# Proven Reoffending Statistics: Definitions And Measurement

 Published October 2016 

## Contents

Contents 
................................................................................................ 
2 
Introduction .......................................................................................... 
3 
Measurement ........................................................................................ 
4 
Definitions for the measurement of proven reoffending ...................... 
5 
Definitions for the measurement of interim proven reoffending for Community Rehabilitation Companies and the National Probation Service
 
............................................................................................................ 
9 
Data quality ......................................................................................... 
14 
Police National Computer data ......................................................... 
14 
Prison data 
........................................................................................ 
15 
Probation data .................................................................................. 
17 
Young offenders in secure accommodation 
...................................... 
17 
Data processing and analysis ........................................................... 
18 
Matching offender records ................................................................ 
18 
Counting rules 
................................................................................... 
19 
The extraction of the criminal histories 
.............................................. 
19 
Level of subjectivity 
........................................................................... 
20 
Maturity and stability of the data system ........................................... 
20 
Expertise of those who operate the system ...................................... 
20 
Data on historical trends ................................................................... 
21 
Appendix A: Glossary of terms 
......................................................... 
23 
Explanatory notes .............................................................................. 
30 
Contact details 
.................................................................................... 
31 

## Introduction

This document supplements the quarterly Proven Reoffending Statistics bulletin by providing a comprehensive guide to the statistics. This document focuses on concepts and definitions published in Ministry of Justice statistics and the counting procedures used to produce them. It also provides explanations of data sources and quality. This bulletin is published alongside two inter-related bulletins: 
Offender Management Statistics Quarterly: provides key statistics relating to offenders who are in prison or under Probation Service supervision. 

Safety in Custody Statistics Quarterly: provides statistics on death, selfharm and assault incidents whilst in prison custody. The publication in its current form is a result of a statistical consultation on improvements to the transparency and accessibility of our information launched in 2010 and a response to the consultation was published in March 2011. One aspect of the consultation was the measurement of proven reoffending. Responses supported the proposals to move to a single framework for measuring reoffending where adult and youth data can be provided at national and local levels on a consistent basis. From 30 July 2015 to 30 October 2015, a more recent consultation on changes to the proven reoffending statistical publication was launched. The key change that was proposed was to align the existing reoffending measure with those measures necessary for assessing progress against the rehabilitation reforms. 

This consultation outcome summarises the responses received to that consultation. Having considered the responses to the consultation, details of the post consultation position are: 

 
Proven reoffending measures will be published using the proposed 3 month cohorts; 
 
The new publication will contain a chapter on Community Rehabilitation Companies (CRC) Payment by Results and National Probation Service (NPS) division proven reoffending performance measure; 
 
For assessing the likelihood of reoffending OGRS4/G will be used for adult cohorts and for juvenile cohorts the Youth Offender Group Reconviction Scale (YOGRS) will be used; 
 
From October 2016 we will provide interim Payment by Results. 
 The existing adult and juvenile reoffending statistics will continue in their current form until the reoffending outcomes for the first Payment by Results cohort become available in October 2017. 

## Measurement

The underlying principle of measuring reoffending (or recidivism, which is the most commonly used term internationally) is that someone who has received some form of criminal justice sanction (such as a conviction or a caution) goes on to commit another offence within a set time period. Measuring true reoffending is difficult. Official records are taken from either the police or courts, but they will underestimate the true level of reoffending because only a proportion of crime is detected and sanctioned and not all crimes and sanctions are recorded on one central system. Other methods of measuring reoffending, such as self report studies, are likely to also underestimate the rate. Following the Ministry of Justice Consultation on Improvements to Ministry of Justice Statistics, a **proven reoffence** is defined as any offence committed in a one year follow-up period that resulted in a court conviction, caution, reprimand or warning in the one year follow-up or a further six month waiting period (to allow time for cases to progress through the courts). The data source is the extract of the Police National Computer (PNC) held by the Ministry of Justice. 

 

## Definitions For The Measurement Of Proven Reoffending

Cohort This is the group of offenders for whom reoffending is measured. For the Proven Reoffending Statistics Quarterly Bulletin, this is defined as all offenders in any one year who received a caution, a final warning or reprimand (for juveniles prior to April 2013), a non-custodial conviction or who were released from custody. Offenders who were released from custody or secure accommodation (juveniles only) or commenced a court order are matched to the PNC 
database. A proportion of cases are lost in this process because they cannot be matched (see the section below titled "Matching offender records" 
for further details). Additionally, offenders who appear multiple times in the cohort are only included once (see the section below titled "Multiple offender entries" for further details). The group of offenders whose offending behaviour is proven is likely to be a sub-group of all active offenders. The Offending, Crime and Justice Survey (2003)1 estimated that around one in ten people in England and Wales aged between ten and 65 had committed an offence in the previous 12 months, which translates into approximately 3.8 million people. This compares to around 632,000 offenders in the 2002 cohort used to measure proven reoffending, underlining that the offenders whose proven reoffending behaviour is presented in the Proven Reoffending Statistics Quarterly Bulletin are a small and probably unrepresentative sample of the population of all active offenders. 

Index disposal (sentence type) 
The index disposal of the offender is the type of sentence the offender received for their index offence. For the Proven Reoffending Statistics Quarterly Bulletin, this is defined as custody, court order, other disposal resulting from a conviction at court, such as a fine or discharge, caution, reprimand or final warning (young offenders). 

Index offence The index offence is the proven offence that leads to an offender being included in the cohort. An offence is only counted as an index offence if it is: 

 recordable (see below); 
 
 committed in England and Wales; 
 
 prosecuted by the police; and 
 
 not a breach offence. 

 
Start point (index date) 
This is the set point in time from when proven reoffences are measured. For the *Proven Reoffending Statistics Quarterly Bulletin*, this is defined as the date of prison release, the date of court conviction for non-custodial sentences, or the date of receipt for a caution, reprimand or final warning. 

Follow-up period This is the length of time over which proven reoffending is measured. For the *Proven Reoffending Statistics Quarterly Bulletin*, this is defined as 12 months from the start point. 

 
Waiting period This is the additional time beyond the follow-up period to allow for offences which are committed towards the end of the follow-up period to be proven by a court, resulting in a conviction, caution, reprimand or final warning. For the *Proven Reoffending Statistics Quarterly Bulletin*, this is six months. Figure 1 below illustrates why different offences for an example offender are included or excluded in the proven reoffending measure. 

