Official Statistics

Data quality statement

Published 31 October 2024

Applies to England and Wales

• Publication for Northern Ireland
• Publication for Scotland

1. Introduction

Deaths of offenders supervised in the community statistics are published in compliance with the Ministry of Justice (MoJ) quality strategy for statistics, which states that information should be provided as to how the bulletin meets user needs. 

The MoJ aims to provide a high quality and transparent statistical service covering the whole of the justice system to promote understanding and trust. This statement sets out our policies for producing quality statistical outputs and the information we will provide to maintain our users’ understanding and trust.

Core objectives

We aim to deliver a service in line with our 4 core objectives: 

• provision of data which are accessible, consistent and fully documented 

• production of statistics which clearly communicate the story and meet users’ needs 

• provision of analysis which is timely and based on robust methodology 

• building capacity, capability and engagement 

Trust in statistics is important as statistics are fundamental to good government, to the delivery of public services and to decision making in all sectors of society. Statistics provide the parliament and the public with a window on society and the economy, and on the work and performance of government. 

Assessing the quality of statistics is not a one-off exercise. It must be done on a continuous basis. This document explains by what measures we will assess the quality of our statistics, what users can expect us to do, and the information we will provide to users to aid them in making their own assessment of the quality of the statistics we produce. 

As required by the Code of Practice for Statistics and in line with the UK Statistics Authority strategy: Statistics for the public good, we will measure and report on our quality using a framework based around European Statistical Systems (ESS) Dimensions of Quality.

2. Principle 1: Relevance

Relevance is the degree to which the statistics meet the current and potential needs of users. 

The published deaths of offenders supervised in the community statistics help users to understand trends in the number of deaths of offenders in England and Wales that occurred while they were under probation supervision.^{[footnote 1]} It also includes separate figures in relation to apparent cause of death. 

These statistics strive to be relevant across a range of users and the probation statistics team routinely seeks out feedback from both internal and external users to enhance what is published. When a change is requested, we work with analytical colleagues and data providers to explore what is possible and whether the data available is fit for this purpose before any change is made. 

Potential users can also express demand for figures through direct requests under the Freedom of Information Act, Parliamentary Questions, public discourse and our own engagement with users.

3. Principle 2: Accuracy and Reliability

Accuracy

Accuracy is the closeness between an estimated result and the (unknown) true value. 

Deaths of offenders supervised in the community are based on administrative data systems which have been established to facilitate the operational passage of offenders through the Criminal Justice System (CJS). Data up to and including March 2019 have been drawn from manual returns collected annually from each National Probation Service (NPS) division and each Community Rehabilitation Company (CRC), and each probation trust prior to the financial year ending 2015. 

Figures from April 2019 onwards have been drawn from the national Delius (nDelius) data system. Implementation of this new method was not fully successful, with the result that the information required is not always being added to the electronic records. As a result, over recent years, NPS divisions, CRCs, and, more recently, the new regional Probation Service areas have been contacted and asked to provide the information, by entering it retrospectively wherever possible, or by providing a manual return. 

Information from the electronic records and manual returns has then been brought together by staff at HM Prison and Probation Service (HMPPS) HQ, who work closely with the owners of this data system to understand how their processes work, how data is collected and how data is validated upon entry. 

We continually seek to better understand how the data is used operationally (e.g. within HMPPS) and how this may affect the statistics produced. 

As data is extracted and analysed to produce the published statistics, guidance from The Aqua Book is used to ensure thorough quality assurance procedures are adhered to during the statistics annual production process. 

Despite carrying out validation on entry, prior to submission and within the statistical processes following extraction, the data are subject to some inaccuracies inherent in any large-scale data recording system (e.g. mistyped data entries). However, the validation procedures which are implemented are felt to be proportionate in reliably minimising the impact that any errors may have on the published estimates. 

Quality assurance checks include: 

• on receipt of the data, a further series of checks are carried out, including simple sum checks, trend analysis to flag up areas of considerable change and assessing data consistency (e.g. where applicable, monitoring volumes of ‘Unknown’ or ‘Other’ groupings) 

• changes in system (including updates) and procedures can lead to reporting discrepancies as time may be needed to adjust to new ways of working. When new practices are implemented, work is conducted alongside these to ensure that the data being received is consistent and of acceptable quality before it is published 

• code used to extract and analyse the data has been rigorously quality assured 

• we verify our data with timeseries available from past data which has been extracted, and quality assurance checks are carried out within the team as the bulletin is developed 

• once all publication products are complete, an analyst conducts a full set of quality assurance checks as set out in an established ‘Quality Assurance log’, raising issues to the team 

• any subsequent corrections required prior to publication are actioned and, if required, any amendments following publication are made – fully adhering to the department’s revisions policy 

Reliability 

Reliability is the closeness of early estimates to subsequent estimated values. 

