ABSTRACT
Box 6.1: International Classification of Diseases, tenth revision (ICD10) The International Classification of Disease has its origins at the end of the eighteenth century when the International Classification of Causes of Death was sponsored by the International Statistical Institute. In 1929 the fourth revision was produced in collaboration with the Health Organization of the League of Nations, and by the sixth revision (1948) the World Health Organization had assumed responsibility. This revision also included for the first time 'causes of morbidity', moving away from the concept of pure mortality statistics. The ninth revision (ICD-9) was used until April 1995 and, with its limitations (see below), was the basis for the early work on HRG development. The lack of specificity seen in the example below hampered the development of more specific grouping, but this will hopefully be rectified at least in part by ICD-10, which is amply demonstrated by the codes for subarachnoid haemorrhage:
ICD 9 Subarachnoid haemorrhage 430 Meningeal haemorrhage Ruptured (congenital) cerebral aneurysm:
NOS (not otherwise specified) syphilitic
ICD 10 Subarachnoid haemorrhage 160 160.0 Subarachnoid haemorrhage from carotid syphon and bifurcation 160.1 Subarachnoid haemorrhage from middle cerebral artery 160.2 Subarachnoid haemorrhage from anterior communicating artery 160.3 Subarachnoid haemorrhage from posterior communicating artery 160.4 Subarachnoid haemorrhage from basilar artery 160.5 Subarachnoid haemorrhage from vertebral artery 160.6 Subarachnoid haemorrhage from other intracranial arteries 160.7 Subarachnoid haemorrhage from intracranial artery unspecified 160.8 Other subarachnoid haemorrhage 160.9 Subarachnoid haemorrhage unspecified
The codes in ICD-10 are arranged alphanumerically in 21 chapters. The first character (a letter) gives the chapter, and the next two numbers give the broad category of disease. The qualifiers 0-9 (fourth character) give greater specificity. For example:
Box 6.1: continued
VIII Diseases of the ear and mastoid process (H60-H95) H60-H62 Diseases of external ear H63-H75 Diseases of middle ear and mastoid H80-H83 Diseases of inner ear H90-H95 Other disorders of ear
Diseases of the inner ear contains:
H80 Otosclerosis H81 Disorders of vestibular function H82 Vertiginous syndromes in diseases classified elsewhere H83 Other diseases of inner ear
Disorders of vestibular function is further broken down into:
H81.0 Menieres disease H81.1 Benign paroxysmal vertigo H81.2 Vestibular neuronitis etc.