 
 
Events A to D all occur in the one year follow-up period, but events E and F are outside this period, so would not be counted. Events A to C are all counted because they were all proven within the one year follow-up period or the further six month waiting period. Event F, even though the offence took place in the 6 month waiting period, it would not be counted, as the event took place outside of the one year follow up period and conviction did not occur within either the one year follow-up period, or the further six month waiting period. The offender has, therefore, committed six proven offences during the one year follow-up period (two for event A, one for event B, three for event C). 

Proven reoffence Offences are counted as proven reoffences if they meet all of the following criteria: 
 

 They are recordable. Not all offences are on the PNC and more 
recordable offences are entered than non-recordable offences. Analysis comparing offences proven at court with offences recorded on the PNC suggests the most cost common offences that are not 
recorded relates to motor vehicles, e.g. using a motor vehicle whilst uninsured against third party risks, speeding offences, keeping a vehicle on the highway without a driving licence or television licence evasion. 
 
 They were committed in England or Wales. 
 
 They are offences that were prosecuted by the police. PNC data are 
collected and input by the police and offences prosecuted by the police are likely to be recorded more comprehensively on the PNC than offences that are prosecuted by other organisations. For example, benefit fraud is prosecuted by the Department for Work and Pensions. Therefore, benefit fraud offences may be poorly represented on the PNC. 
 
 Offences are only counted if they are proven through caution, 
reprimands or final warnings (for juveniles) and court convictions. Offences that are not proven, or which meet with other responses from the Criminal Justice System, are not counted. The Offending, Crime and Justice Survey (2003) estimated that 6% of all offences resulted in any contact with the Criminal Justice System. 
 
 The offence is not a breach offence, i.e. breach of a court order, 
since we are only interested in new offences. 

## Measures Of Proven Reoffending Proven Reoffending Data Are Presented In The Following Ways:

 The number of offenders. 
 
 The proportion of offenders who are proven reoffenders. 
 
 The average number of proven reoffences among **reoffenders**. 
 The proportion of proven offenders who committed a proven 
indictable reoffence. 


Multiple offender entries Each offender is tracked over a fixed period of time and any proven offence committed in this period is counted as a proven reoffence. A multiple offender entry refers to an offender who, after entering the cohort in a given year, commits a reoffence and is either cautioned, discharged from prison or gets a non-custodial conviction in the same cohort year. This reoffence could also be included as a second entry for this offender into the cohort. 

 

Re-offence 2 

Re-offence 2 

Re-offence 3 

Re-offence 3 

 
Offender Cautioned
Re-offence 1 
Offender starts a community sentence 
Offender Cautioned Offender Cautioned
Re-offence 1 
Offender starts a community sentence 
Offender sentenced to 3mnths in prison 
then released 
Offender sentenced to 3mnths in prison 
then released 
Offender sentenced to 3mnths in prison 
then released 

 
1 year cohort period 1 year cohort period To date, publications have avoided the double counting of these multiple offender entries (MOE) by only counting an individual once based on their first proven offence in the relevant time period. In the illustration above, the caution would be counted as the index disposal and the further two proven offences would be counted as reoffences. This avoids double counting of proven reoffences. In this publication the main tables (tables A1 to A6 and B1 to B4) in the report have been produced on the basis of the 'first proven offence in the relevant time period', which led to an offender being included. This provides a picture of proven reoffending which is consistent with previous publications and tracks an offender, irrespective of the disposal they receive, to when they commit a proven reoffence. 

The measure of proven reoffending now covers all offenders in any one year instead of the first quarter of a calendar year as in previous proven reoffending publications. The result is many more offenders with multiple entries. In addition, including cautions to identify a proven offence means many offenders' first offence will be associated with a caution since cautions account for around a third of adult offenders in one year. Table 1 shows the number of offenders in each cohort period by their number of entries. 

2000, 2002 to 2012 cohorts2 

Multiple Offender Entries
2000
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
1
512,551
522,376
544,031
549,545
580,709
615,775
630,748
602,251
572,068
528,466
498,364
459,250
2x
75,311
77,813
81,651
78,827
80,968
86,866
90,870
87,427
83,235
78,430
74,314
66,028
3x
19,565
21,208
22,073
20,840
20,908
21,823
23,590
23,499
22,005
21,332
20,479
17,892
4x
6,195
6,689
7,074
6,833
6,720
6,768
7,605
7,882
7,319
7,396
7,115
6,289
5x
1,998
2,314
2,392
2,355
2,355
2,411
2,774
2,894
2,927
2,902
2,963
2,592
6 to 10x
1,240
1,510
1,689
1,641
1,505
1,509
1,964
2,332
2,303
2,361
2,500
2,292
Greater than 10x
164
155
129
131
119
115
114
160
202
193
190
178
Total MOEs
104,473
109,689
115,008
110,627
112,575
119,492
126,917
124,194
117,991
112,614
107,561
95,271
% of total cohort
16.9%
17.4%
17.5%
16.8%
16.2%
16.3%
16.8%
17.1%
17.1%
17.6%
17.8%
17.2%
Cohort
617,024
632,065
659,039
660,172
693,284
735,267
757,665
726,445
690,059
641,080
605,925
554,521

 The number of offenders with multiple entries has remained fairly constant over time - the proportion of the total that had multiple offender entries has remained at about 16 to 18% between 2000 and 2012. Proven reoffending by index disposal, probation trust and prison In order to measure proven reoffending on a consistent and representative basis by offender management groups, it is necessary to distinguish between the disposal (sentence) types that led to an offender being included. Doing this allows the cohort to be defined according to the relative start point of an offender's interaction with the prison (released from custody) or probation services (court order commencement). Tables C1-C3 provide reoffending data by disposal (sentence) types. These are produced on the basis of an individual's first disposal (sentence) in that category. In figure 2 above, the individual would appear once in the caution category, once in the community order category and once in the custody category. These tables will include an overall prison and probation proven reoffending rate which will be the figures we quote publicly. However, these figures should not be used when comparing proven reoffending rates across different disposals to compare effectiveness of sentences. Instead the Compendium of Reoffending Statistics and Analysis 2013 publication should be referred to as this analysis controls for offender characteristics in order to give a more reliable estimate of the relative effectiveness of different disposals. The prison/youth secure accommodation/probation trust data tool provide reoffending rates by individual prison and former probation trust, and National Probation Service Division (NPS). These are produced on the basis of an individual's first disposal from each specified prison or probation trust. If the individual offender is discharged from two different prisons in the year they will appear in both of the prison's reoffending rates. The same applies for offenders commencing court orders in more than one probation trust within the year. This is to allow prisons and probation services to track their caseload of offenders. 

