Self-harm in prison custody


Last updated 14 May 2019 - see all updates

1. Main facts and figures

  • overall, self-harm incidents among prisoners increased for all ethnic groups between 2012 and 2017
  • there was a higher rate of self-harm in prisoners from the White ethnic group than in any other ethnic group
  • between 2012 and 2017, the rate of self-harm among prisoners from a Mixed ethnic background more than doubled
Things you need to know

This data records the number of times an act of self-harm was reported, not the number of prisoners that self-harmed or how often prisoners harmed themselves. Prisoners may therefore be included in the data more than once. This means that the rate of self-harm per 1,000 prisoners should be considered with some caution.

Estimates based on a larger number of prisoners are generally more reliable. The smaller numbers of prisoners from the Asian, Black, Mixed and Other ethnic groups mean that estimates for these groups are less reliable than estimates for White prisoners.

In earlier versions of this measure, prisoners from the Chinese ethnic group were counted either in 'Asian or Asian British' or 'Other' depending on the code selected. Figures have now been updated to include Chinese under 'Asian or Asian British.

What the data measures

The data measures the number and rate of incidents of self-harm per 1,000 prisoners in England and Wales per year from 2012 to 2017. The data is broken down by ethnicity.

Self-harm in prison custody is defined as any act where a prisoner deliberately harms themselves, regardless of how they do so, what their intent is or how badly they injure themselves.

The ethnic categories used in this data

Prisoners reported their own ethnicity according to the following broad categories from the 2011 Census:

  • Asian/Asian British
  • Black/African/Caribbean/Black British
  • Mixed/Multiple ethnic groups
  • White
  • Other

2. By ethnicity over time

Self-harm incidents per 1,000 prisoners by ethnicity over time
Time Asian Black Mixed White Other
Self-harm incidents per 1,000 prisoners Self-harm incidents per 1,000 prisoners Self-harm incidents per 1,000 prisoners Self-harm incidents per 1,000 prisoners Self-harm incidents per 1,000 prisoners
2012 91 65 136 325 157
2013 98 72 198 326 213
2014 83 72 231 363 185
2015 124 81 274 450 225
2016 146 94 387 551 347
2017 148 100 328 621 357

Download table data for ‘By ethnicity over time’ (CSV) Source data for ‘By ethnicity over time’ (CSV)

Summary of Self-harm in prison custody By ethnicity over time Summary

This data shows that:

  • in 2017, the highest rate of self-harm in prisons was among White prisoners, with 621 incidents per 1,000 prisoners
  • prisoners from the Other ethnic group had the next highest rate of self-harm, at 357 incidents per 1,000 prisoners
  • Black prisoners had the lowest rates of self-harm, at 100 incidents per 1,000 prisoners
  • between 2012 and 2017, the rate of self-harm amongst prisoners from a Mixed ethnic background increased from 136 to 328 incidents per 1,000 prisoners

3. Methodology

Normally, to calculate the prisoner population, a 12-month average (based on prisoner counts done at the start of every month) is used where this data is available. This data was not available broken down by age or by ethnicity, so in this case quarterly data has been used to calculate the prisoner population.

Ethnicity was recorded for more than 95% of incidents of self-harm. Because of the very small number of incidents of self-harm where ethnicity is not known, this data has been excluded from the analysis.

Information is provided by prisons and published by the Ministry of Justice after data checks are completed.

Suppression rules and disclosure control

Values of 2 or fewer prisoners have been suppressed to protect confidentiality. (No incident numbers have been suppressed.)


Rates per 1,000 are rounded to the nearest whole number.

Related publications

Safety in custody statistics

Quality and methodology information

4. Data sources


Type of data

Administrative data

Type of statistic

Official statistics


Ministry of Justice

Publication frequency


Purpose of data source

This data is used by government to:

  • inform policy development
  • monitor the impact of changes over time
  • model future changes and their impact on the prison system

5. Download the data

self_harm_in_custody_adults - Spreadsheet (csv) 2 KB

This file contains the following: ethnicity, year and value