Cause of Death in Prison Custody

(Supplementary Tables B1 to B15)

In this section we cover the following topics:

• Summary of Causes of Death in Prison Custody
• Probable Suicide Deaths
• Diseases of the Circulatory System Deaths
• Drug Misuse Deaths and Accidents
• Deaths from Other Causes
• Cancer (malignant neoplasms) Deaths and
• Deaths Involving COVID-19

Summary of Causes of Death in Prison Custody

When a death is registered with National Records of Scotland (NRS), each cause of death listed on the medical certificate of cause of death (MCCD) is assigned a code from the International Statistical Classification of Diseases and Related Health Problems (10th Revision) (ICD-10). Following the classification schema, one cause will be defined as the underlying cause of death or the “disease or injury which initiated the chain of morbid events leading directly to death”. NRS statistics are based on the underlying cause of death unless stated otherwise. More information about Death Certificates and Coding the Causes of Death and how NRS attribute cause of death to a case can be found on the NRS website.

Individual cause of death codes can be grouped together to produce analysis of broader causes of death, such as diseases of the circulatory system or probable suicide. NRS publish statistics for specific causes of death, on the basis of pre-defined groupings of death codes.

The following table provides a breakdown of deaths in prison custody by cause of death for the period 2012-13 to 2023-24. All causes are based on the underlying cause of death, with the exception of COVID-19, which is based on any mention on the MCCD.

Table 1 shows the total count of each cause of death over the period 2012-13 to 2023-24.

Cause of Death	Number of Cases
Probable Suicide	115
Diseases of the circulatory system	83
Accidents	62
Drug Misuse	62
Other causes	54
Cancer (malignant neoplasms)	47
Ischaemic (coronary) heart disease	44
Cerebrovascular disease	18
COVID-19 mentioned	17
Diseases of the respiratory system	17
Chronic Obstructive Pulmonary Disease	9
Alcohol specific	2
Dementia and Alzheimer’s disease	0

Supplementary table B2 lists the ICD-10 codes that are used to define each cause of death.

Please note that the sum of the deaths by cause is higher than the total number of deaths. This is because some deaths are attributed to more than one cause. As an example, a death that has been classified as Chronic Obstructive Pulmonary Disease (ICD-10 codes J40-44) will also be counted as Diseases of the respiratory system (ICD-10 codes J00-99).

The following table sets out the combinations of overlapping causes of death in prison custody over 2012-13 to 2023-24, and how often each occurs over this reporting period.

Table 2 shows all combinations of multiple causes of death from all deaths in prison custody between 2012-13 and 2023-24.

Cause of Death Combination	Number
Drug misuse and Accidents	57
Diseases of the circulatory system and Ischaemic (coronary) heart disease	44
Diseases of the circulatory system and Cerebrovascular disease	18
Diseases of the respiratory system and Chronic Obstructive Pulmonary Disease (COPD)	9
COVID-19 mentioned and Diseases of the circulatory system	1
Drug misuse and Probable suicide	1
COVID-19 mentioned, Diseases of the Circulatory system and Ischaemic Heart Disease	1

The most frequently occurring causes of deaths in prison custody are examined in further detail in this report.

It is important to note that due to the total number of cases being charted over the 12-year period being relatively small, small volume changes in the number for any year may appear as a substantial change.

Probable Suicide Deaths

(Supplementary Tables B4 to B6)

Probable suicide deaths are identified based on the underlying cause of death and additional information. NRS determine whether a death is a probable suicide using the MCCD and information provided by official sources such as the Crown Office and Procurator Fiscal Service. The methodology document that accompanies the NRS publication provides more detail about the specific ICD-10 codes that relate to probable suicide deaths.

This methodology document also sets out that the ICD has separate categories for deaths that can be used depending on the available information. These categories are ‘Intentional Self-Harm”, and “Events of Undetermined Intent”. Events of undetermined intent are “cases where it is not clear whether the death was the result of intentional self-harm, an accident or an assault”(p.3). Because of this, the number of suicides may be over-estimated.  

Between 2012-13 and 2023-24, 115 deaths in prison custody were classified as probable suicide. This is the most common cause of death in prison custody over the reporting period, with probable suicides accounting for around 29% of deaths in prison custody from 2012-13 to 2023-24 (n = 399).  In 2023-24 there were 10 probable suicide deaths, +1 from 2022-23 (9).

Figure 7 shows the number of the number of probable suicide deaths in prison custody in each year between 2012-13 and 2023-24.

The number of probable suicide deaths in each financial year fluctuates across the reporting period. The highest number of probable suicides in prison custody occured in both 2016-17 and 2021-22 with 15 such deaths recorded in each year.

While there is a general upward trend in the overall number of deaths in prison custody across the period 2012-13 to 2023-24, the number of probable suicide deaths has not followed the same pattern (figure 8). However, the number of probable suicide deaths year on year is at a slightly increased level from 2016-17 to 2023-24 when compared against the earlier years in the reporting period.