Definitions for the measurement of interim proven reoffending for Community Rehabilitation Companies and the National Probation Service The Transforming Rehabilitation reforms included opening up the probation service to a diverse range of rehabilitation providers from the private, voluntary and social sectors through 21 Community Rehabilitation Companies (CRCs) and creating a new public sector National Probation Service (NPS), to manage high risk offenders. A Payment by Results (PbR) approach was adopted for the 21 CRCs to develop and implement effective ways of rehabilitating offenders and 
 
rewarding providers that devise and deliver the most effective rehabilitation programmes. Final reoffending results for the CRC PbR offender cohorts will be based on a **one year proven reoffending measure**. One year proven reoffending statistics for PbR will be published in October 2017. To address this interim gap in knowledge, the Ministry of Justice will publish interim reoffending results from October 2016. The interim reoffending results are based on a reoffending-to-date measure. This will allow CRCs' progress to be assessed at the earliest opportunity. Equivalent interim figures for the NPS divisions will also be produced. These estimates will only give an indication of progress and, therefore, care should be taken when interpreting them. Cohort This is the group of offenders for whom reoffending is measured. For the Interim Proven Reoffending Statistics for CRCs and NPS Quarterly Bulletin this is defined as all adult offenders in any one quarter (January to March, April to June, July to September, October to December) who begin a community order, a suspended sentence order or who were released from custody. For CRC proven reoffending, this group represents the eligible cohort. Offenders who were released from custody or commenced a court order are matched to the PNC database. A proportion of cases are lost in this process because they cannot be matched. The process uses automated matching routines that look at offenders' surnames, initials, dates of birth and gender, using direct name matching along with a variety of 'sounds like' algorithms. The matching algorithm also searches through PNC held information on alias names and dates of birth for offenders. Additionally, offenders who appear multiple times in the cohort are only included once (see the section below titled "Multiple offender entries" for further details). For CRC proven reoffending, **eligible** offenders that can be matched to the PNC database represent the **measurable cohort**. This is the group for whom reoffending can be measured. 

Offenders are only included in a CRC's PbR cohort the first time they commence an eligible sentence (see below for exclusions) in the three month period. The same methodology will be used for each NPS division's proven reoffending performance measure. 


- released from a custodial sentence; - who begin a community order; - who begin a suspended sentence  order; 
- Aged 18 or over
 
Start point (index date) 
This is the set point in time from when proven reoffences are measured. For the Interim Proven Reoffending Statistics for CRCs and NPS Quarterly Bulletin this is defined as the date of prison release or the date of sentence for court orders. 

Follow-up period This is the length of time over which proven reoffending is measured. For the Interim Proven Reoffending Statistics for CRCs and NPS Quarterly Bulletin instead of measuring reoffending with a defined follow-up and waiting period, this interim estimate would count any proven reoffending to date as recorded on the MoJ's PNC data extract (see diagram below). 

Some offenders in the three month cohort will have a longer follow-up period in which to reoffend. An offender enters the cohort if they are released from custody or are sentenced to a community order or a suspended sentence order in the period October to December 2015. 

 

## Proven Reoffence The Same As For The Headline Proven Re-Offending Figures Presented In The Proven Re-Offending Statistics Quarterly Bulletin. Measures Of Interim Proven Reoffending Interim Proven Reoffending Data Are Presented In The Following Ways:

 The number of eligible offenders. 
 
 The number of measurable offenders. 
 
 The proportion of measurable offenders who are proven reoffenders. 
 
 The average number of proven reoffences among **reoffenders**. 
 
 The offender group reconviction scale average score. 
 
Multiple offender entries Each individual offender is allocated to a quarterly cohort only once, based on their first eligible entry in a given quarter. For the final results, annual cohorts will be formed by combining the four quarterly cohorts of the relevant year. An individual offender can, therefore, appear up to four times within a single annual cohort (one from each quarter). Interim proven reoffending by CRCs and NPS divisions An offender can move within the three month cohort period and supervision can be transferred to another CRC provider. An offender can also be transferred from being supervised by a CRC to being supervised by an NPS division if a high risk offence is committed within the three months. If an offender is managed by more than one different CRC or NPS division within the same three month cohort period, reoffending is measured against the first CRC or NPS division the offender is allocated to. Offender Group Reconviction Scale For the final reoffending results, CRCs' performance in reducing reoffending will be assessed against the baseline year of 2011. As proven reoffending is related to the characteristics of offenders, the actual rate of proven reoffending will depend, in part, on the characteristics of offenders coming into the system. This actual rate provides users with sufficient information on what the level of reoffending is and how it is changing over time. In addition to the actual rate, the Offender Group Reconviction Scale version 4/G3 is used to control for some differences in offender characteristics across different offender groups. OGRS4/G is based on a well-established, peer-reviewed methodology for assessing and representing reoffending risk. 

OGRS4/G uses age, gender and criminal history to assess the reoffending risk of a given group of offenders by producing a score between 0 and 1. These scores can be used to compare the relative likelihood of reoffending either over time or between different groups of offenders, with a higher rate meaning a group of offenders who are more likely to reoffend. For the final reoffending results, the reoffending rate for each CRC will be adjusted by using OGRS4/G, to take account of the influence that differences in offender mix can have on binary rates. OGRS4/G adjusted rates will be used to determine final PbR outcomes. The frequency rate will not be adjusted. 

The OGRS4/G adjusted reoffending rate for a given CRC cohort will be calculated as the observed reoffending rate for that cohort plus any difference between the OGRS4/G score in that cohort and the 2011 CRC baseline cohort. This calculation standardises the mix of offenders in each cohort of a given CRC to the 2011 mix for that same CRC. It will not be possible to adjust the reoffending rate for interim results because OGRS4/G only offers a one and two year prediction of reoffending and interim results are based upon a reoffending-to-date measure. 

