Ep. 168: Making Sense of the New ICD-11 Classification of Chronic Pain - From Concept to Clinical Practice

00:00:00: Welcome to EANcast, your weekly source for education, research and updates from the European Academy of Neurology.

00:00:16: Hello and welcome everyone to the EANcast weekly neurology.

00:00:21: My name is Oksana Grosso and I am a neurologist from the Republic of Moldova.

00:00:25: This month's topic is pain and today's episode we will talk about the new classification of the chronic pain.

00:00:33: My guest today is Professor Rolf Tridi.

00:00:36: Professor Tridi is a retired professor of neurophysiology and deputy managing director of the Mannheim Center for Translational Neuroscience in Germany.

00:00:46: He is also the former president of the International Association for the Study of Pain and the chair of the working group that developed the ICD-Ileven classification of chronic pain.

00:00:57: Welcome, Professor Tridi and thank you for joining us.

00:01:01: Well, welcome Oksana and thank you very much for your interest.

00:01:06: We will discuss an important topic, the new ICD-Eleven classification on chronic pain.

00:01:12: Why we consider this topic important to be discussed?

00:01:16: I think because for many years, pain, including chronic pain, was regarded simply as a symptom of another condition, another disease.

00:01:25: But in ICD-Eleven, which was published by the World Health Organization in the year two thousand nineteen, chronic pain is recognized for the first time as a disease in its own right.

00:01:37: This is a fundamental change.

00:01:39: It acknowledged the fact that chronic pain is not only widespread, but also has a huge impact on quality of life, mental health and social functioning.

00:01:49: So, let's begin with the basic.

00:01:52: Dear Professor Tridi, please tell us why he was a new classification of chronic pain needed.

00:01:59: I think it's obvious to everybody that medicine needs classification for many purposes.

00:02:04: Recording data, making progress in research, but also for reimbursement purposes.

00:02:10: In the currently still widely used ICD-TEN, the TENS version of ICD, there is no adequate representation of chronic pain.

00:02:18: And at the time in two thousand twelve when we approached WHO, I had been working on neuropathic pain.

00:02:25: And for neuropathic pain, we know the underlying condition is in neurological disorder or some damage to the central nervous system.

00:02:33: But it's affecting only a certain percentage of patients.

00:02:37: So the neurological diagnosis does not tell you whether these people suffer from pain or not.

00:02:42: And when they do, quality of life is miserable, prognosis is worse.

00:02:46: So definitely in this field that I was working on, there was a definite need to change something.

00:02:52: We were then inspired by the classification of headaches.

00:02:56: This was just odescent towards Jensen from Denmark, from the Headache Society and the International Association for the Study of Pain.

00:03:05: They had mentioned that really the field of headache advanced a lot when migraine was defined as a headache disorder, disease in its own right.

00:03:12: And this is called chronic primary headache.

00:03:16: So we then set out and said, okay, let us define chronic primary pain.

00:03:21: versus chronic secondary pain.

00:03:24: And this is what this committee actually ended up doing.

00:03:28: Very interesting.

00:03:29: And there is a special organization of chronic pain in the ICD-Eleven.

00:03:35: It's something that stands out from the other classifications.

00:03:41: Yeah.

00:03:42: So we basically try to follow the classification principles of the new ICD-Eleven, the eleventh version as closely as possible.

00:03:51: And so we started out as a first category with a new category of chronic primary pain.

00:03:58: So since it's new, you don't know what that is.

00:04:01: So what it summarizes is, among other things, the primary headaches are cross-reference from that.

00:04:07: Then we have fibromyalgia syndrome as a very important chronic primary pain condition.

00:04:13: And later complex regional pain syndrome was also shifted there.

00:04:17: And then there is a large number of other chronic primary pain conditions that is perceived in different organ systems.

00:04:24: It could be musculoskeletal, chronic widespread pains of unknown origin.

00:04:28: It could be some visceral pains like irritable bowel syndrome, bladder pain syndrome, and so on.

00:04:34: So it's a relatively large group of chronic primary pains where there is no underlying condition, but really the chronic pain is the disease in itself.

00:04:46: While pain specialists had been considering this idea for a long time, other fields of medicine were a bit reluctant to accept this.

00:04:54: Therefore, it's equally important that we introduced concepts of chronic secondary pain.

00:05:00: For example, the musculoskeletal health people ask us, do you now think all chronic musculoskeletal pains are primary?

