ICD-11 and the new Procedure Based Classification (PBC)
ICD-11 and the new Procedure Based Classification (PBC) are used to classify patient episodes according to diagnosis or procedure, for performance management, reporting, remuneration, and also population health and public health planning.
The United Kingdom has a long history of using the International Classification of Diseases and revisions and as a World Health Organization (WHO) Member State has a mandatory obligation to collect and submit ICD morbidity and mortality data to the WHO for the production of international statistical and epidemiological data (WHO Nomenclature Regulations).
WHO’s constitution mandates to establish and revise as necessary international nomenclatures of diseases, of causes of death and of public health practices, and requests Member States to submit annual reports on health status and actions taken to improve health.
Accurate and timely data are an essential resource for Member States to achieve the Sustainable Development Goal (SDGs) targets and goals for Universal Healthcare Coverage (UHC), health emergencies and healthier populations. WHO is the steward and custodian for monitoring the health-related SDGs. Data are needed to measure performance, improve programme decisions and increase accountability.
For this purpose, WHO sets and maintains data collection standards that are needed by Member States, including the WHO Family of International Classifications that include the ICD as well as the International Classification of Functioning, Disability and Health (ICF) and the International Classification of Procedures (ICHI) under development
Morbidity statistics: ICD is a mandated NHS Standard (SCCI0021) published under Section 250 of the Health and Social Care Act 2012 to code the diagnoses of all inpatient episodes and day cases to support several data collections including Admitted Patient Care Commissioning Data Sets, Central Returns and Secondary Uses Service. ICD is a vital component of national data sets, such as Hospital Episodes Statistics (HES) in England, Hospital In-patient Statistics (HIS) in Northern Ireland, Patient Episode Data for Wales (PEDW), Scottish Morbidity Records (SMR), Cancer Registries, National Service Frameworks, Care Pathways, Performance Indicators, Commissioning Data Sets (CDS) and other Central Returns.
In England, ICD codes underpin the Healthcare Resource Groups (HRGs), to generate diagnoses-driven HRGs. The National Casemix Office (NCO) designs and refines the classifications used to describe NHS healthcare activity in England. These classifications underpin the national reimbursement system from costing through to payment and support local commissioning and performance management. NHS managers and health care professionals in secondary care also use it locally to support operational or strategic planning and performance management.
More information on the National Casemix Office and HRG tools are available.
Maps from SNOMED CT to ICD-10 are currently provided to suppliers and technical professionals to incorporate the business rules for consistent code selection and sequencing into NHS patient administration and other systems to support Commissioning Data Sets, Central Returns and support the derivation of classifications from clinical records. There are four types of map, two of which may be automated for routine hospital activity, the other two types of map support the coding of complex activity and require manual intervention by coding experts. Utilisation and the opportunity for derivation of classifications for semi-automation is dependent on the maturity of the local clinical system and comprehensive, quality structured clinical information recorded in the system.
ICD updates are currently implemented on a three yearly cycle as determined by the Department of Health and Social Care.
Plans for future
The WHO launched the latest revision (ICD-11) which was released on 18 June 2018. This release is described as an advance preview that will allow countries to start building transition plans for implementation, prepare translations, and train health professionals all over the country. The priority for WHO was to provide ICD-11 for Mortality and Morbidity Statistics referred to as ICD-11-MMS.
The WHO Executive Board (EB 144) will receive a summary report in January 2019 on ICD-11 recommending ICD-11 submission to the World Health Assembly (May 2019) for adoption to come into effect on 1-Jan-2022. WHO expectation is that Member States will start reporting thereafter in ICD-11 but recognise the actual implementation date for each Member State will vary.
In England, ICD-10 is used in secondary care, and each NHS organisation must dedicate resources to review relevant clinical notes and patient histories and assign the appropriate ICD-10 codes. NHS Digital will provide guidance and business rules to support appropriate allocation of patient episodes to the appropriate codes which are subsequently used for remuneration under the Payment by Results (PbR) mechanism.
In planning for ICD-11, we need to recognise that ICD-10 code derivation from clinical notes and patient histories is a significant investment for many providers. In addition, uptake of SNOMED CT will add additional burden to upskill clinical coders, who will also then need to upgrade their knowledge of ICD-10 to ICD-11. We expect that this would represent a very expensive exercise, as it would require significant investment in training, upskilling, and also a significantly increased workload for clinical coders initially.
In considering the vision of a “learning ecosystem” it is important to aim for a future state where the majority of ICD-11 codes are derived from SNOMED CT codes that the health care practitioners have entered into the provider system, can link to patient history from a multitude of systems, and is supported by innovative technologies (for example natural language processing, Artificial Intelligence, etc) to automate as much the ICD-11 code derivation as possible.
