DARS: products and services


A description of the data products we use to provide data extracts and other services.

DARS products available through DARS Online

Hospital Episode Statistics (HES) - Over 1 billion records of patients attending accident and emergency units, admitted for treatment or attending outpatient clinics at NHS hospitals in England.

Patient Reported Outcome Measures (PROMs) - Pre and post-operative survey data collected from patients receiving hip replacement, knee replacement, hernia and varicose vein surgery.

HES linked to PROMS - Linking PROMS to hospital inpatient episodes data from HES gives a much richer data set which provides the ability to analyse the data by patient demographics and by the extensive procedure and diagnosis information which are present in HES.

Diagnostic Imaging Data Set (DID) - Data on NHS-funded diagnostic imaging tests, such as MRI scans and x-rays, extracted from NHS providers' radiological information systems.

HES linked to DID - The linkage of HES to DID enables customers to analyse acute secondary care pathways for patients receiving diagnostic imaging tests in England. This analysis could help to identify trends and variation in patient outcomes and be used to improve services for patients.
Improving Access to Psychological Therapies Data Set (IAPT) - Adults in receipt on NHS funded psychological therapy services

Mental Health data (MHMDS, MHLDDS, MHSDS) - Includes adults in receipt of NHS funded specialist, secondary mental health or learning disability services.

HES linked to Mental Health data - The linkage between HES and MHMDS/MHLDDS/MHSDS is provided as a bridging file which enables mental health records to be matched with records in HES through a pseudonym that protects the identity of individual patients. This enables analysis of acute patient pathways for mental health service users in England, which could be used to assess equality of access or identify opportunities for service improvement.

NHS Registration Data from the Personal Demographics Service - The Personal Demographics Service (PDS) is the national electronic database of NHS patient demographic details such as name, address, date of birth, NHS Number and registered GP.

Mortality Data from the Office For National Statistics (ONS) - Information including the date, place and cause of death from the Office for National Statistics (ONS) 

HES linked to Mortality Data from the ONS - Linking HES data to mortality data from the Office for National Statistics permits the analysis of deaths in and outside hospital for all patients with a record in HES. It is also a rich source of data for analysis on a wide range of subjects including outcomes of hospital care, such as postoperative mortality.

Cancer Data from the Office For National Statistics (ONS) - Information about cancer registrations including site, type and histology from the Office for National Statistics (ONS).

Secondary Uses Service Payment by Result (SUS PbR) - National secondary care payment information from the Secondary Uses Service.

Adult Psychiatric Morbidity Survey - Provides data on the prevalence of both treated and untreated psychiatric disorder in the English adult population (aged 16 and over).

Health Survey for England - Annual survey looking at changes in the health and lifestyles of people across England.

DARS services

Local Authority HES Extract Service - Provides local authorities with direct access NHS Digital to inpatient, outpatient and A and E data, updated on a monthly basis, for the whole of England for the last ten years.

Tabulations - Statistical tables of data, tailored to meet your requirements, for HES, Mental Health and the HES routine linkage to DID.

Standard extracts - Standard extracts provide cumulative data for the financial year to date from HES, SUS PbR, DID, Mental Health and any of our routinely linked data sets, delivered monthly on an annual subscription. We will provide you with provisional year-to-date, pseudonymised data. Identifiable data may be provided where an appropriate legal basis is in place.

Bespoke extracts - We can provide tailored record-level extracts from HES, PROMS, SUS PbR, DID, ONS mortality data, and any of our routinely linked data sets. These can be provided on a one-off or regular basis as required. We will provide you with an extract of pseudonymised data that meets your specifications. Identifiable data may be provided where an appropriate legal basis is in place.
Bespoke data linkage - We can link data sets to your specifications, linking two or more sets of data that we hold, linking customer data to data that we hold, or linking two or more sets of customer data. Subject to the relevant approvals, this product is available with HES, PROMS, DID, ONS mortality data, and any of our routinely linked data sets at a frequency of your choice.

Patient status and tracking - We can provide the demographic status of a specific group of patients or track them over a period of time, and provide regular updates using PDS, ONS cancer data and ONS mortality data. We can match your chosen list of individuals to provide:

  • validation of demographic data to improve linkage outcomes and/or ensure it is accurate prior to patients being contacted. 
  • a snapshot of current demographic status and mortality including cause of death where appropriate
  • periodic long-term updates on demographic status, morbidity and mortality of a patient cohort

HES Data Interrogation System (HDIS) - Allows registered users to securely access HES and provides registered users with a wide range of analytical functions, including the ability to access, manipulate, interrogate and then report on various full-year datasets including Admitted Patient Care, Outpatients and Accident and Emergency. HDIS is provided through a secure portal and allows analysis to be performed on NHS Digital servers without any local network load.