00:05:07: And we said no, because there's also chronic secondary musculoskeletal pain.

00:05:12: When we know it's, for example, due to an atherosis, an inflammatory condition and so on.

00:05:18: Likewise, chronic visceral pain, so we know the underlying chronic disease, like the inflammatory bowel diseases that cause chronic pain condition.

00:05:29: And neuropathic pain is also in this category.

00:05:32: It's a chronic secondary pain condition where it is secondary to a neurological disease.

00:05:39: So we have a certain mirror image situation that very often we have chronic primary pain conditions and chronic secondary pain conditions in similar organisms where they are perceived.

00:05:54: And this is intentional because it's supposed to be differential diagnosis.

00:05:59: And the differential diagnosis is not necessarily easy.

00:06:04: That's one aspect.

00:06:06: The other aspect is that for underlying causes, cancer and trauma are major known causes for chronic pain conditions.

00:06:15: And these had not been reflected at all.

00:06:18: So we introduced the concept of chronic pain due to cancer or its treatment.

00:06:25: And chronic pain due to either surgery or other type of trauma.

00:06:29: And I think I don't have to explain the relevance of that.

00:06:32: So we know, in particular, since more and more people fortunately survive cancer treatment, the cancer then is turned into a chronic condition.

00:06:41: And either the cancer itself or the treatment, chemotherapy, radiotherapy, surgery and such cause chronic pain conditions.

00:06:51: One of the new aspects of ICD-Eleven is that the codes are much more complex.

00:06:57: So codes usually are combined with extension codes.

00:07:00: And for example, for chronic cancer pain, one would have to specify, as the underlying condition has, as the causing condition, what type of cancer it is.

00:07:10: Or for neuropathy pain, what type of neurological disorder.

00:07:15: The reverse can also be programmed.

00:07:16: For example, for cancers, For a few years now, ICD-Eleven contains a link.

00:07:22: Cancer may have a manifestation of chronic cancer-related pain.

00:07:27: And you can see the implications.

00:07:29: I don't think I have to read the classification because it's relatively easy to find it.

00:07:34: You look for the ICD-Eleven browser or even better for the ICD-Eleven coding tool.

00:07:41: And you can do that in many, many languages.

00:07:44: And then you can type in the condition that you're looking for and then you are brought directly into the classification.

00:07:54: Thank you, professor.

00:07:55: Do you think that this new classification will change the way that doctors approach patients in their daily clinical practice?

00:08:05: Before we were allowed to put this classification into the WHO system, WHO required field trials.

00:08:14: They are not happy to just have a consensus among experts or something might be useful.

00:08:19: They want to see evidence.

00:08:20: So we performed a number of future trials and there are other studies still ongoing.

00:08:26: The very first one was a multi-center trial in Japan several European countries and probably I forgot someone and they were just taking consecutive cases and used The seven major categories that we had primary pain and then six categories of secondary pain, which is cancer related, trauma related, neuropathic, musculoskeletal visceral.

00:08:50: And then we also have the headaches as cross reference.

00:08:52: And it turned out that completeness and uniqueness were actually provided by this.

00:09:00: And later field trials compared the existing ICD-Tender people knew with the new.

00:09:07: tool ICD-Eleven and interesting.

00:09:10: usually users find ICD-Eleven easier and this even includes professional coders.

00:09:17: This has been a study in Germany that I was quite surprised to see.

00:09:21: They went through all the chapters of ICD-Eleven and also they took the time it takes to use it and the new system may look a little bit difficult but actually in practice it's easy because it has a full electronic support.

00:09:37: And that's what the autism was missing.

00:09:41: Yeah, thank you.

00:09:42: And in my clinical practice, I use it a lot.

00:09:45: It helps me to explain the patients what kind of pain they have and to explain the colleagues that there is something real and should be taken into consideration and coded, put there on the paper.

00:09:59: So the next question will be, Dear Professor Tridi, Do you think this classification, the new one that already has some years, but it's not implemented in the clinical practice, would change something in our way that we do research or in our health policy in developed and not so developed countries?

00:10:21: Well, maybe since you mentioned clinical practice, so all member states of the World Health Organization had approved of moving from ICD-Tent to ICD-Eleven.

00:10:33: but most countries have not done so.

00:10:36: So lower income countries who have not had a very developed healthcare information system were happy to use a model system provided by WHO and they are implementing the new classification and they're reporting that.

00:10:50: really documentation all the way down to reimbursement is much easier with this.

