PVFS, ME and CFS in classification and terminology systems: notes for the future

Post #355 Shortlink: https://wp.me/pKrrB-4Yv

In 2002, I set up FreeMEuk — a Yahoo Group support and information exchange for patients with ME, CFS, and for carers, like myself. In 2007, I launched ME agenda to provide patients, carers and advocates with information, resources and commentary on the political issues affecting the lives of myalgic encephalomyelitis (ME) patients in the UK.

In January 2010, I created this site specifically to monitor and report on the development of the American Psychiatric Association’s DSM-5, the development of the World Health Organization’s ICD-11 and on other classification and terminology systems. Where appropriate, I have galvanized stakeholders to participate in review and comment exercises or co-ordinated other forms of response.

Down the years, I’ve undertaken numerous short and long-term ad hoc projects, advised others on technical matters relating to classification and terminology systems, submitted and collaborated in the submission of proposals, briefed politicians and patient organizations and kept patient forums up to date with key developments.

Today I am retiring after 17 years of advocacy work.

My sites will remain online for the foreseeable future. Over the coming months I shall be carrying out some housekeeping on this site to remove or archive older, less relevant content.

Classification and terminology systems are going to need continued monitoring; where required, input from stakeholder groups — clinicians, researchers, health practitioners and professional body allies, social workers, disability lawyers and advocacy organizations will need to be co-ordinated.

Where no process for public stakeholder input currently exists, channels of direct communication will need to be opened with the agencies responsible for the development and management of these systems and collaborative dialogues established.

WHO, for example, ostensibly gives more consideration to evidence based submissions supported by rationales, international consensus and input from clinical and professional bodies — has scant regard for patient opinion and none whatsoever for petitions or mass mailings — the latter and similar types of “action” will only undermine the careful work and discourse that I and others have fostered.

All these systems will require regular monitoring:


DSM-5 published in May 2013; it has an update process which reviews formal submissions for changes to criteria, related texts, assessment measures or corrections. DSM-5 also absorbs relevant coding changes in the annual FY releases of the U.S. specific ICD-10-CM. Approved proposals are posted for a 45 day stakeholder comment period. For example, in 2015, an edit in the text for Somatic symptom disorder¹ was approved for implementation and the revised text published in the DSM-5 Update Supplement.



Member states using the WHO’s ICD-10 don’t all use the same version (or the most recent version), for example, NHS England currently mandates the use of ICD-10 Version: 2015, not Version: 2016. WHO has said that the final update to ICD-10 will be Version: 2019. This final release is understood to have been prepared but is not currently available on the ICD-10 Browser platform.


The U.S. uses ICD-10 for reporting mortality and developed a “clinical modification” of ICD-10 (called ICD-10-CM) for morbidity. A new release of ICD-10-CM is posted on the CDC website annually, in June.

There are two public NCHS/CDC Coordination and Maintenance Committee meetings a year through which proposals for changes to the ICD-10-CM can be submitted for discussion (in March and September) followed by a stakeholder comment period.

At the September 12, 2018 C & M Committee meeting, proposals for changes to the existing coding of R53.82 Chronic fatigue syndrome NOS; G93.3 Postviral fatigue syndrome, Benign myalgic encephalomyelitis; and a second option for addition of the SEID term were presented for consideration and public comment¹. Whilst no changes for these codes were approved for implementation in the FY 2020 ICD-10-CM release, this topic will need continued monitoring as it may be revisited at a future C & M Committee meeting for presentation of revised proposals.

1 ICD-10-CM Coordination and Maintenance Committee Meeting, September 11-12, 2018, Diagnosis Agenda Part 2

Other country specific clinical modifications of ICD-10:

Around 25 member states are also using a modification of the WHO’s ICD-10. For example: Canada (ICD-10-CA); Germany (ICD-10-GM); Australia (ICD-10-AM). Belgium, Luxembourg and Spain use ICD-10-CM; Ireland and Slovenia use ICD-10-AM.

Countries using modifications of ICD-10 have individual update cycles and varying policies around public stakeholder input and review. Some countries post their Tabular List and Index modifications in the public domain; others are available only under licence, for example, Australia’s ICD-10-AM isn’t publicly available. The coding, hierarchy and chapter location of the PVFS, BME and CFS terms differs between some of the clinical modifications, while others remain consistent with the structure of the WHO’s ICD-10.

This table from the eHealth DSI Semantic Knowledge Base project compiles information provided from a number of member states on their use of ICD (or a modification of ICD) and their plans regarding potential future implementation of ICD-11. Information has been provided by: Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, France, Germany, Greece, Hungary, Ireland, Italy, Luxenbourg, Malta, Netherlands, Portugal, Slovenia and Spain: Current status of the use of ICD by eHDSI deploying countries (2018)


SNOMED CT is a comprehensive clinical terminology system used in electronic patient health records. SNOMED CT maps to ICD-10 and there is a SNOMED CT to ICD-11 Mapping Project in progress.

SNOMED International has thirty-nine member countries. There is a SNOMED CT International Edition, for which two releases are issued per year (in January and July). There are a number of country specific national editions which release twice yearly updates on a staggered schedule. 12 of these national editions can be viewed on the SNOMED CT Browser platform.

