hepatic disease, and pulmonary disease etc
3. Physiological, by function affect,
respiratory and metabolic syndrome, DM , gout, hyperacidity
4. Pathological, by the nature of the disease process,
Neoplastic and inflammatory disease
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Types

8. 5. Etiological (causal),
• communicable ..bacterial, viral, parasitic ,vector born ,water
born zoonotic , STDs etc
• non communicable .. Hereditary , Life style related , accidental,
injuries , nutritional
6. Juristic, Medicolegal,
7. Epidemiological, Sporadic , outbreak , epidemic pandemic
endemic etc
• Any single disease may fall within several of these classifications.
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Types

9. • Work on ICD-10 began in 1983 and was completed in 1992 and is
in use from 1994 to present day.
• The ICD - 10 allows more than 14,400 different codes and permits
the tracking of many new diagnoses. The codes can be expanded
to over 16,000 codes by using optional sub-classifications.
• ICD – 10 is arranged in 21 major chapters.
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International Classification of Diseases (ICD – 10)

10. 10
Chapter Blocks Title
I A00–B99
Certain infectious and parasitic
diseases
II C00–D48 Neoplasms
III D50–D89
Diseases of the blood and blood-
forming organs and certain
disorders involving the immune
mechanism
IV E00–E90
Endocrine, nutritional and
metabolic diseases
V F00–F99
Mental and behavioural
disorders
VI G00–G99 Diseases of the nervous system
VII H00–H59 Diseases of the eye and adnexa
VIII H60–H95
Diseases of the ear and mastoid
process
IX I00–I99
Diseases of the circulatory
system

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Chapter Blocks Title
X J00–J99
Diseases of the respiratory
system
XI K00–K93 Diseases of the digestive system
XII L00–L99
Diseases of the skin and
subcutaneous tissue
XIII M00–M99
Diseases of the musculoskeletal
system and connective tissue
XIV N00–N99
Diseases of the genitourinary
system
XV O00–O99
Pregnancy, childbirth and the
puerperium
XVI P00–P96
Certain conditions originating in
the perinatal period
XVII Q00–Q99
Congenital malformations,
deformations and chromosomal
abnormalities

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Chapter Blocks Title
XVIII R00–R99
Symptoms, signs and abnormal
clinical and laboratory findings,
not elsewhere classified
XIX S00–T98
Injury, poisoning and certain
other consequences of external
causes
XX V01–Y98
External causes of morbidity
and mortality
XXI Z00–Z99
Factors influencing health
status and contact with health
services
XXII U00–U99 Codes for special purposes

13. Coding System
A N N . N
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1. First character is associated with the particular chapter.
2. D is used in chapters II and III and letter H is used in chapter VII
and VIII.
3. Chapters I, II, XIX and XX use more than one letters in their first
position of the codes.
4. Each chapter have three character categories to cover its contents. A
fourth numeric character is added after decimal for sub categories.
5. Unused U codes are to be used for provisional assignment of new
diseases of uncertain aetiology.

14. Arrangement of Volumes of ICD-10
• Volume 1: Main classifications
• Volume 2: Instruction/ Guidance to users
• Volume 3: Alphabetical Index
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15. Purpose and use of ICD
• To identify health trends and statistics globally
• It is the international standard for defining and reporting
diseases
• Comprehensive compilation
• Global uniformity
• It is the diagnostic classification standard for all clinical and
research purposes
• easy storage, retrieval, analysis and comparison of the data
collected in different countries or areas and at different times.
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16. Problems encountered
• Size of the Classification
• No formal training
• No user-friendly software to guide
• No Online Help-line system
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17. Summary
 Definitions disease and classification
Classification of diseases is the Arrangement of diseases into
groups having common characteristics.
 History
 Type Of classification .. Based on different approaches
 ICD 10
ICD maintained and revised under WHO every 10 years.
The purpose of the ICD is to permit the systematic recording,
analysis, interpretation and comparison of mortality and
morbidity data collected.
ICD – 10 has 21 chapters, 3 volumes.
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18. Questions
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19. Which of the following is true about ICD 10
1. Unique alphabet is used for each chapter
2. Consists of 10 chapters
3. Arranged in 3 volumes
4. Was produced by UNICEF
Answer: 3 i.e. Arranged in 3 volumes
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20. ICD 10 has how many chapters
1. 5
2. 12
3. 21
4. 23
Answer : 3 i.e. 21
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21. Further Reading
• History of the Statistical Classification of Diseases and Causes of
Death at
http://www.cdc.gov/nchs/data/misc/classification_diseases2011.
pdf
• International Classification of Diseases, Tenth Revision, Clinical
Modification (ICD-10-CM) at
http://www.cdc.gov/nchs/icd/icd10cm.htm
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22. References
1. Park’s Textbook of Preventive and Social Medicine, 23rd Edition.
2. WHO (1993) International Statistical Classification of Diseases
and Related Health Problems, Tenth Revision, Vol. 2 .
3. A Dictionary of Epidemiology by J. Last, 5th Edition
4. Accessed http://www.who.int/classifications/icd/en/
5. Accessed http://www.cdc.gov/nchs/icd/icd10.htm
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