NHS Digital Data Release Register - reformatted

Department For Transport projects

63 data files in total were disseminated unsafely (information about files used safely is missing for TRE/"system access" projects).

HES and STATS19 One-to-one linkage project — DARS-NIC-381383-Z9F2P

Type of data: information not disclosed for TRE projects

Opt outs honoured: N, Anonymised - ICO Code Compliant, No, Yes

Legal basis: Health and Social Care Act 2012 – s261(1) and s261(2)(b)(ii), Health and Social Care Act 2012 – s261(1) and s261(2)(b)(ii), Health and Social Care Act 2012 – s261(2)(b)(ii), Health and Social Care Act 2012 - s261 - 'Other dissemination of information'

Purposes: No (Ministerial Department)

Sensitive: Non Sensitive, and Non-Sensitive

When:DSA runs 2017-12-01 — 2020-11-30 2018.06 — 2021.07.

Access method: One-Off

Data-controller type: DEPARTMENT FOR TRANSPORT

Sublicensing allowed: No


  1. Hospital Episode Statistics Accident and Emergency
  2. Hospital Episode Statistics Admitted Patient Care
  3. Hospital Episode Statistics Accident and Emergency (HES A and E)
  4. Hospital Episode Statistics Admitted Patient Care (HES APC)


The Department for Transport (DfT) has been collecting and publishing statistics on road accidents and casualties since 1927. The majority of the data used comes from police reports of the accidents. These outputs are National Statistics, and they are critical bits of evidence which are used to formulate road safety policies at both a national and local level.

The police reported data are also extensively used by police forces, researchers and commercial organisations to make the roads safer.

The police recorded data contains considerable uncertainty in the classification of injuries as being ‘slight’ or ‘serious’. The HES linkage project started during the mid- to late- 2000s to define injuries using standardised clinical data, rather than guesswork at the side of the road. The first round of matching linked police data to HES data for each year between 1999 and 2010. This linkage work was carried out by NHS Digital and its predecessor organisations resulting in a report in 2012 highlighting the differences in reported and HES outcomes. This request is for the same data from 2011 to 2016.

The objectives for the processing are:
1. To estimate the number of people who have been injured in road traffic accidents and who were treated at hospital.
2. To understand the types of injuries sustained by people injured in road traffic accidents.
3. To match the hospital records of people injured in road traffic accidents with the police record of the accident / casualty. The matching is carried out by NHS Digital and pseudonymised data returned to Department for Transport (DfT)
4. To estimate the number of people who have been seriously injured in road traffic accidents, defined as having a Maximum Abbreviated Injury Score of 3 or higher (MAIS3+)
(3 Serious, 4 Severe, 5 Critical, 6 Unsurvivable )

All statistics released by DfT will be aggregated and non-identifiable. Outputs will contain only aggregate level data with small numbers suppressed in line with HES analysis guide.

Yielded Benefits:

None, we are currently working on the data matching exercise.

Expected Benefits:

DfT currently produces statistics on the number of ‘seriously injured’ casualties in reported road traffic accidents. These figures are based on the judgement of police officers when they attend the scene of an accident. It can be very hard for officers to judge whether a casualty is slightly or seriously injured as they have neither clinical training nor access to diagnostic tools. The current measure also varies between countries, so it is impossible for comparisons to be drawn across Europe, making it harder for countries to learn from one another.

The use of hospital data will achieve three things:
1. The identification of casualties who are truly seriously injured, and in particular, the separation of people with less serious injuries from casualties with live-changing injuries.
2. Identification of all seriously injured casualties in road traffic accidents, including those which are not reported to the police. This will help deal with the underestimation problem with the road traffic accident data (there is no obligation to report accidents to the police, though anyone who is seriously injured will attend hospital and be recorded in HES data).

Each of these factors will allow DfT to produce more accurate statistics on casualties. This, in turn, will help road safety organisations identify patterns of interest and put in place interventions to reduce accidents.

HES linked data from previous years have been used to improve understanding of the types of collisions that result in the most serious injuries, as well as what type of injuries come about for specific road users in certain conditions. Local authorities have made use of this knowledge to better target interventions on the highways, and researchers have used the information to advise manufacturers of how vehicular safety can be improved.

Further details and examples:
Road safety-related benefits of using the HES data.

