This ACG System FAQ page aims to provide answers to some common questions about data, security and information governance relating to the Johns Hopkins Healthcare Adjusted Clinical Groups® (ACG®) System. This information is aimed at GP practices, CCGs, Integrated Care Systems or CSUs.
What is the ACG System?
The ACG System is a decision support system developed by the Johns Hopkins Bloomberg School of Public Health and has been used in the UK NHS since 2009.
It is a person-focused case-mix system that captures the multidimensional nature of an individual’s health. It considers the total disease experience of each patient, including the implications of co‑occurring disease, encouraging a holistic view of the patient rather than the management of specific diseases or episodes. A disease-based focus may miss important implications of associated co‑morbidities. Episodic approaches often focus on acute exacerbations or flare-ups, which potentially represent failures in care management.
The ACG System as software essentially does four things:
- Stratifies a population by the risk associated with their current morbidity burden and expected resource use – the ‘Kaiser Pyramid’.
- Maps people and their diseases to different diagnostic groups to facilitate disease profiling.
- Predicts patients who are likely to be high risk and/or high cost in the coming year.
- Creates a profile for every patient based on demographic, diagnostic and pharmacy data. This includes a series of markers unique to the ACG System. These can be combined with other data from Sollis Clarity related to patients, such as resource use in secondary care (and community care, adult social care and mental health care, where available) and cost.
Who uses the ACG System?
Initially the primary use of the ACG System in the NHS was to use the predictive models to identify patients at risk of an emergency admission. GP practices continue to use it in this way but they are also now using it to identify other cohorts of patients who fit the criteria for different types care programmes.
CCGs have increasingly used the ACG System to support service planning and review, and this has now become the primary use of the ACG System in the NHS. GP practices must give their permission for an anonymised version of primary care data to be regularly extracted from their practice systems in order to enable CCGs to use the ACG System for commissioning support activities.
What data is used in the ACG System?
The ACG System uses a defined subset of data from each of four datasets: admissions, accident and emergency attendances, outpatient appointments, and GP systems.
What data, specifically, is included from GP systems?
Information from the last 12 months on all Read-coded diagnoses, prescribing and encounters, and information from any point in time for a defined set of long-term conditions.
How is the GP system data extracted?
It depends on the GP system, but generally, data is extracted on a monthly basis.
For EMIS Web users there is an automated extract that is sent from EMIS servers to a secure data centre (via N3). GP practices must activate an electronic data sharing agreement with EMIS for automated extraction.
Data can be extracted automatically from INPS Vision GP systems using Apollo software, and transferred to a secure data centre.
GPs can extract data from TPP System One using MIQUEST queries supplied by Sollis. The MIQUEST responses are then sent directly to the secure data centre for upload into Sollis Clarity and the ACG System.
All extracts meet information governance (IG) requirements.
What is the quality of the data used?
The highest value dataset used in ACGs is the GP system data because it is the most complete and accurate source of diagnosis information. Much of the value in the ACG System comes from the combination of the GP system data on diagnosis, with the secondary care datasets for activity and cost; in these respects, those datasets are generally well-coded.
How timely is the data?
The GP system data is as up to date as the last extract, so may be only a week or so old following processing. The secondary care data can be six weeks or more behind real‑time due to the time it takes to be processed and validated through national SUS data mechanisms. GP practices typically extract data on a monthly basis, although it could also be extracted weekly.
What happens to the data?
All data is transferred via the NHS N3 secure network and processed in a secure data centre. The processed data remains in the data centre and is accessed either at a non-patient-identifiable level (commissioners) or a patient-identifiable level (practices) according to a strictly controlled access model. Patient-identifiable level access can only be granted by the GP practice to which that data relates.
What are the benefits of using the ACG System?
The intelligence derived from the ACG System, particularly when combined with other data, enables commissioners and clinicians to:
- Profile the health needs of local populations to support commissioning and service redesign activities.
- Profile disease and morbidity burden across a population to support public health and planning activities.
- Make comparisons across a locality or CCG that take into account differences in case-mix between GP practices. For example, case-mix adjusted comparisons could be made on the prevalence of particular diseases or utilisation measures, such as prescribing or emergency admission rates.
- Identify high-risk individuals for inclusion in care management programmes that can help reduce adverse outcomes (for example, unnecessary emergency admissions).
- Identify people at lower levels of the risk pyramid who may be suitable for other care programmes offered within primary care.
Why is it necessary to extract and hold patient-identifiable data?
Identifiable data (NHS number only – no patient named data is extracted or held) is required for dataset linkage and for practice-level access to the ACG data in order for practices to be able to identify individuals. Data is held in a central repository and accessed remotely according to role and appropriate access level. Practice level access includes NHS numbers, commissioner level access does not.
Does the data used by the ACG System comply with NHS information governance rules?
Yes. The data processed by Sollis Clarity and the ACG System conforms to NHS Confidentiality Advisory Group (CAG) guidance, including consent and dissent codes and confidentiality guidance, and excludes data with sensitive Read codes.
Data sharing agreements are set up with each GP practice to ensure there is a clear understanding of what data is extracted and processed and for what purpose.
In 2011, for example, the (as then) NHS South Central ACG System process was presented to the National Information Governance Board (NIGB), who acknowledged that the project was taking reasonable steps to ensure that patient confidentiality is not breached. Local medical committees were also consulted and are satisfied with the IG processes that have been put in place.
Sollis is on the NHS list of approved suppliers.
Do GPs need explicit consent from their patients to use their data in ACG processing?
No. NHS England states that provided patients are being generally informed through normal channels of communication, such as practice information leaflets and posters, about the potential use of their data for projects such as the ACG System (including information on how they could opt out if they so wished), then individual consent is not necessary.
How do I opt out the patients who don’t wish for their data to be used?
GP practices can use patient dissent Read codes to exclude patient data from being extracted from the GP system.
Do I need to change any wording in my practice’s patient information leaflets, posters or website to ensure it reflects this use of patient data?
You may need to; this relates closely to the IG Toolkit requirements for General Practice. Requirement 10-213 states that GP Practices should ensure that… “There is a publicly available and easy to understand information leaflet that informs patients/service users how their information is used, who may have access to that information, and their own rights to see and obtain copies of their records.”
While it would not be appropriate to be prescriptive to practices about their patient information leaflet wording, it may be helpful to consider the following sample statements that cover the two fundamental aspects of the ACG System (patient level and population level), in considering your patient information:
- Patient information may be used by the GP practice to help us identify specific patients who may be at risk of certain events (for example, admission to hospital, or developing a disease), in order to help us try to prevent such events, where possible.
- Patient information in anonymised form (where it is not possible to identify any individual patient) may be used by the GP practice to help us plan services for our patients and the wider health community.
If your patient information leaflet describes generically how your patients’ data may be used, it does not need to make specific reference to the ACG System (due to the number of potential uses of patients’ data, it would not be practical to list them exhaustively).
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If you have any questions about the ACG System, please contact us. Alternatively, download the Johns Hopkins University’s white paper, Applications of the ACG System in the UK.
Sollis Clarity is the largest solution deploying the ACG System in the UK.