 

## Data Quality

The data required for measuring proven reoffending are based on a range of data sources (prison data, probation data, young offenders in secure accommodation, and criminal records from the Police National Computer) from a range of agencies (the National Offender Management Service, the Youth Justice Board, local authorities and the National Police Improvement Agency). These figures have been derived from administrative IT systems which, as with any large scale recording system, are subject to possible errors with data entry and processing. 

 
Police National Computer data Information regarding the proven reoffending behaviour of offenders has been compiled using the Ministry of Justice's extract from the Police National Computer (PNC). The process involves matching offender details from the prison and probation data to the personal details recorded on the PNC. A proportion of cases cannot be matched and the figures presented in Table 2 below and are expressed as a percentage of the offenders that are matched. Like any large scale recording system, the PNC is subject to errors with data entry and recording. The PNC is regularly updated so that further analysis at a later date will generate revised figures. The quality of the information recorded on the PNC is generally assumed to be relatively high as it is an operational system on which the police depend, but analysis can reveal errors that are typical when handling administrative datasets of this scale. The extent of error or omitted records on the PNC is difficult to estimate because it is a unique data source. As a result, there is not always an obvious source of data to provide a baseline from which to assess data quality. For some types of results, however, comparisons can be made. For example, the trend in receptions into prison in each month is very similar using the PNC and prisons data (see below for details). Although the number of receptions recorded on the PNC is consistently slightly lower because prisons data include cases on remand whereas the PNC does not. Another example is the number of cases that are given a custodial sentence, broken down by offence type, which is similar using the PNC and the Court Proceedings Database with a match rate of 97%. A number of improvements are routinely carried out: 

 Updates to the coding and classification of offences and court 
disposals, including the reduction of uncoded offences, the reduction in the use of miscellaneous offence codes and the clarification of the coding of breach offences; 
 Updates to the methods used to identify the primary offence, where 
several offences are dealt with on the same occasion, and the 
methods used to identify the primary disposal, where an offence attracts more than one court disposal; and 

 Removal of some duplication of records within the database resulting 
in improvements to the efficiency and reliability of the matching process. 
 

## Prison Data

Prison establishments record details for individual inmates on the prison IT 
system (Prison-NOMIS or LIDS). The information recorded includes details such as date of birth, gender, religion, nationality, ethnic origin, custody type, offence, reception and discharge dates and, for sentenced prisoners, sentence length. The data from individual prison establishments then feeds through to a central computer database, called the Inmate Information System (IIS). In May 2009, the National Offender Management Service (NOMS) began the roll-out of a new case management system for prisons (Prison-NOMIS). During the phased roll-out, data collection issues emerged that affected the supply of data for statistical purposes from July 2009 to February 2010. Specifically, statistical information on sentence length and offence group is not available on any of our prison datasets for this period. In order to ensure the fullest possible set of data from July 2009 to February 2010, sentence lengths were estimated for those prisoners received or discharged before the problems were resolved. At the point when the problems were resolved, a small number of prison establishments were still using the old LIDS case management system; data for prisoners received or discharged from these prisons was assumed to be unaffected. For those prisoners received or discharged from prisons operating Prison- NOMIS, efforts were made to populate their record with the correct sentence length using other data extracts. For example, many prisoners discharged in January 2010 were originally received into prison prior to July 2009, so their sentence length was taken from unaffected datasets before the problems began. Similarly, the majority of those received in early 2010 were still in prison in March 2010 when the problems were resolved, so the sentence length from the corrected prison population data was used. Where it was not possible to populate a sentence length using other datasets, prisoners were allocated a sentence length band based on the number of days they spent in custody (taking account of early release schemes where relevant). As a check on the methodology, an alternative estimation process was designed and the number of discharges in each sentence length band for the second half of 2009 was compared using the two methods. 

 
A number of estimation methods were considered and tested on the 2008 data (prior to the data problems) to see which yielded estimates closest to the actual 2008 data. This identified the following method: 

1. Calculate data for the first half of the year as a proportion of the full 
calendar year, for each year from 2001 to 2008; separately for each sentence length band or offence group (the two key breakdowns to be estimated). 2. Apply the average of these proportions to the January to June 2009 
data to estimate the 2009 annual totals; separately for each sentence length band or offence group. 3. Scale the estimated numbers in each sentence length band or 
offence group to sum to the annual total recorded in the raw data (where the totals are known to be correct). 
 
The maximum difference between the two approaches was 2.6% in the band '12 months to less than 4 years'; for all other bands the difference was less than 1%. 

Indeterminate sentence prisoners In addition to the above, data on the discharge of prisoners on indeterminate sentences, i.e. prisoners given a life sentence or an Indeterminate sentence for Public Protection (IPP), is provided from the Public Protection Unit Database (PPUD). This holds data jointly owned by the Offender Management and Public Protection Group (OMPPG) in NOMS and the Parole Board. PPUD records details of all indeterminate sentence prisoners at the point of conviction, those engaged in the Generic Parole Process and prisoners (determinate and indeterminate) who have been recalled from licence. It also covers those who have received a restricted hospital order/direction from a Crown Court, and those remand and convicted prisoners who have been transferred from prison/detention centres to psychiatric hospital under the relevant sections of mental health legislation. All decisions taken by the NOMS casework sections and the Parole Board are recorded on the system. Personal information recorded includes (but is not limited to) name, date of birth, gender, identifying numbers, ethnicity, last known address, probation area and sentencing information. OMPPG and the Parole Board run monthly and ad hoc reports to cleanse data that are not otherwise identified by data validation routines built into the system. For the interim proven reoffending statistics, prison discharge data are sourced from the nDelius case management system (for further information about nDelius, please see the section on probation data below). 

## Probation Data

Since 2005, detailed information on the supervision of offenders (at the individual offender level) had been submitted by probation trusts on a monthly basis. These monthly 'probation listings' included information on offenders starting probation supervision. Between 2002 and 2005, this information was submitted quarterly, and prior to 2002 a different data collection system was in place, which meant that information on caseload had to be calculated based on the number of people starting supervision and the number of terminations. From June 2014, the Transforming Rehabilitation programme was launched, which changed the way offenders are managed in the community. Management of offenders serving their sentence in the community has been split into two groups, one consisting of high risk offenders who are managed by the National Probation Service (NPS) and another group consisting of low to medium risk offenders who are now managed by Community Rehabilitation Companies (CRCs). 