SNOMED CT national editions absorb the changes in the most recent release of the International Edition but they can also include additional country specific terms. For example, the UK Edition has a unique Concept term: Medically unexplained symptoms (SCTID: 887761000000101). Prior to March 2019, the SNOMED CT Netherlands Edition had retained the term “neurasthenie” under Synonyms to Chronic fatigue syndrome, although the Concept term: Neurasthenia (SCTID: 268631001) and some associated codes had been retired from the International Edition and from all other national editions, some years ago. Following a request supported by a rationale, the term “neurasthenie” has now been removed from the Netherlands Edition.

The SNOMED CT Concept term for Chronic fatigue syndrome is SCTID 52702003 Chronic fatigue syndrome (disorder). Benign myalgic encephalomyelitis; and Myalgic encephalomyelitis are included as Synonym terms.

Following a successful submission in February 2018 for the addition of a new parent, SCTID: 52702003 Chronic fatigue syndrome (disorder) has been assigned under parent: SCTID: 118940003 Disorder of nervous system (disorder) since the July 2018 release of the SNOMED CT International Edition. This change of parent has been incorporated into the national editions.

The International Edition and the national editions of SNOMED CT will need monitoring twice yearly for changes and additions to their content.


On May 25, 2019, the 72nd World Health Assembly voted unanimously to adopt the ICD-11. The earliest date from which member states can start using the ICD-11 code sets for reporting data is January 1, 2022. Countries are beginning to evaluate the new edition and develop road maps but even early implementers are anticipated to take several years to prepare their health systems for migration. There is no mandatory implementation date and countries will transition to ICD-11 at their own pace and according to their resources and requirements. For some years to come, WHO will be accepting data reported using both ICD-10 and ICD-11 code sets.

ICD-11 update and maintenance: The current release of ICD-11 (Version 04/2019) on the Blue ICD-11 MMS platform is a stable release but an update and maintenance cycle is already in place.

The various ICD-11 Topic Advisory Groups and sub working groups, the Revision Steering Group and the Joint Task Force have all been sunsetted. WHO is now advised on how to process proposals for changes to ICD-11 by the Family of International Classifications Network (WHO-FIC); the Classifications and Statistics Advisory Committee (CSAC); the Medical and Scientific Advisory Committee (MSAC); the Mortality and Morbidity Reference Groups; and the Functioning and Disability Reference Group.

Updates that impact on international reporting (the 4 and 5-digit structure of the stem codes) will be published every five years. Updates at a more detailed level can be published at annual rates. Additions to the ICD-11 index can be done on an ongoing basis. (There are currently in the region of 1200 unprocessed proposals waiting to be processed, with new proposals being submitted daily by WHO, professional bodies and other stakeholders.)

PVFS, BME, CFS: In a decision supported by the MSAC and CSAC committees, WHO rightly rejected the proposal of Dr Tarun Dua/Topic Advisory Group Neurology to delete the G93.3 legacy terms from the Diseases of the nervous system chapter and reclassify these terms in the Symptoms, signs chapter, under Symptoms, signs or clinical findings of the musculoskeletal system.

All three terms have been retained under their legacy chapter, under parent class: Other disorders of the nervous system, with 8E49 Postviral fatigue syndrome retained as the Concept Title. Benign myalgic encephalomyelitis; and chronic fatigue syndrome are both specified as Inclusion terms. Reciprocal exclusions for MG22 Fatigue were submitted for and approved.

The Proposal Mechanism platform for ICD-11 will need constant surveillance: there are currently no unprocessed proposals pending review for PVFS, BME and CFS. To date, WHO has rejected proposals for deprecation of the word “Benign” from Benign myalgic encephalomyelitis. This will need pursuing.

BDD: A proposal submitted by a third party in April 2017 for Deletion of 6C20 Bodily distress disorder has remained under review with the CSAC committee. According to WHO admins, in June 2019: “This proposal is being sent to MSAC to ensure the precedent decision on this issue still stands. Team3 WHO 2019-Jun-12 – 16:40 UTC”

(In February 2019, my own recommendations for 6C20 Bodily distress disorder had been marked as rejected by a different WHO admin team, with the comment: “This proposal has been extensively discussed by WHO and its advisory committees. There is no new scientific evidence to support this proposal and it will not be further processed. Team 2 WHO 2019-Feb-26 – 23:04 UTC)

On December 02, 2019 I submitted a new proposal and rational for adding exclusions for PVFS; BME; and CFS under 6C20 Bodily distress disorder. The WHO approved and implemented my proposal on January 17, 2020.

For copy of my rationale in support of this new proposal see: http://bit.ly/2NL0lX5

For more information on approved and rejected proposals see: Status of ICD-11 processed proposals v5 (updated to reflect implementation of exclusions under BDD).

Clinical modifications of ICD-11:

It is understood that the WHO would prefer to limit the development of national modifications and that policies around the licensing of ICD-11 are still being formulated. Countries developing modifications of ICD-11 will need surveillance.

