Chronic Pain Gets Its Own Condition Under ICD-11

As of January 1, 2022, the latest revision of the International Classification of Diseases (ICD), the ICD-11, became effective. Within the revisions are important changes and additions that affect people who live with chronic pain and the pain management specialists who diagnose and treat them. Pain specialists predict that the more accurate classification system and view of chronic pain will make life easier for those affected – as well as the physicians and advanced practitioners who care for them.

ICD-11 Chronic Pain Codes

A key “first” in ICD-11 is that the new system provides a single diagnostic code for chronic pain (MG30.0 Chronic primary pain). The manual also provides other codes for the most common and relevant groups of pain conditions. Under the ICD-11, pain is not only recognized as a health condition on its own but it is also recognized as a symptom that can be secondary to other underlying health issues. The revision makes clear that chronic pain can lead to disability and distress, which is likely to be a welcome direction for those who have experienced stigma toward their often invisible condition.

Chronic Pain Reclassified in ICD-11

Under the new classification, chronic pain is defined as ‘’pain that persists or recurs for more than 3 months,’’ as it has been previously. The classification goes even further to differentiate types of pain. Pain can be the sole or a leading complaint, needing special treatment and care. Other subgroups specify that pain may be secondary to an underlying disease. For instance, there can be chronic cancer-related pain, chronic neuropathic pain, chronic secondary visceral pain, and chronic secondary headache and orofacial pain, to name a few categories.

The ICD is maintained by the World Health Organization (WHO) and considered “the global standard for diagnostic health information” worldwide. In the US alone, the revision and its changes regarding pain have the potential to impact millions. According to CDC statistics from 2019, released in 2020, just over 20% of US adults had chronic pain and, of those, about 7% of adults had chronic pain that often limited life or work activities in the previous 3 months (known as high-impact chronic pain).¹ Most likely to be affected were adults aged 65 and older, as both chronic pain and high-impact chronic pain increase with age.

The new ICD classification regarding pain conditions was created in collaboration with WHO and a working group of the International Association for the Study of Pain (IASP) dating back several years (IASP Task Force member Joachim Scholz, MD shared the background) with Practical Pain Management (PPM) in 2019.

ICD-11 Chronic Pain Changes to Improve Pain Practice

Pain specialists applaud the ICD-11 changes. In addition to the new single diagnostic code, along with codes for pain secondary to other issues, another plus is that the revision “takes into account not only the intensity of the pain but also pain-related disability and distress,” says Jeff Gudin, MD, a pain specialist at the University of Miami and co-editor-at-large of PPM. The new classification more officially recognizes the psychosocial factors that contribute to the experience of pain – something the pain management community has known and advocated for, for years.

Dr. Gudin pointed to important field testing of the updated coding system, published in the February 2022 issue of Pain. Researchers from Germany and Switzerland trained 177 healthcare professionals across WHO regions on the ICD-11 chronic pain codes approved by the World Health Assembly in 2019 (the same codes that took effect January 2022). They evaluated 18 diagnostic codes of the ICD-11 and 12 case vignettes that described chronic pain conditions. The researchers analyzed correctness, ambiguity, and perceived difficulty of coding, comparing ICD-11 to the ICD-10, which took effect in 2015. Their conclusion: “From a coding perspective, the ICD-11 is superior to the ICD-10 in every respect, offering better accuracy, less ambiguity, and other benefits.”³

Jeffrey Fudin, PharmD, FCCP, FASHP, FFSMB, president of Remitigate LLC and co-editor-at-large for PPM, agrees that the ICD-11 coding system will change diagnosis and treatment greatly.“The diagnosis reflected in the record will be more comprehensive and accurate, and treatment may be better guided based on causality.”

Stigma around long-term opioid therapy could be affected as well, he says. “For example, it might be more obvious at a quick glance that a patient receiving long-term opioid therapy has a diagnosis that cannot be readily treated without opioid therapy. A good example is recurrent pancreatitis, which often requires intermittent or chronic opioid therapy while other visceral pain syndromes do not. This could help soften the stigma associated with long-term opioid therapy.”

What the ICD-11 Change Means for Pain Practitioners

As pain management physicians and their coders learn the ICD-11 system, Dr. Fudin suggests that “it is important that they take the few extra minutes to accurately select the accurate diagnoses and sub-diagnoses so that data mining is accurate and reflective of the patient’s real problem.”

For instance, he says, “if a patient has a diagnosis of diabetes type II, bilateral lower extremity neuropathy, and previous history of colon cancer with chemotherapy treatment, it is important to identify the underlying cause of the neuropathy. If the A1C is normal and the patient’s glucose is well-controlled, it should be obvious at a quick glance from a clinician that the neuropathy is probably from something else, perhaps chemotherapy-induced neuropathy such as platinum-based treatment.”

Approaching the conversation in this way, Dr. Fudin says, “could help guide the conversation when interviewing a patient and makes for a more accurate record.”

What will the new system mean for people with chronic pain disorders? Both clinicians agree that the new coding schema should help the accuracy of their medical problem list. More specific pain diagnoses may also facilitate insurance approval and decrease denials for both routine and specialized pain care, they add.

For more perspective, see the full IASP report on chronic pain.