 
The quality of the information recorded on the probation data is generally assumed to be relatively high as it is a direct extract from an operational system upon which the probation service depends for managing offenders locally. The extract consists of a small number of key fields for which completion is mandatory. Data is received centrally via the nDelius case management system and is subject to another set of data validation processes. Trends from the data are consistent with comparable time series from the Courts Proceeding Database. Any large scale recording systems are subject to possible errors with data entry and processing, but there are no known issues regarding the probation commencements data. 

Young offenders in secure accommodation Information about secure training centres (STCs) and secure children's homes (SCHs) comes from the Youth Justice Board's (YJB) eAsset database. Information about young people aged 17 and under and held in YOIs is supplied by the Prison Service and private YOIs. The YJB monthly custody report has traditionally used data from the Secure Accommodation Clearing House System (SACHS), this was the system used by the YJB to book young people into custody. To meet information management challenges of a growing department and whilst improving our processes, the YJB has migrated to the use of the new eAsset system since March 2012. 

 
As part of the work to implement the new system both SACHS and eAsset were run in parallel from 5th March to 1st July 2012. The YJB now has the ability to produce some reports from eAsset and has done work to quality assure the outputs against SACHS. While this work is ongoing and further reports are being developed we now believe the quality of data from this system is of a suitable level to publish as management information. 

 
The quality of the information recorded on the eAsset database is generally assumed to be relatively high as it is a direct extract from an operational system which is used to place young people in custody. The extract uses a number of key fields for which completion is mandatory when booking a young person into custody. 

Data processing and analysis The data underpinning the results are considered by Ministry of Justice to be broadly robust. Considerable work has been carried out ensuring data quality, and the data have been used for research publications. Scrutiny of the data source continues in order to ensure the data remains reliable. The National Audit Office (NAO) identified risk factors in its review of the reporting of PSA targets (NAO, 2005). The remainder of this section addresses these. 

Matching offender records This process involves matching data on prison discharges and court order commencements to the PNC database. The process uses automated matching routines that look at offenders' surnames, initials, and dates of birth, using direct name matching along with a variety of 'sounds like' 
algorithms. The matching algorithm also searches through PNC held information on alias names and dates of birth for offenders. However, not all offenders are matched and a thorough analysis of bias in the matching system has yet to be undertaken. Table 2 below shows that the overall matching rates between 2000 and 2012 have remained high. 

Table 2: Matching rates for the different data sources for 2000, 2002 to 2012 cohorts1 

2000
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Prison
Prison discharges
87,083
87,338
85,920
86,970
84,897
83,725
87,340
95,824
94,114
93,137
89,773
91,009
Automatically matched to the PNC
80,572
81,211
80,121
81,125
79,398
78,285
81,874
90,021
88,745
87,845
84,950
86,333
Matched to an index date
73,810
75,121
73,327
73,390
71,246
68,185
69,741
76,668
74,189
65,278
67,512
71,059
Percentage matched to the PNC
92.5%
93.0%
93.3%
93.3%
93.5%
93.5%
93.7%
93.9%
94.3%
94.3%
94.6%
94.9%
Percentage matched to the PNC and index 
84.8%
86.0%
85.3%
84.4%
83.9%
81.4%
79.9%
80.0%
78.8%
70.1%
75.2%
78.1%
offences (not breach etc.)
Court Orders
Court order starts
136,023
154,621
158,750
164,831
163,681
176,346
187,386
189,643
191,784
186,417
179,206
165,959
Automatically matched to the PNC
123,540
142,838
148,257
154,075
158,416
172,906
184,740
187,253
190,128
185,112
178,026
164,937
Matched to an index date
105,685
115,108
119,446
122,927
130,307
148,072
159,279
163,519
167,378
164,579
159,533
147,681
Percentage matched to the PNC
90.8%
92.4%
93.4%
93.5%
96.8%
98.0%
98.6%
98.7%
99.1%
99.3%
99.3%
99.4%
Percentage matched to the PNC and index 
77.7%
74.4%
75.2%
74.6%
79.6%
84.0%
85.0%
86.2%
87.3%
88.3%
89.0%
89.0%
offences (not breach etc.)
YJB2
YJB discharges
-
1,337
1,612
1,521
1,551
1,564
1,553
1,647
1,626
1,770
891
836
Automatically matched to the PNC
-
1,226
1,502
1,425
1,448
1,464
1,463
1,537
1,564
1,682
852
801
Matched to an index date
-
680
818
785
800
769
780
845
817
916
647
607
Percentage matched to the PNC
-
91.7%
93.2%
93.7%
93.4%
93.6%
94.2%
93.3%
96.2%
95.0%
95.6%
95.8%
Percentage matched to the PNC and index 
-
50.9%
50.7%
51.6%
51.6%
49.2%
50.2%
51.3%
50.2%
51.8%
72.6%
72.6%
offences (not breach etc.)

 

 
1. Data are not available for 2001 due to a problem with archived data on Court Orders. 2. A new data collection method began in March 2012. 
 
 
The total number of offenders matched to the PNC is substantially higher than the final figure for the cohorts - for example, in 2012 there were 252,071 matched offenders, but a final cohort size of 219,347. The main reasons for these discrepancies are: 
 

 Conviction dates for the beginning of the community, suspended or 
custodial sentence do not match the conviction date within seven days of the criminal records from the PNC database; 
 The index offence was not dealt with by a Home Office police force - 
this ensures that only offences in England and Wales are counted; 
 Exclusion of all offenders where the index offence is a breach, since 
we are only interested in new offences; and 
 Exclusion of multiple offender entries (see section above titled 
"Multiple offender entries" for further details). 

## Counting Rules

The counting rules for choosing which prison discharges to include offer a variety of choices. For instance, it makes little sense to include offenders deported on release or who have died. These counting rules were enumerated and discussed to ensure a more accurate and consistent count and are reviewed on an annual basis to ensure a consistent approach. Note that an offender is counted more than once when the offender was initially in the juvenile cohort, then in the adult cohort in the same cohort period. 

 
Complexity of data processing and analysis The data processing involved for measuring reoffending is complex. To analyse reoffending behaviour by previous offending or disposal history requires the extraction of criminal histories that can span a number of decades, and the subsequent matching of these histories against the probation caseload files and prison discharges in order to generate a dataset. 

