Surprising though it may seem, until now the World Health Organisation’s International Classification of Diseases (ICD) has not included a diagnostic code for any form of chronic pain. That has made the classification of conditions such as CRPS and Fibromyalgia under ICD very difficult. Now, with the next revision of ICD – ICD 11 – that is set to change.
If adopted by Member States, ICD 11 will come into force on 1st January 2022 and the inclusion of chronic pain and a number of sub-categories at last provides international recognition of just how widespread a problem it is. In fact, it is thought that one in five people worldwide suffer with some form of chronic pain.
The new ICD classification for chronic pain has been formulated by a Task Force set up by the International Association for the Study of Pain (IASP) and is based upon extensive research and data collected over the last six years, as well the biopsychosocial model, which has been considered in an earlier article.
Categories of pain
In addition to “Chronic Primary Pain” where chronic pain represents the condition itself, there are six sub-categories of chronic secondary pain which arise from an underlying condition categorised elsewhere:
- Chronic cancer-related pain;
- Chronic post-surgical or post-traumatic pain;
- Chronic neuropathic pain;
- Chronic secondary headache or orofacial pain;
- Chronic secondary visceral pain;
- Chronic secondary musculoskeletal pain.
Under the new classification, both CRPS and Fibromyalgia fall under the banner of Chronic Primary Pain.
IASP’s President, Dr Lars Arendt-Nielsen, said “The inclusion of the new classification system for chronic pain in ICD-11 is an important milestone for the pain field. IASP leadership, on behalf of our members, thanks the member states of the WHO for their leadership in improving patient evaluation, treatment, and research.”