Road safety is a public health problem. Road collisions cost the country an estimated £35bn a year . With over 700 thousand people estimated to being injured on the roads in Britain a year , 20 thousand of whom being ‘seriously’ injured (by the definition of the police) , and almost 5 thousand having potential ‘life-changing’ injuries , there is a clear public health need for the problem to be addressed both in terms and national strategic priorities and through local operational approaches.

DfT has a role in setting the strategic direction of road safety in Great Britain and is the lead agency in producing the evidence-based used by policy-makers, operational delivery bodies, research bodies and vehicle manufacturers. "Working together to build a safer road system: British road safety statement " (,https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/487704/british_road_safety_statement_print.pdf) published in December 2015, outlines the government’s approach to improving road safety. The document specifically identifies the value of HES data in the road safety context and the government, as a whole, has committed to maximising the use of HES data to improve the evidence used by practitioners.

Improving the health of Londoners: transport action plan , (http://content.tfl.gov.uk/improving-the-health-of-londoners-transport-action-plan.pdf ) published by Transport for London in 2014, is an example of how road safety is integrated in wider the public health context at a local level.

The value of HES data lie in a number of areas:

1. HES data is the only indicator of ‘life-changing’ injuries- The serious severity in police-reported casualty data covers a wide range of injuries, including relatively minor injuries (e.g. ones that casualties will recover from quickly, or injuries for which the casualty is admitted to hospital simply as a precaution). Clinical data from HES allows DfT to understand how many people (and under what conditions and types of road users) suffer from the most serious life-changing injuries. This will help DfT formulate policies to better target / protect at risk road users. There is a public benefit in being able to target different types of interventions at different outcomes. For instance, the type of accident that are more likely to leave a casualty paralysed, or with long-term disabilities required different interventions from those that result in minor fractures. Police-reported data is not and cannot be sophisticated and reliable enough to make this distinction. Information drawn from HES, though, does achieve this.

2. Valuation of prevention of accidents- Most road safety interventions undergo cost-benefit analysis to value the benefits from accidents avoided or reduced in severity. The current valuation models are based around police-reported severities. This can result in a significant variation in the cost of accidents – for instance, a less ‘serious’ injury will have a much lower long-term cost in terms of medical care and national productivity than a more severe ‘serious’ injury. The simplistic police-reported approach makes it impossible to distinguish between these higher and lower costs. HES-derived clinical data should give a more reliable ways of modelling costs for a greater range of injuries.

3. Types of injuries suffered. -The type of injury (e.g. lower limb crushing, head injuries, etc) casualties suffer in specific types of accidents influence what mitigation and development needs to be carried out.

None of this information is available in police-records – and if DfT tried to collect it, it would probably be unreliable and misleading. HES data are the only way in which DfT can understand what types of injuries different casualties suffer.

For instance, if vehicle manufacturers and DfT (from a vehicle standards point of view) understand the types and severities of injuries that cyclists and pedestrians suffer in collisions with HGVs, DfT can better target standards and vehicle development to areas that will address these specific injuries.

Without the clinical injury information it is much harder to prioritise research and development in areas that will deliver the highest benefits that will improve the health of road users and reduce the burden on the health system.

The outputs of this work would partly be of direct benefit to DfT (e.g. by influencing road safety policy, vehicle and road design standards), but much of it will be reused by external bodies such as vehicle manufacturers and researchers which all cumulatively benefits the road users.

4. Reliability of police-reported data. - DfT has known for some time that police-reported serious injuries are under-reported. However, DfT now have concerns that underreporting is worsening as the police attend fewer accidents and it is harder for members of the public to visit a police station to report an accident. This in itself is a significant public health problem: if underreporting is increasing than the dangers and risks on the road appear to be reducing. Without taking a potential increase in underreporting of accidents into account national and local governments could make a mistake in thinking that the problems from road collisions are decreasing and going away.

Statistics derived HES provides important evidence in understanding both the scale and the potential changes in scale of underreporting. Seriously injured casualties will attend A&E and be admitted as an in-patient even if an accident is not reported to the police. It is therefore a critical source of information for the wider public health context in both validating and complementing the police-reported data.