The extraction of the criminal histories To quality assure the extraction of criminal histories, a small set of random samples of offenders was taken after the analysis to check, via a basic validation, that outputs of the SQL (Structured Query Language) program were accurate. The Ministry of Justice is confident that this process has been successful. 

 

## Level Of Subjectivity

There is relatively little subjectivity in the system. Occasional judgements are required (e.g. where to classify an offence), but these will not significantly influence the results. 

## Maturity And Stability Of The Data System

The system is well established having been used a number of times to produce reoffending statistics for publication. Nonetheless, vigilance continues to be exercised to ensure the validity of the results. 

Expertise of those who operate the system Prison and court order data-feeds are continually monitored and improvement work is regularly undertaken to improve the reliability and the accuracy of datasets. The internal processing of the results within the Ministry of Justice has been subject to dip sampling of criminal histories and the statistical model has been extensively tested. 

Interpreting trends in the proportion of offenders who commit a serious reoffence against the person Care should be taken when interpreting the severity rate for the following reasons: 

 **Time through the Criminal Justice System** - more serious 
offences are likely to take a longer time to progress through the Criminal Justice System than less serious offences. The proven reoffending statistics track proven reoffending behaviour for a year upon offenders entering the cohort, plus an additional six months for convictions to be updated on the system. There is a risk that this time scale is not long enough to capture the most serious offences. However, analysis suggests that the number of serious proven reoffences picked up by the measure remains comparatively stable year on year, ensuring performance is comparable over time. 
 **Reporting variation** - variation in reporting time between police 
force areas and courts may also have an impact on how many serious offences are captured during the one year follow-up period. 

## Data On Historical Trends

The data used to measure proven reoffending is from the PNC. Police forces started to enter criminal records locally in 1995. In order to allow time for good practice among police forces in entering data onto the PNC to become embedded, PNC data was used to measure proven reoffending for the first time in 2000. Prior to the 2012, headline bulletin results were compared to 2000 to highlight long-term trends. From 2012, results are compared to 2002, and in the future the year of comparison will move forward by one year for each calendar year publication. Results prior to 2000 cannot be compared to results from 2000 onwards for two main reasons: 

 Change in data source - reoffences are measured using data from 
the PNC (which covers recordable offences), whereas data from years before 2000 were measured using the offenders index (which covered a narrower range of offences). 
 Change in measurement - the concept being measured from 2000 
onwards in these reports is that of using the offence date to measure reoffences (a period of time is allowed for offences to be committed, and a further period allowed for these offences to be proved by caution, reprimand, final warning or court conviction), whereas the concept being measured prior to 2000 was that of using the conviction date to measure reconvictions (any conviction occurring in a set period of time, whether or not the offence occurred in that time period). 
 However, the *Compendium of Reoffending Statistics and Analysis 2010*, published in November 2010, provides the most consistent statistical series possible between 1971 and 2006, adjusting for known methodological changes. For more information, please refer to Chapter 4.4 at the following link. Results for 2001 cannot be calculated for offenders on court orders because of a problem with archived data on court orders. Local breakdowns of the headline proven reoffending rates are available from 2005 onwards. Proven reoffending data are broken down by locality using the address and post-code information of the offender. Where this information is missing, the location of the processing police force is used instead. This is not a completely reliable indicator of the offender's home address as offenders may offend in a different locality than where they reside. The completeness of this information has improved over time. In 2000, this information was omitted for 29% of cases, which was considered too high to produce reliable results. By 2005, this was reduced to 16.5%, and there has been a continuing downward trend since then. 



Confidentiality This statement sets out the arrangements in place for protecting persons' 
confidential data when statistics are published or otherwise released into the public domain. Principle 5 of the Code of Practice for Official Statistics states that: 

Private information about individual persons (including bodies corporate) compiled in the production of official statistics is confidential and should be used for statistical purposes only.  
 It also states that arrangements for confidentiality protection should be:  
 

sufficient to protect the privacy of individual information, but not so restrictive as to limit unduly the practical utility of official statistics.  
 To comply with this and with the Data Protection Act of 1998, and to maintain the trust and co-operation of those who use reoffending statistics, the following provisions have been put in place. Private information collected by the Ministry of Justice (MoJ) is stored in line with MoJ data security policies. Electronic data are held on password protected networks. All new staff undergo MoJ security vetting before receiving access to data systems, and all staff undertake mandatory training on information responsibility annually. Three types of disclosure risk are considered in relation to reoffending statistics: general attribution, identification (including self-identification) and residual through combination of sources. Assessment of the risk of disclosure considers the following: 

 Level of aggregation (including geographic level) of the data  Size of the population  The likelihood of an attempt to identify  Consequences of disclosure  
 As a result number of offenders, reoffenders, reoffences and previous offences based on five or fewer offenders are suppressed for individual prisons, probation areas and the following geographical areas; County, Upper Tier Local Authority, Lower Tier Local Authority and Youth Offending Team. This is to prevent the disclosure of individual information. 

 

## Appendix A: Glossary Of Terms

Reoffending terms 
 
Cohort - this is the group of individuals whose reoffending is measured. 

 
Index offence - the index offence is the proven offence that leads to an offender being included in the cohort. 

Index disposal - the index disposal of the offender is the type of sentence the offender received for their index offence. 

 
Start point (index date) - this is the set point in time from when reoffences are measured. 

Follow-up period - this is the length of time proven reoffending is measured over. 

Waiting period - this is the additional time beyond the follow-up period to allow for offences committed towards the end of the follow-up period to be proved by a court conviction, caution, reprimand or final warning. 

Reconviction - where an offender is convicted at court for an offence committed within a set follow-up period and convicted within either the follow-up period or waiting period. 

Proven reoffence - where an offender is convicted at court or receives some other form of criminal justice sanction for an offence committed within a set follow-up period and disposed of within either the follow-up period or waiting period. 

 
Cohort definition used in the Proven Reoffending Statistics Quarterly Bulletin - the proven reoffending cohort consists of all offenders discharged from custody, otherwise sanctioned at court, receiving a caution, reprimand or warning in each year. This cohort's criminal history is collated and criminal behaviour is tracked over the following one year. Any offence committed in this one year period which is proven by a court conviction or out-of-court disposal (either in the one year period, or in a further six months waiting period) counts as a proven reoffence.  
Cohort definition used in the Interim Proven Reoffending Statistics for CRCs and NPS Quarterly Bulletin - the payment by results proven reoffending cohort consists of all adult offenders in any one quarter (January to March, April to June, July to September, October to December) who begin a community order, a suspended sentence order or who were released from custody. This cohort's criminal behaviour to date is tracked and collated. Any offence committed in this period which is proven by a court conviction or out-of-court disposal counts as a proven reoffence. 