We have yet to determine whether the derivation of ICD-11 codes would take place at the provider site or done centrally. It is clear that regardless of where the derivation takes place, the provider clinical coders will be key in ensuring the data quality of the derivations, in particular where the confidence of derivation is low.
An indicative roadmap for ICD-11 is shown in the Indicative roadmap for ICD-11 and the new PBC standard, found below, combined with the new Procedure Classification Standard. The key points to note on the roadmap are:
- Providing maps from SNOMED CT to ICD-11 to enable local use and derivation where it exists already or is part of local plans to derive ICD.
- ICD-11 migration will likely happen after the uptake of SNOMED CT by NHS providers has reached a “critical mass”.
- ICD-11 migration will be predominantly driven by the automatic derivation of the majority of ICD-11 codes, with quality assurance and resolution of low confidence derivations by the provider clinical coding experts.
- Initially, ICD-11 derivation will take place at the provider systems. We believe that as the technology and collaborative working practices improve in the NHS, the end-state of the ICD-11 migration will be that most derivation takes place in NHS Digital, with collaborative efforts from provider clinical coders for QA purposes and resolution of low confidence derivations.
- ICD-11 will be the basis for HRG derivation until the point that HRGs can reliably link to SNOMED CT coding.
- ICD-11 will continue to be the format for reporting to WHO.
- We will work with the Research community and Public Health England to determine whether secondary uses flows could be augmented with increased granularity, as SNOMED CT level data would be available. We are sensitive to the needs to maintain historical compatibility, and we would explore a number of options to allow the transition to more granular data.
ICD is embedded in secondary care hospitals as part of the Patient Administration Systems. The implementation date of ICD-11 will depend on:
- proper assessment of the impact on official health statistics
- availability of maps from SNOMED CT to ICD-11 to support semi-automatic derivation of ICD-11, dependent on the maturity of local EPR systems
- impact assessment on workforce transformation and supplier implementation, and to be conditional on the solution of any outstanding issues
Availability of links from SNOMED CT to ICD-11 to support derivation of ICD-11 dependent on the maturity of local EPR systems. Maps from SNOMED CT to OPCS-4 are currently provided to the NHS to support the derivation of classifications. This supports the semi-automation for routine hospital activity and manual intervention by coding experts for the complex activities. Utilisation is dependent on the maturity of the local electronic health record and extent and quality of clinical information provided in the electronic record.
Availability of the National Terminology Server which could carry out the SNOMED CT to ICD-11 derivation centrally via APIs from the local EPR systems.
Additional improvements that we will aim to deliver along with the introduction of ICD-11are:
- capture advances in health science and medical practice
- maintain Core classification features of jointly exhaustive and mutually exclusive and residual categories
- new chapters to better identify: conditions to sexual health, sleep-wake disorders, traditional medicine, disorders of immune system
- better use of the digital revolution - improved incorporation into electronic environments
- coding, browsing, translation, mapping and proposal online tools; remove dependency on paper-based publications
- improved usability that requires less training
- better links from SNOMED CT to support derivation of ICD-11 dependent on the maturity of local EPR systems
Indicative roadmap for ICD-11 and the new PBC standard
ICD-11 and new Procedure Based Classification Standard
Phase 1: sharing and linking
- ICD-11 published by WHO
- SNOMED CT to ICD-11 maps using computational algorithms as a starting point
- ICD-11 and OPCS-4 and maps (from SNOMED CT) are part of National Terminology Server
- AI framework published for deriving ICD-11 codes from SNOMED CT
- OPCS-4 replacement recommendation published and consulted on
- Pilot ICD-11 derivation from SNOMED CT using AI
- CDS modified to allow SNOMED CT returns
- Consultation with NHS on other use-cases requiring ICD-11 and OPCS-4
- Comparative analysis and testing of SNOMED CT returns instead of OPCS-4/ICD-10
Phase 2: optimising and augmenting
- New Procedure Based Classifications design/config and population complete
- Proof of concept for ICD-10 derived from SNOMED CT returns
- Parallel run of new PBC/ICD-11 and HRG
- Proof of concept for new Procedure Based Classification use from SNOMED CT returns
- Publish new DCB standard for PBC/ICD-11
- NHS switches from OPCS-4 to SNOMED CT returns
- Migrate to ICD-11 for HRG, research and public health flows
- Pilot and dual run HRG using SNOMED CT
- Switch to PBC is live
- HRG using SNOMED CT is live