Additional information including, Disease Prevalence Report, Raw Data, Background Quality Report, Quality Assessment of Administrative Data can is available at the following link: Additional Information
Contact Details
Information & Analysis Directorate, Department of Health, Annexe 2, Castle Buildings, Stormont Estate, Belfast, BT4 3SQ Telephone: 028 9052 2160 E-mail: qofdataenquiries@health-ni.gov.uk
We welcome feedback on any aspects of these statistics. Comments and feedback can be sent to Laura Baird at the following e-mail address. Email: laura.baird@health-ni.gov.uk
Introduction & Background
Prevalence is a measure of the frequency of a disease or health condition in a population at a particular point in time. This bulletin presents the latest prevalence statistics for those diseases and conditions specified in the 2025/26 Clinical Care Domain (CCD) of the NI Contract Assurance Framework (NICAF), as recorded by General Practices in Northern Ireland at 31st March 2026.
Quality and Outcomes Framework
With the introduction of the General Medical Services contract in April 2004, a quality framework of indicators was developed for General Practice, the Quality and Outcomes Framework (QOF). An integral part of the QOF was the collection of prevalence data to allow practices to case find those patients that require specific management. QOF has now ceased in Northern Ireland. QOF and a number of Enhanced Services have been replaced by the CCD of the NICAF, under which, all General Practices are still required to undertake activity that would have been undertaken as part of QOF and Enhanced Services, as clinically appropriate. In order to do so, General Practices will continue to maintain disease registers, allowing prevalence data to continue to be collected.
Data Source
The data source for the disease registers data is the General Practice Intelligence Platform (GPIP)/QOF. GPIP/QOF is a joint undertaking between the Strategic Planning and Performance Group, Department of Health (DoH) and the Business Services Organisation (BSO) as an internal solution to replace the Payment Calculation Analysis System (PCAS). The application of standardised coding across General Practices, ensures consistency in prevalence data collection.
Note GPIP/QOF, like its predecessor PCAS, is an aggregated accredited practice level dataset; patient level data does not leave the general practice as part of this dataset. Each individual general practice dataset consists of individual disease register counts; it is therefore not possible to disaggregate the registers by age and/or gender, and co-morbidity cannot be determined. It is important to distinguish GPIP/QOF from GPIP. GPIP has been developed by SPPG as part of Digital Health & Care NI (DHCNI) to extract primary care data from all GP practices in Northern Ireland under agreed governance processes. GPIP is an anonymised patient level single data storage solution and as such allows more detailed disaggregation of data such as age, gender and presence of multiple conditions.
Raw Prevalence Rates
There are a total of 14 individual areas that can be used to calculate the prevalence of conditions within the population. The prevalence statistics presented in this bulletin are raw prevalence rates. This means that they take no account of differences between populations in terms of their age or gender profiles, or other factors that influence the prevalence of health conditions. The calculated rate is simply the total number of patients on the disease register (at 31st March 2026), expressed as a proportion of the total number of patients registered with a practice (at 1st January 2026). As such, care should be taken when looking at trends in prevalence over time, by practice or across geographic areas.
Interpretation of the prevalence figures included in this bulletin and some key limitations
Prevalence is a measure of the frequency of a disease or health condition in a population at a particular point in time (this differs to incidence, which is a measure of the number of newly diagnosed cases within a particular time period).
Given that QOF has now ceased in Northern Ireland, the registers will be referred to as GPIP/QOF Disease Registers, based on the system in which they are collected. These registers do not necessarily equate to prevalence as may be defined by epidemiologists and prevalence figures based on these registers may differ from prevalence figures from other sources due to coding or definitional issues. The asthma register, for example, excludes patients who have not been prescribed asthma-related drugs in the previous twelve months. Care should be taken to understand definitional differences, e.g. when comparing GPIP/QOF prevalence with expected prevalence rates using public health models.
GPIP/QOF Disease Prevalence data are collected centrally at General Practice level. There are no centrally held data on patient details that can be directly linked to the prevalence registers, so the registers cannot be analysed by patient characteristics such as age or gender. The collection of the disease prevalence data at an aggregate level for each General Practice also precludes robust analysis of co-morbidity. Many patients are likely to suffer from co-morbidity, i.e. they are diagnosed with more than one condition, but this cannot be analysed due to the lack of patient level data.
Data from registers should be treated with caution in the first few years of reporting, as they are still being established and validated. Apparent increases in prevalence may be due to improvement in recording and case finding by GPs, rather than a true increase in the prevalence in the population. Year-on-year changes in the size of disease registers are influenced by various factors including changes in prevalence of the condition within the population; demographic changes, such as an ageing population; improvements in case finding by practices; and changes to the definition of the registers (time series trends provided in this bulletin are only presented for years in which there is a consistent definition).
Detailed disease prevalence data for Northern Ireland, can be found here , with data available at GP practice, LCG and GP Federation levels. Northern Ireland level data is available from 2004/05. Historical data is also included on now-closed registers.
Where can I find information on Disease Prevalence across the UK?
Please note that diseases/clinical areas may differ across the UK and there may be definitional differences between countries for diseases/clinical areas.
Official Statistics for Cancer Prevalence in Northern Ireland are also available from the Northern Ireland Cancer Registry. These will differ from the figures presented in this bulletin. For example, the GPIP/QOF prevalence figures exclude non-melanotic skin cancers, and the register excludes patients diagnosed prior to 1st April 2003.