See post World Health Assembly adopts ICD-11: When will member states start using the new edition? for more information on country plans.

See Presentation slides #36-38 for more information on licensing and the development of country modifications: Insights into the Next Revision: Like Texas, Everything is Bigger in ICD-11, Kathy Giannangelo, RHIA, CCS, CPHIMS, FHIMA, Texas Health Information Management Association.

ICD-11 and the CDDG guideline for mental disorders:

For ICD-11, the WHO Department of Mental Health and Substance Abuse has developed the “Clinical Descriptions and Diagnostic Guidelines (CDDG) for ICD‐11 Mental, Behavioural and Neurodevelopmental Disorders” (an equivalent publication to ICD-10’s “Blue Book”).

The CDDG provides expanded clinical descriptions, essential (required) features, boundaries with other disorders and normality, differential diagnoses, additional features, culture-related features and codes for all mental and behavioural disorders commonly encountered in clinical psychiatry; it is intended for mental health professionals and for general clinical, educational and service use.

WHO has said it plans to release the CDDG “as soon as possible” after WHA’s adoption of ICD-11. But it remains unclear whether the CDDG has been finalized or if it will be released this month, later this year or next year. See this post Clinical Descriptions and Diagnostic Guidelines (CDDG) for ICD‐11 Mental, Behavioural and Neurodevelopmental Disorders for more information.

Whilst clinicians have been able to register to review and provide feedback, no draft texts for the CDDG have been made available for public stakeholder scrutiny and comment and I have not had access, for example, to the most recent draft for the clinical descriptions and diagnostic guidelines for ICD-11’s Bodily distress disorder.

ICD-11 and the ICD-11 PHC:

Also under development is the WHO’s ICD-11 PHC — a clinical guideline written in simpler language to assist non-mental health specialists, especially primary care practitioners and non medically trained health workers, and also intended for use in low resource settings and low- to middle-income countries, with the diagnosis and management of common mental disorders. It comprises 27 mental disorders and contains no other disorders or diseases. Like the ICD-10 PHC (1996), this revised diagnostic and management guideline will not be a mandatory classification for member states.

For the mandatory core ICD-11 classification, WHO is going forward with the SSD-like Bodily distress disorder (BDD).

But the ICD-11 PHC is proposed to include a disorder category called “Bodily Stress Syndrome (BSS)” that has been adapted from the Fink et al (2010) Bodily distress syndrome (BDS). See Comparison of SSD, BDD, BDS, BSS in classification systems, July 2018.

Under exclusions and differential diagnoses for BSS, certain psychiatric and general medical diagnoses have to be excluded but CFS, ME; IBS; and FM appear not to be specified as exclusions. See this post Clinical Descriptions and Diagnostic Guidelines (CDDG) for ICD‐11 Mental, Behavioural and Neurodevelopmental Disorders for more information.

It’s not known when this guideline is expected to be finalized and made available for download. The ICD-11 PHC has not been developed on a publicly accessible platform and draft texts are not available for public stakeholder review and comment. This non mandatory 27 mental disorder guideline needs close scrutiny.


The WONCA developed and WHO endorsed, International Classification of Primary Care (ICPC-2) is under revision for ICPC-3.

ICPC-2 is available in 34 countries; used in primary care in 27 countries and is mandatory in 6 EU countries, eg the Netherlands. The content of ICPC-3 will be linked to relevant classifications, such as ICD-10, ICD-11, ICF, ICHI, DSM-5, clinical terminologies such as SNOMED-CT, but also to previous versions of ICPC.

The draft content for ICPC-3 is not being developed on a publicly accessible platform and it’s unclear whether any form of stakeholder review will be undertaken or at what point.

Caveat: This ICPC-3 roadmap on an ICPC-3 Working Group platform may have been revised since it was posted: ICPC-3 Roadmap Milestones August 28, 2018.

Dr Marianne Rosendal (Aarhus University), who has published with Prof Per Fink, is the European representative on WONCA’s International Classification Committee and a member of the revision committee for ICPC-2, as is the U.S.’s, Dr Michael Klinkman. ICPC-2 meeting summary documents dating from 2010/2011 indicate that Dr Rosendal has discussed the potential for inclusion of a Bodily distress syndrome or similar disorder concept in the ICPC-3. Prof Per Fink is likely to be lobbying hard for its inclusion. The development of ICPC-3 will need very close monitoring.


Comparison of Classification and Terminology Systems, Chapman & Dimmock, July 2018

Comparison of SSD, BDD, BDS, BSS in classification systems, Chapman & Dimmock, July 2018

Post: ICD-11 implementation package, June 06, 2019

Post: World Health Assembly adopts ICD-11: When will member states start using the new edition? June 17, 2019

Post: Clinical Descriptions and Diagnostic Guidelines (CDDG) for ICD‐11 Mental, Behavioural and Neurodevelopmental Disorders, June 28, 2019

Insights into the Next Revision: Like Texas, Everything is Bigger in ICD-11, Kathy Giannangelo, RHIA, CCS, CPHIMS, FHIMA, Texas Health Information Management Association


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