00:10:54: Countries like mine in Germany who have a very complex system are very reluctant to change anything.

00:11:01: And therefore in many places of the world it is not yet implemented.

00:11:06: And here I think the approach is that you would like to have precise medical information on all patients and our current coding systems do not provide that because they're biased by the reimbursement system that they feed into.

00:11:25: So anything that is not reimbursed is not going to be coded.

00:11:29: It's also an experience that colleagues in Thailand made.

00:11:32: So they analyzed both inpatient and outpatient cases for a year in each case.

00:11:37: Notice that ICD-Eleven gives a much clearer separation.

00:11:41: For example, they treat lots of cancer patients and they just had chronic pain somewhere and were not differentiated from let's say chronic back pain patients.

00:11:52: However, in Thailand, they don't have reimbursement.

00:11:57: to identify these patients or not may improve their treatment provided they have enough volunteers willing to do so, but it's not really changing the health care system.

00:12:06: So clearly visibility for the health care system in an official coding system is going to be very important.

00:12:14: And then I learned this relatively recently from a German institution that does the coding.

00:12:22: If you have a code that identifies a diagnosis, that's fine.

00:12:26: But you also need a call for the treatment.

00:12:29: And in our circles, we have evidence that a multimodal approach usually is the best probably across the board.

00:12:38: So medications alone are not sufficient.

00:12:41: Very often we need physiotherapy.

00:12:43: We need some types of psychotherapy.

00:12:44: We need to properly go into the either working condition or living conditions at home.

00:12:52: in order to really change management on the ground.

00:12:55: There needs to be reimbursement code for this type of a treatment.

00:13:00: In Germany we have such a code and therefore what we needed was triggers and therefore with triggering diagnosis and a reimbursement code this is what's working.

00:13:10: So I think what is needed to change health policy is in addition to enhancing the visibility.

00:13:18: I think it's necessary to do advocacy work for the reimbursement of multimodal approaches.

00:13:24: And they have been proven to be cost effective.

00:13:27: So in theory, it should work.

00:13:29: Yeah.

00:13:30: And what about the research?

00:13:32: Yeah, for research, it's similar that you have to define what your research is about.

00:13:38: And then the funding agencies have certain classifications where they put the funding.

00:13:45: So these entities need to be codable.

00:13:47: And the IC-Eleven coding permits researchers to specify what the research is about.

00:13:56: research chronic pain.

00:13:57: For example, in my animal research work, we are studying chronic primary musculoskeletal pain, something that does not exist in ICD-TEN, but interesting enough, the agency in my state in Germany that has to check whether I'm permitted to do these things has used or has switched to using ICD-ELEVEN right away, because there's no complex reimbursement system linked to this.

00:14:25: So they said, okay, that's a new coding system.

00:14:28: And therefore in my research, I can specify this.

00:14:31: And if other countries permit the same thing, then you can find patterns in research that there are several groups, let's say from psychology, from neurology, from mental health, from orthopedics, that actually work on similar topics.

00:14:47: And then this might actually create a focus also for research learning.

00:14:53: But definitely for reporting, I think it provides us a good opportunity to specify what's the condition that we're talking about.

00:15:02: Thank you, Professor Tridi.

00:15:04: You told us already about the importance of the classification in coding, research, clinical practice, but as I know, there is a new mechanism that was proposed with this classification.

00:15:18: Can you tell us more?

00:15:20: A little bit.

00:15:22: I know what you're alluding to.

00:15:23: It was a plastic pain.

00:15:24: It was actually not introduced with this classification.

00:15:28: The IISP had two committees.

00:15:30: One was on terminology, and the other was on classification.

00:15:34: And we had cross links.

00:15:35: And in the terminology task, because there are other people who are also concerned about what is fibromyalgia.

00:15:43: And at that time, IISP had defined neuropathic pain.

00:15:49: as chronic pain due to damage to the somatosensory system by lesion or disease.

00:15:56: And then since neuropathic pain was defined, one had to find a term for the non-neuropathic pain, which is nociceptive pain.

00:16:05: So if you injure yourself, it's a nociceptive pain.

00:16:07: If you have a chronic inflammation, it's a nociceptive pain.

00:16:09: So these two terms existed.

00:16:13: Then the fibromyalgia experts wanted to have a term to apply to their patients.

00:16:22: And they were not happy with something that we had suggested.

00:16:25: when you have two dimensions.

00:16:28: You have no suplastic gas now, you have no plastic gas now.

