Medicine's master code list includes a code for being struck by a cow
ICD-10, the World Health Organization's catalogue of diseases, symptoms and injuries, took effect in 1993 with more than 14,000 codes. America's version ballooned to over 69,000 diagnosis codes, including one for being struck by a cow and another for burns from water-skis on fire, and the switch to it slipped past two deadlines.
Work on the tenth revision started in 1983. The Forty-third World Health Assembly endorsed it in 1990, member states began using it on January 1, 1993, and ICD-11 superseded it on January 1, 2022. Beyond diseases it codes signs and symptoms, abnormal test results, complaints, social circumstances and the external causes of injuries, and optional extra digits can record cause, site, severity and type. The untouched international edition underpins cause-of-death statistics in 117 countries, while roughly 27 use it to decide payments and allocate health resources.
Many governments tailored their own editions. Australia's ICD-10-AM, introduced in 1998 by a classification centre at the University of Sydney, was taken up by New Zealand, Ireland and Saudi Arabia, among others. Germany built its GM version on the Australian one between 2003 and 2004, and since 2020 the Federal Institute for Drugs and Medical Devices has looked after it; Switzerland uses the same edition and reissues it in French and Italian every two years, and Greece switched on December 23, 2023. Canada began using ICD-10 for death records in 2000 and phased in its own variant over six years from 2001, with Quebec last. Thailand's edition has an index that runs in both Thai and English.
The American variant was the most dramatic. Developed by the Centers for Medicare and Medicaid Services with the National Center for Health Statistics, ICD-10-CM carries over 69,000 diagnosis codes and its companion procedure system over 70,000, against about 14,000 and 3,800 in the older ICD-9-CM. Providers objected to the sheer volume, complexity and expense, but CMS concluded that staying on ICD-9-CM was costlier for finances and public health. A deadline of October 1, 2013 slid to 2014 and finally to October 1, 2015.
Two complaints stuck. Coders face long menus of near-identical options for common conditions such as rheumatoid arthritis, slowing their work, and critics mock hyper-specific entries like W55.22XA, a first visit after being struck by a cow. Supporters answer that the alphanumeric format fixed the cramped, rigid structure of ICD-9 and captures diagnoses far more precisely.
Source: ICD-10
