These data source overviews are intended to give you a high-level view of new data sources included in the Administrative Data Research Outputs. The emphasis is on the statistical quality of the source and how this affects the scope of its use in producing research outputs, rather than the operational quality of the administrative data source. It is anticipated that this overview will be updated in future years as the understanding and use of the data progresses.

2017 publications

We received an additional extract of the Personal Demographic Service (PDS) for 2014 to 2016 (previously the data covered 2011 to 2014). These new data were used in the production of Statistical Population Dataset (SPD) V2.0 2016 estimates. All our SPDs for previous years use the PDS movers' extract 001.

Work is ongoing to determine the feasibility of using the PDS data in place of the Patient Register (PR), as the National Health Service (NHS) will use the PDS as the primary source of patient demographic information in England.

The Digital Economy Act 2017 was passed into law in April 2017. The Act gives Office for National Statistics (ONS) a right of access to information held by government departments, other public bodies, charities and large and medium-sized businesses, for statistics and research purposes.

2016 publications

Source information

Source information Dataset: Personal Demographics Service (PDS) data -- movers' extract 001 Supplier: NHS Digital (formerly Health and Social Care Information Centre (HSCIC)) Version: Movers' extract 001 Geography: England and Wales Time period: 2011 to 2014


The PDS system is the master demographics database for the NHS in England, Wales and the Isle of Man. It is the primary source of information on a patient's NHS number, name, address and date of birth. It does not hold any clinical information. The master database contains approximately 74 million patient records. Records are created for newborns or when a patient makes contact with an NHS service, primarily by registering with a General Practitioner (GP) practice, but also through accessing A&E or attending hospital. The PDS is used by NHS organisations and enables a patient to be readily identified by a healthcare professional to quickly and accurately obtain their correct medical details.

We are supplied PDS data as an extract from the PDS system. We were provided with a movers' extract of the PDS, showing all changes in postcode that took place within a set period of time (that is, "June 2011" refers to patient moves that resulted in address changes between 1 July 2010 and 30 June 2011). Each annual movers' extract from 2011 to 2014 contained approximately 8 million patients, all of whom will have moved one or more times.

Data sharing arrangements

In 2014, we received four years' worth of PDS data via a portal from HSCIC (now operating as NHS Digital). The legal gateway for sharing these data from NHS Digital to Office for National Statistics (ONS) came via the Statistics and Registration Service Act 2007 (SRSA).

These data were provided for the purposes of assisting the production of population statistics as stated under "Sections 43 and 44: Information relating to NHS registration".

The data received are held in a secure environment, which can be accessed only by our analysts who meet a set of security standards.

The Digital Economy Act 2017 amended the Statistics and Registration Service Act 2007 to provide us with greater and easier access to a range of data sources held within the public and private sectors, improving the quality and usability of official statistics and National Statistics. The amendments have created a legal gateway for data owners to provide access to data they hold, for us to fulfil our statistical functions. The amended legislation also established the statutory conditions to enable us to work in partnership with data holders to identify and address the main security, privacy and resource implications of our access to data.

In addition to setting out strict limitations on the use of data provided in this way, the legislation also reinforced sanctions for the misuse of data and the main protections set out in the Data Protection Act 1998. These safeguards collectively ensure that data holders and the public can be confident that data will be used in a proportionate and accountable fashion to support the production of statistics and statistical research for the public good.


The main variables from the PDS data include patient's age, sex, NHS number (which provides the unique identifier with which to link to other heath data sources including the Patient Register), effective date, postcode of patient's previous address (before the move on PDS) and postcode of patient's current address (after the move on PDS). These postcodes are used to determine the former and current local authorities used to place people geographically in the Research Outputs.


The 2011 to 2014 data extracts included anyone who interacted with a PDS-based system in England and Wales during these years and logged a different postcode at least once during any year-long period. Therefore, the data cover "movers" as well as new NHS registrations (those arriving, either through migration to England and Wales or newborns). These interactions with the PDS system represent a sign of activity1 and evidence that someone is living at a certain address.

Previous residents of Scotland and Northern Ireland are not distinguishable. Although they may appear on the PDS as movers, their previous postcodes and addresses are not included.

Only those patients whose usual residence was established as being in England and Wales were included in the population counts for the Research Outputs.

The PDS system will include everyone who is on the Patient Register but may include extra records that would be excluded from the population counts for the Research Outputs, for example:

  • patients who have died but whose records have not yet been removed

  • non-residents (for example, short-term visitors) who have accessed a PDS-supported system (such as A&E) but who may not go on to register with a GP


  1. "Activity" can be defined as an individual interacting with an administrative system, for example, for National Insurance or tax purposes, when claiming a benefit, attending hospital or updating information on government systems in some other way. Only demographic information (such as name, date of birth and address) and dates of interaction are needed from such data sources to improve the coverage of our population estimates.

Statistical use in Administrative Data Census Project

PDS data can be used as evidence of "activity" to correctly assign people to a location based on their postcode change. This relies on people updating their address truthfully and in a timely manner with their GP or some of the other NHS services capable of updating the PDS. Discrepancies may arise when a patient provides different NHS services with different addresses.

PDS data were used in the 2016 Research Outputs. They were used:

  • as an indication of a person's "activity" to confirm their address where there is discrepancy between the addresses available on other data sources used; this helps to resolve the issue of people being partially assigned across two locations

  • to help build up a history of address moves to help build evidence to determine which address individuals should be assigned to

More detail on how PDS data have been used is available in section 5 of the Methodology report.


In future, the use of PDS data in the Research Outputs may extend to removing records if there is a lack of evidence that they are still part of the usually resident1 population.

The PDS address may be used in future where it is expected to be more reliable than the address held on other sources. We are pursuing more recent years of PDS data, which will complete a longer time series from 2011 to 2016. This will feed in more timely evidence of addresses for future admin data population counts.


  1. Usually resident population – we are currently adopting the UN definition of "usually resident" – that is, the place at which a person has lived continuously for at least 12 months, not including temporary absences for holidays or work assignments, or intends to live for at least 12 months (United Nations, 2008).