Table 2

Comparison between the WHO ICD-9 and ICD-10 classifications

Name of classificationInternational Classification of DiseasesInternational Statistical Classification of Diseases and Related Health Problems
No of volumes(1) Volume 1—tabular list(1) Volume 1—tabular index
(2) Volume 2—alphabetical index(2) Volume 2—instruction manual
(3) Volume 3—alphabetical index
No of sections vs chapters17 sections (001–099)21 chapters (A00-Z99)
Except for U codes
U00–U49: reserved for the provisional assignment of new diseases of unknown causes
U50–U99: for research purposes
Supplementary classificationsTwo supplementary classificationsNo supplementary classifications (prior supplementary classifications are now their own chapters)
(1) External causes of injury and poisoning (E800–E999)
(2) Factors influencing health status and contact with health services (V01–V82)(1) Chapter XX: external causes of morbidity and mortality (V01–Y98)
(2) Chapter XXI: factors influencing health status and contact with health services
Subcategories516112 159
Total codes688212 420
  • Source: Jetté N, et al.22