 
Cohort definition used in the Local Adult Reoffending Quarterly Bulletin - the local adult reoffending measure takes a snapshot of all offenders, aged 18 or over, who are under probation supervision at the end of a quarter, and combines four such snapshots together. This cohort's criminal history is collated and criminal behaviour is tracked over the following three months. Any offence committed in this three month period which is proven by a court conviction or out-of-court disposal (either in the three month period, or in a further three months waiting period) counts as a proven reoffence. The latest available publication is available at this link. 

Disposal (sentence type) 
 
Fine - a financial penalty imposed following conviction. 

 
Court orders - court orders include community sentences, community orders and suspended sentence orders supervised by the Probation Service. They do not include any pre or post release supervision. 

Criminal Justice Act 2003 (CJA03) - for offences committed on or after 4 
April 2005, the new community order replaced all existing community sentences for adults. The Act also introduced a new suspended sentence order for offences which pass the custody threshold. It also changed the release arrangements for prisoners. See Appendix A of Offender Management Caseload Statistics 2009 for more information. 

Community order - for offences committed on or after 4 April 2005, the new community order introduced under the CJA 2003 replaced all existing community sentences for those aged 18 years and over. This term refers to all court orders except suspended sentence orders and deferred sentences which may have a custodial component to the sentence. The court must add at least one, but could potentially add all 12 requirements depending on the offences and the offender. The requirements are: 
 

 unpaid work (formerly community service/community punishment) - a 
requirement to complete between 40 and 300 hours' unpaid work; 
 
 activity - for example, to attend basic skills classes; 
 
 programme - there are several designed to reduce the prospects of 
reoffending; 
 
 prohibited activity - a requirement not do so something that is likely 
to lead to further offence or nuisance; 
 
 curfew - which is electronically monitored; 
 
 exclusion - this is not used frequently as there is no reliable 
electronic monitoring yet available; 
 
 residence - requirement to reside only where approved by probation 
officer; 
 
 
 mental health treatment (requires offender's consent); 
 
 drug rehabilitation (requires offender's consent); 
 
 alcohol treatment (requires offender's consent); 
 
 supervision - meetings with probation officer to address 
needs/offending behaviour; and 
 
 attendance centre - between a minimum of 12 hours and a maximum 
of 36 in total which includes three hours of activity. 
 Typically, the more serious the offence and the more extensive the offender's needs, the more requirements there will be. Most orders will comprise of one or two requirements, but there are packages of several requirements available where required. The court tailors the order as appropriate and is guided by the Probation Service through a pre-sentence report. 

Suspended sentence order **(SSO)** - the CJA 2003 introduced a new suspended sentence order which is made up of the same requirements as a community order and, in the absence of breach is served wholly in the community supervised by the Probation Service. It consists of an 'operational period' (the time for which the custodial sentence is suspended) 
and a 'supervision period' (the time during which any requirements take effect). Both may be between six months and two years and the 'supervision period' cannot be longer than the 'operational period', although it may be shorter. Failure to comply with the requirements of the order or commission of another offence will almost certainly result in a custodial sentence. 

Pre CJA03 Court Orders - Community sentences 
 
Community punishment order **(CPO)** - the offender is required to undertake unpaid community work. 

Community rehabilitation order **(CRO)** - a community sentence which may have additional requirements such as residence, probation centre attendance or treatment for drug, alcohol or mental health problems. 

Community punishment and rehabilitation order **(CPRO)** - a community sentence consisting of probation supervision alongside community punishment, with additional conditions like those of a community rehabilitation order. 

Custody - the offender is awarded a sentence to be served in prison or a Young Offenders Institute (YOI). If the offender is given a sentence of 12 months or over, or is aged under 22 on release, the offender is supervised by the Probation Service on release. It is important to note that the sentence lengths and youth disposals awarded will be longer than the time served in custody. For more information please refer to Appendix A of Offender Management Caseload Statistics 2009. 

 
Short sentences (under 12 months) - those sentenced to under 12 
months (made under the Criminal Justice Act 1991) spend the first half of their sentence in prison and are then released and considered 'at risk' for the remaining period. This means they are under no positive obligations and do not report to the Probation Service, but if they commit a further imprisonable offence during the 'at risk' period, they can be made to serve the remainder of the sentence in addition to the punishment for the new offence. The exception to this is those aged 18 to 20 who have a minimum of three month's supervision on release. 

Sentences of 12 months or over - the CJA03 created a distinction between standard determinate sentences and public protection sentences. Offenders sentenced to a standard determinate sentence serve the first half in prison and the second half in the community on licence. 

Youth disposal (sentence type) 
 
Reprimand or warning - a reprimand is a formal verbal warning given by a police officer to a juvenile offender who admits they are guilty for a minor first offence. A final warning is similar to a reprimand, but can be used for either the first or second offence, and includes an assessment of the juvenile to determine the causes of their offending behaviour and a programme of activities is designed to address them. Reprimands and warnings for youths were abolished under Legal Aid Sentencing and Punishment of Offenders Act 2012 with effect from 8 April 2013 and replaced with youth cautions. 

Youth cautions - are a formal out-of-court disposal that can be used as an alternative to prosecution for young offenders (aged 10 to 17) in certain circumstances. A Youth Caution may be given for any offence where the young offender admits an offence, there is sufficient evidence for a realistic prospect of conviction but it is not in the public interest to prosecute.  
 
First-tier penalties 
 
Discharge - a juvenile offender is given an absolute discharge when they admit guilt, or are found guilty, with no further action taken. An offender given a conditional discharge also receives no immediate punishment, but is given a set period during which, if they commit a further offence, they can be brought back to court and re-sentenced. 

 **Fine** - the size of the fine depends on the offence committed and the 
offender's financial circumstances. In the case of juveniles under 16, the fine is the responsibility of the offender's parent or carer. 
 **Referral order** - this is given to juveniles pleading guilty and for 
whom it is their first time at court (unless the offence is so serious it merits a custodial sentence or it is of a relatively minor nature). The offender is required to attend a Youth Offender Panel to agree a contract, aimed to repair the harm caused by the offence and address the causes of the offending behaviour. 
 