5. Benchmarking national performance and learning lessons from elsewhere. Road safety has long been a topic for considerable international cooperation and learning. Although Britain is regarded as one of the leading countries in some aspects of road safety, there are a number of areas which we have worse performance than elsewhere (see, for instance, the PACTS / TRL report Understanding the strengths and weaknesses of Britain’s road safety performance ).

Historically international benchmarking has only been possible using information on fatalities. This is because police-reported severity definitions are both unreliable and vary across the world. One of the work packages of the SafetyCube project specifically address standardisation of clinically defined serious injuries. Although not yet published, the standard that the project has adopted is based on the Abbreviated Injury Scale (AIS – as created by the AAAM ) and identifies all casualties with an injury scoring 3 or more on the scale (referred to as MAIS3+) as being ‘seriously’ injured. This definition has also been adopted by the European Commission and is, therefore, regarded as the de facto standard throughout Europe.

Any country (including GB/UK) wishing to produce comparable statistics using this standard needs to use clinical data containing ICD codes akin to HES data.

Once statistics are available from a number of countries it will be much easier for public health and road safety leads in Britain to identify areas of good practice from other countries and adopt them here for the health benefit of all road users and to reduce the burden on the NHS from road traffic accidents.


The output statistics will be released as part of the Reported Road Casualties Great Britain publication in September each year.

Outputs will contain only aggregate level data with small numbers suppressed in line with HES analysis guide.

All the statistical reports and tables are available to everyone free of charge.
The most recent report is available at https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/9279/rrcgb2011-06.pdf.
Previous Annual Reports are also available on The National Archives website.


All individuals who have access to the record level data supplied by NHS Digital have it on a need to know basis and are substantive employees of the Department of Transport. They will use the data only for the purposes described in this document

NHS Digital will match STATS19 data (police recorded road accident data) to Hospital Episode Statistics data. DfT will supply for linkage postcode, age, sex, date of accident. NHS Digital will also supply non-matched episodes with matching road accident codes. This means that DfT will receive hospital data that can be compared with police reporting and all accidents not reported to police. All data will be returned to DfT in a pseudonymised format.

DfT will hold the pseudonymised data in a secure database with restricted access to specific individuals. The pseudonymised data will be stored separately from the STATS 19 data. Most of the analysis will on the HES data in isolation. However, some analysis will take place linking the HES data to the non-identifiable STATS 19 data consisting of data such as road type, speed limit, conditions etc. The HES data will never be linked back to the postcode and age data held within the STATS19 database. Data storage and access will only be in DfT’s secure network.

DfT will convert the ICD-10 codes (for causation of the injury, type of injury and severity of injury) into AIS scores. DfT will use the information to produce analysis of the number of people with a MAIS score of 3 or greater, plus analysis of the types of injuries different road user groups suffer from.

Annual police recorded road traffic accident casualties matched with key HES variables (e.g. ICD-10 codes). To be completed for 2011, 2012, 2013, 2014, 2015 and 2016 data, and repeated annually.

The output statistics will be released as part of the Reported Road Casualties Great Britain publication in September each year.

Outputs will contain only aggregate level data with small numbers suppressed in line with HES analysis guide.

All the statistical reports and tables are available to everyone free of charge.
The most recent report is available at https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/9279/rrcgb2011-06.pdf.
Previous Annual Reports are also available on The National Archives website.

This application also requests the retention of HES data previously supplied for the following reason. A lookup file is being developed to determine the Abbreviated Injury Score (AIS) for ICD-10 codes relating to consequences of external causes which enables MAIS3+ estimates to be generated. The lookup file is still under development and will be updated in the future. Losing the data back to 1999 will mean that the Department cannot update its estimates of MAIS3+ casualties back to 1999 when the lookup file is updated. This will represent a loss to the Department’s road safety evidence base. Further information can be found in the report published at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/556648/rrcgb2015-03.pdf

All the statistics that will be released by DfT will be aggregated by user group, geography, etc. No identifiable data will be released. Outputs will contain only aggregate level data with small numbers suppressed in line with HES analysis guide.

All organisations party to this agreement must comply with the Data Sharing Framework Contract requirements, including those regarding the use (and purposes of that use) by “Personnel” (as defined within the Data Sharing Framework Contract ie: employees, agents and contractors of the Data Recipient who may have access to that data).