This publication and the data within it are published annually. 

In accordance with the Code of Practice for Office Statistics, the MoJ is required to publish transparent guidance on its policy for revisions. A copy of this statement can be found at Ministry of Justice statistics policy and procedures. Information on the way in which scheduled and unscheduled revisions are treated in the MoJ Deaths of offenders under supervision in the community statistics publications can also be found in the supporting guidance documentation.

4. Principle 3; Timeliness and Punctuality

Timeliness 

Timeliness refers to the time gap between the publication date and the reference period for the statistics. 

Deaths of offenders under supervision in the community statistics are based on the apparent cause of death at the time deaths were reported to HMPPS. At the time of reporting a death, probation staff may not have sufficient information regarding the circumstances of the death to assign an apparent cause, and the results of any investigations or inquests following the death do not always reach the probation providers. Therefore, while the apparent cause of death in this bulletin reflects the classification made at the time of reporting, due to time lags, it may not reflect the official cause of death as determined by the Coroner. 

Punctuality 

Punctuality is the time lag between the actual and planned dates of publication for statistics. 

Deaths of offenders under supervision in the community statistics are usually published annually at 9:30am on a date which has been pre-announced 12-months in advance, in line with the Code of Practice. 

Any change to the pre-announced release date(s) would follow the approval of the Chief Statistician for the MoJ and we would explain clearly the reasons for the changes to users at the earliest opportunity.

5. Principle 4: Accessibility and Clarity

Accessibility

Accessibility is the ease with which users can access the statistics and data. 

Annual releases providing deaths of offenders under supervision results are available on the gov.uk website; dates of future releases can be found on the Official Statistics calendar. 

These statistics seek to address a range of users’ needs and are published alongside a technical guide document to aid users’ understanding. 

Both the guide and each release include contact details for the lead statistician or the relevant mailbox within Prisons, Probation and Reoffending Data and Statistics for users to address any concerns. These inboxes are routinely monitored, and any queries are actioned as quickly as possible. 

Published data tables are available in ODS format as standard. 

This publication is compliant with the public sector’s legal obligations to meet accessibility standards.

Clarity

Clarity refers to the quality and sufficiency of the commentary, illustrations, accompanying advice and technical details. 

The commentary is written by professional statisticians and aims to be impartial, helping users put the figures into meaningful context. The bulletin is produced independently, and figures are subject to strict pre-release access for essential individuals only – no other access to statistics in their final form are made available prior to publication. 

All technical terms, acronyms and definitions are explained in the bulletin itself (where appropriate), supporting footnotes in the published data tables and in the supporting guidance documentation. 

The published data tables and tool are supported by definitional and practical guidance to support users in making accurate and reliable use of the tool functionality.

6. Principle 5: Comparability and Coherence

Comparability

Comparability is the degree to which data can be compared over time, by region or another domain. 

The administrative systems that underpin the deaths of offenders under supervision in the community statistics are in operation within the Criminal Justice System in England and Wales. 

A time series of data is presented in the publication. Any changes in source data are flagged and caveated in the accompanying technical guide as well as, where practicable, in the associated tables, charts and text; this includes notes of any variation in source and key events (e.g. policy changes) that may have affected a period. In addition, the publication makes clear when users of the statistics need to exercise caution when comparing figures

Coherence

Coherence is the degree to which the statistical processes that generate 2 or more outputs use the same concepts and harmonised methods. 

As highlighted earlier, data up to and including March 2019 have been drawn from manual returns collected annually, whilst those from April 2019 onwards have been drawn from the national Delius (nDelius) electronic data system (with further manual retrospective data recording). In addition, a Reproducible Analytical Pipeline (RAP) was introduced in the production of the statistical outputs of the April 2021 to March 2022 publication and has been used in subsequent years. All this combined means that the way in which the statistical outputs are generated in recent publications will be different to those included in previous releases. 

Users are also advised to use Official Statistics for most purposes, only using any published management information to understand the very latest high-level position.

1. Either serving a court order sentence in the community (including community orders and suspended sentence orders) or on post-release supervision after completing a custodial sentence. ↩