 **Reparation order** - the offender is required to repair the harm 
caused by their offence either directly to the victim or indirectly to the community. 
 
Youth Rehabilitation Order - a community sentence for juvenile offenders, which came into effect on 30 November 2009 as part of the Criminal Justice and Immigration Act 2008. It combines a number of sentences into one generic sentence and is the standard community sentence used for the majority of children and young people who offend. The following requirements can be attached to a Youth Rehabilitation Order (YRO): 

 activity requirement  curfew requirement  exclusion requirement  local authority residence requirement  education requirement  mental health treatment requirement  unpaid work requirement  drug testing requirement  intoxicating substance misuse requirement  supervision requirement  electronic monitoring requirement  prohibited activity requirement 
 drug treatment requirement 
 residence requirement  programme requirement  attendance centre requirement  intensive supervision and surveillance  intensive fostering 
 The following community sentences are replaced by the YRO, but will continue to exist for those that committed an offence before 30 November 2009. The YRO is only available for those that committed an offence on or after the 30 November 2009. 

 action plan order  curfew order  supervision order  supervision order and conditions 
 

 community punishment order  community punishment and rehabilitation order  attendance centre order 
 drug treatment and testing order  exclusion order  community rehabilitation order 
 
Prison categories 
 
Category B and category C **prisons** hold sentenced prisoners of their respective categories, including life sentenced prisoners. The regime focuses on programmes that address offending behaviour and provide education, vocational training and purposeful work for prisoners who will normally spend several years in one prison. 

High security prisons hold category A and B prisoners. Category A 
prisoners are managed by a process of dispersal, and these prisons also hold a proportion of category B prisoners for whom they provide a similar regime to a category B prison. The category B prisoners held in a High Security Prison are not necessarily any more dangerous or difficult to manage than those in category B prisons. 

Female prisons, as the name implies, hold female prisoners. Because of the smaller numbers, they are not divided into the same number of categories although there are variations in security levels. 

Local prisons serve the courts in the area. Historically their main function was to hold un-convicted and un-sentenced prisoners and, once a prisoner had been sentenced, to allocate them on to a category B, C or D prison as appropriate to serve their sentence. However, pressure on places means that many shorter term prisoners serve their entire sentence in a local prison, while longer term prisoners also complete some offending behaviour and training programmes there before moving on to lower security conditions. All local prisons operate to category B security standards. 

Open prisons have much lower levels of physical security and only hold category D prisoners. Many prisoners in open prisons will be allowed to go out of the prison on a daily basis to take part in voluntary or paid work in the community in preparation for their approaching release. Miscellaneous terms 
 
National Probation Service - the National Probation Service generally deals with those aged 18 years and over. (Those under 18 are mostly dealt with by Youth Offending Teams, answering to the Youth Justice Board.) They are responsible for supervising offenders who are given community sentences and suspended sentence orders by the courts, as well as offenders given custodial sentences, both pre and post their release. 

 
Police National Computer - the Police National Computer (PNC) is the police's administrative IT system used by all police forces in England and Wales and managed by the National Policing Improvement Agency. As with any large scale recording system the PNC is subject to possible errors with data entry and processing. The Ministry of Justice maintains a database based on weekly extracts of selected data from the PNC in order to compile statistics and conduct research on reoffending and criminal histories. The PNC largely covers recordable offences - these are all indictable and triable-either-way offences plus many of the more serious summary offences. All figures derived from the Ministry of Justice's PNC database, and in particular those for the most recent months, are likely to be revised as more information is recorded by the police. 

Recordable offences - recordable offences are those that the police are required to record on the PNC. They include all offences for which a custodial sentence can be given plus a range of other offences defined as recordable in legislation. They exclude a range of less serious summary offences, for example television licence evasion, driving without insurance, speeding and vehicle tax offences. 

Offence group (based on new ONS crime classifications) - offences classified into 13 separate offence categories using the new Office for National Statistics (ONS) crime classifications. 

Indictable and summary offences - Proven reoffending statistics quarterly (published 28 July 2016) included a table (B1.1) on serious sexual/violent proven reoffences and serious acquisitive proven reoffences. Another way to classify the seriousness of an offence is to classify the offence as 'summary', 'triable-either-way' or 'indictable-only'. Indictable-only offences cover the most serious offences that must be tried at the Crown Court; these 'indictable-only' offences include murder, manslaughter, rape and robbery. These are reported in table B1. Note that summary offences are triable only by a magistrates' court. This group includes motoring offences, common assault and criminal damage up to £5,000. Triableeither-way offences are more serious offences; these can be tried either at the Crown Court or at a magistrates' court, and include criminal damage where the value is £5,000 or greater, theft and burglary. Summary and triable-either-way are not reported. 

Youth Offending Teams (YOTs) 
YOTs work with young people that get into trouble with the law and each one cover a certain number of local authorities. The YOTs have been updated in the proven reoffending publication published on the 28th July 2016. 

## Explanatory Notes

The United Kingdom Statistics Authority has designated these statistics as National Statistics, in accordance with the Statistics and Registration Service Act 2007 and signifying compliance with the Code of Practice for Official Statistics. Designation can be broadly interpreted to mean that the statistics: 

 meet identified user needs;  are well explained and readily accessible;  are produced according to sound methods; and  are managed impartially and objectively in the public interest. 
 
Once statistics have been designated as National Statistics it is a statutory requirement that the Code of Practice shall continue to be observed. 

## Symbols Used

| ..     | Not available                                          |
|--------|--------------------------------------------------------|
| 0      | Nil or less than half the final digit shown            |
| -      | Not applicable                                         |
| *      | One or both of the comparison figures are less than 30 |
| (p)    | Provisional data                                       |


## Contact Details

 
For queries, comments or further information, please contact: 
Nick Mavron Ministry of Justice Justice Statistics Analytical Services 7th floor 102 Petty France London SW1H 9AJ Email: statistics.enquiries@justice.gsi.gov.uk 
 
Alternative formats are available on request from statistics.enquiries@justice.gsi.gov.uk. 

## © Crown Copyright 2015

This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gsi.gov.uk. 

##