Figure 8 shows probable suicide deaths in prison custody plotted alongside all deaths in prison custody, 2012-13 to 2023-24.

Method of Suicide

(Supplementary Table B6)

Probable suicide deaths can be classified by method. In their latest probable suicide publication, NRS group probable suicide deaths into three broad categories: ‘Hanging, strangulation, suffocation’, ‘Poison’, and ‘Other’. The table below shows the probable suicide deaths that occurred in prison custody between 2012-13 and 2023-24 categorised by method.

Table 3 shows the method of suicide by NRS category for all probable suicide deaths in prison custody between 2012-13 and 2023-24.

Method of Suicide	Number of Cases	Proportion of Probable Suicide Deaths
Hanging, strangulation, suffocation	104	90.4%
Other	7	6.1%
Poison	4	3.5%

Over 90% of probable suicide deaths occuring in prison custody from 2012-13 to 2023-24 have an underlying cause of ‘X70 Intentional self-harm by hanging, strangulation and suffocation’. This overall trend is consistent with the NRS Probable Suicide report, with hanging, strangulation and suffocation noted as the most common method in probable suicide deaths in the general population over the same time.

If you are a journalist covering these statistics in the media, please consider following the guidelines issued by Samaritans on the reporting of suicide.

If you are struggling to cope, help is available.

NHS inform has a list of resources available to anyone, with many of these available 24 hours a day.

Samaritans can be called for free on 116 123 (UK and Republic of Ireland) or contacted via email at jo@samaritans.org. Visit the Samaritans website for more information.

Diseases of the Circulatory System Deaths

(Supplementary Table B7)

The second most frequent cause of death between 2012-13 and 2023-24 was Diseases of the Circulatory System (ICD-10 codes I00-I99). 83 of the deaths that occurred in prison custody over this period were caused by circulatory system diseases (20.8% overall, n=399). In 2023-24, 12 deaths in prison custody were recorded as circulatory system diseases, +2 from 2022-23 (10).

Figure 9 shows the number of deaths in prison custody caused by diseases of the circulatory system in each year, 2012-13 to 2023-24.

This chart shows fluctuation in the number of circulatory system deaths in prison custody year on year, with the peak (12) occuring in 2023-24. While there has been an increase in recent years, there is no clear overall trend across the time period.

44 deaths caused by diseases of the circulatory system between 2012-13 and 2023-24 were also classified as Ischaemic (coronary) heart disease, while 18 were associated with Cerebrovascular disease. Around 75% of diseases of the circulatory system deaths that occurred in prison custody between 2012-13 and 2023-24 fell into either of these subsets.

Drug Misuse Deaths

(Supplementary Tables B8 to B10)

Drug related deaths in Scotland are categorised as drug misuse deaths. As explained in the latest NRS Drug Related Deaths publication, this term has been defined by the Advisory Council on the Misuse of Drugs cross UK working group.

Drug misuse deaths are those with an underlying cause of mental and behavioural disorders due to drug use, or where the underlying cause was poisoning and there was a controlled drug present in the body. ‘Controlled drugs’ are those that are listed under the Misuse of Drugs Act (1971). This definition covers both recreational drugs, and some prescribed drugs.

A death is only categorised as a drug misuse death where the drug use has directly caused the death. NRS consult with experts in Public Health Scotland to determine whether individual deaths meet the definition of a drug misuse death. More information about NRS classsification of drugs deaths can be found in their methodology documents. Information about the ICD-10 codes that relate to drug misuse deaths can be found in Annex A of the methodological documents produced by NRS.

Between 2012-13 and 2023-24, there were 62 drug misuse deaths in prison custody. This represents around 15.5% of all deaths in prison custody across the reportingperiod (n = 399). In 2023-24 there were 12 drug misuse deaths in prison custody, +3 from 2022-23 (9).  

Figure 10 shows the number of drug misuse deaths in prison custody in each year between 2012-13 and 2023-24.

While there are fluctuations year to year, the number of drug misuse deaths in prison custody has increased over the reporting period.

The general increase in drug misuse deaths in prison custody is similar to the trend observed in the general population over the time period. However, as seen in their latest Drug-related Deaths publication, NRS figures show that the number of drug related deaths in the general population has fallen in 2024.

Substances

(Supplementary Tables B9 and B10)

For this report, information on the substances identified in drug misuse deaths in prison custody has been taken from the information on the medical certificate of cause of death (MCCD) published by the Scottish Prison Service (SPS). This information was not published by SPS prior to 2019. Therefore this section only covers the 43 drug misuse deaths in prison custody from 2019 onwards, rather than the 62 drug misuse deaths recorded over the full reporting period (2012-13 to 2023-24).

The information on the MCCD is checked and expanded upon by NRS when drug misuse deaths are coded. NRS receive information from pathologists on the substances involved in drug misuse deaths, which may contain more detail than is available from the MCCD.

For future reporting, the complete information on substances identified in all deaths will be sought.