00:16:32: In terms of combinations, there are four combinations.

00:16:35: You can have both.

00:16:37: Many people have heard about the mixed pain concept.

00:16:39: So back pain very often is mixed, nociceptive and neuropathic.

00:16:44: And then there's also neither nor.

00:16:47: And an honest wording for that would be idiopathic.

00:16:52: These people were not happy with that, so they tried to invent a new word.

00:16:56: But I'm not a big fan of that, because if we have a third word, like nocoplastic, it means... we don't have four or three different conditions, we have two times two times two possibilities.

00:17:11: And we still have the possibility that patients are nothing above, so they might be idiopathic.

00:17:18: Before I go on to say something about non-soplastic, let's talk about idiopathic and the terminology around this.

00:17:25: So chronic primary headaches, you could say it's an idiopathic headache, you don't know where it's coming from, it's just a headache.

00:17:32: Chronic primary pain, you don't know where it's coming from.

00:17:34: It's just a chronic pain.

00:17:37: Chronic primary hypertension, same story.

00:17:41: It used to be called essential hypertension, but for many fields of medicine, there are conditions that in a way are something like symptoms.

00:17:49: We don't know where they're coming from.

00:17:51: And when there are disease, there's a word for that.

00:17:54: And the developing standard for words for this is primary.

00:17:59: So, primary hypertension.

00:18:01: Primer headaches exist already and chronic primary pain exists.

00:18:05: So that's what I'm a fan of.

00:18:08: With respect to nosoplastic pain, one more comment.

00:18:11: So the proposed definition, actually this allows combinations.

00:18:16: It says if it's fully explained with nosoceptive onopathic mechanisms, it cannot be nosoplastic.

00:18:24: And then it overlaps a lot with the concept of chronic primary pain.

00:18:29: in which case you don't need it because we have another concept for it.

00:18:32: That is much more integrated in normal medicine.

00:18:37: I could see a potential advantage because we have a lot of plasticity in the pain system all the time.

00:18:45: Whenever you injure yourself, there is plasticity for a couple of hours and then it's gone.

00:18:50: And when you have a chronic pain condition, I can't imagine any chronic pain without plasticity, although there are few cases potentially.

00:18:58: Therefore, one could imagine knows a plastic as kind of an extension code that you say, okay, I have a chronic cancer pain patient with additional evidence for plasticity.

00:19:09: That's not the current definition.

00:19:11: It's absolutely different from the current definition.

00:19:14: But if you take the word plasticity, And I'm watching the field how it develops.

00:19:20: Many people seem to use nociplastic in the sense when they feel they have evidence for some plasticity, they call it nociplastic.

00:19:27: It's not the definition.

00:19:28: They have to exclude that the plasticity is around, for example, neuropathic pain.

00:19:35: The term nociplastic is a bit difficult.

00:19:39: The term neuropathic just by coincidence is one of the categories that we have, but only because it refers to a certain type of causes.

00:19:48: And the term nociceptive is not used in ICD-Eleven.

00:19:52: For the many nociceptive paints that we have, it's just an overall term that the ISP is suggesting.

00:20:00: So in ICD-Eleven, the only term that we have of these mechanistic descriptors is neuropathic, but that is some kind of a coincidence.

00:20:11: Okay, as I understand, the debate will go on.

00:20:15: And the data driven.

00:20:17: Yeah, we'll see how it will go.

00:20:21: And if you have to leave to our listeners with one takeaway message, what would it be?

00:20:29: I think we need a motivation to move to IC-Eleven, even in countries that have very complex systems.

00:20:35: And the best motivation that I have had so far is that IC-Eleven allows a much more precise description of the actual medical condition of a patient.

00:20:46: And this is true for any chronic disease, any chronic disease that has any core abnormalities.

00:20:53: So it's not specific to just pain.

00:20:55: It applies to all chronic conditions.

00:20:58: And with that in mind, I think also in the highly developed healthcare systems, we have a good motivation to finally start using ICD-Eleven.

00:21:07: Yeah.

00:21:08: Thank you, Professor Tridi, for this excellent overview.

00:21:13: The new classification of chronic pain is clearly a milestone in our field, and we will have major implications for both patients and clinicians.

00:21:21: And thank you to our listeners to join us today for the E&Cast weekly neurology.

00:21:28: Stay tuned for our next episode.

00:21:30: We will continue exploring important developments in neurology and pain medicine.

00:21:36: See you!

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