The following table provides a count of the different substances identified on the MCCD in all drug misuse deaths in prison custody from 2019 to 2023-24 (43 of 226). The number of substances is greater than the number of deaths that have occurred due to multiple substances being identified in some cases. In 40 of the 43 (around 93%) drug misuse deaths that occurred, multiple substances were listed on the MCCD or reference was simply made to ‘multi-drug intoxication/ toxicity’.

Table 4 shows the tally of each individual substance listed on a death certificate for all drug misuse deaths between 2019 and 2023-24.

Substance	Group	Count
Etizolam	Benzodiazepine	14
Multi Drug Toxicity/ Intoxication	Multi Drug Toxicity/ Intoxication	12
Buprenorphine	Opiate/ Opioid	11
Cocaine	Cocaine	6
Pregabalin	Gabapentin/ Pregabalin	6
Methadone	Opiate/ Opioid	6
Heroin	Opiate/ Opioid	4
Bromazolam	Benzodiazepine	3
Tramadol	Opiate/ Opioid	3
Amitriptyline	Other	3
Flubromazolam	Benzodiazepine	2
Diazepam	Benzodiazepine	2
Flubromazepam	Benzodiazepine	2
Dihydrocodeine	Opiate/ Opioid	2
Synthetic Cannabinoid Receptor Agonist	Synthetic Cannabinoid	2
MDMB-4en-PINACA	Synthetic Cannabinoid	2
Flualprazolam	Benzodiazepine	1
Phenazepam	Benzodiazepine	1
Alprazolam	Benzodiazepine	1
Gabapentin	Gabapentin/ Pregabalin	1
Codeine	Opiate/ Opioid	1
Oxycodone	Opiate/ Opioid	1
Opiate Intoxication	Opiate/ Opioid	1
Nefopam	Other	1
Propranolol	Other	1
Quetiapine	Other	1
4F-MDMB-BINACA	Synthetic Cannabinoid	1
5F-MDMB-PICA	Synthetic Cannabinoid	1

For summary purposes, substances can be categorised by the family of drugs each belongs to.

Figure 11 shows the prevalence of substances listed in the 43 drug misuse deaths that occurred in prison custody between 2019 and the end of 2023-2024 that contain substance information.

From the information available, the most common type of substance identified on the MCCD in deaths in prison custody from 2019 onwards are ‘Opiates/Opioids’. These are identified in 29 of the 43 drug misuse deaths in prison custody that note the presence of substances (around 67%).

Twenty six of the deaths occurring in prison custody that note the presence of substances from 2019 onwards (around 60%) had a form of Benzodiazepines recorded on the MCCD.

Full information from NRS records on drug misuse deaths occurring in prison custody is needed to explore these patterns further.

Substances may also be listed for deaths that are not classified as drug misuse deaths. The methodological annex that accompanies the Drug Related Deaths in Scotland 2024 publication produced by NRS provides more information on the criteria that would exclude a death as being classified as drug misuse.

The substances listed in these cases are excluded from the analysis above. More information can be found on the SPS website.

Drug Misuse and Accidents

(Supplementary Table B11)

There is a considerable overlap between deaths in prison custody categorised as drug misuse and those categorised as accidents. A death may be classified as an accident due to the perceived underlying intent behind the mortality. This could be due to the death being a result of an accidental overdose

Sub chapter V01 – X59 of chapter XX in the ICD-10 provides more information of the circumstances that may result in a death being ascribed as an accident.

Of the 62 drug misuse deaths that occurred in prison custody between 2012-13 and 2023-24, 57 were also categorised as accidents (92%).

The venn diagram below illustrates this overlap.

Figure 12 shows a venn diagram illustrating the overlap between drug misuse and accidental deaths in prison custody,  2012-13 to 2023-24.

Looking at the individual ICD-10 codes, this shows that 57 of the drug misuse deaths within the prison population were due to accidental poisonings involving various substances. Of the cases that were not classed as an accidental poisoning, four were recorded as resulting from ‘mental and behavioural disorders’ due to multiple drug use and use of other psychoactive substances, and the use of cannabinoids, and one was a poisoning of undetermined intent. 

The high proportion of drug misuse deaths in prison custody being classified as an accidental poisoning is broadly consistent with the trend found in the general population.

Deaths from Other Causes

(Supplementary Table B12)

Table 1 of this report shows that 54 deaths in prison custody (around 13.5%) between 2012-13 and 2023-24 were categorised as deaths from ‘other causes’. There were 4 deaths from other causes in 2023-24, the same level as the previous year.

Deaths from ‘other causes’ are attributed to a range of different chapters within the ICD-10 framework. 

The table below breaks down the deaths from other causes occurring in prison custody 2012-13 to 2023-24 by the ICD-10 chapters attributed to them.

Table 5 contains a breakdown of ICD-10 chapters attributed to ‘other causes’ of death in prison custody, 2012-13 to 2023-24.

ICD-10 Chapter	Count
XI – Digestive system diseases (K00-K99)	19
XVIII – Symptoms, signs and abnormal clinical and laboratory findings not elsewhere classified (R00-R99)	9
I – Certain infectious and parasitic diseases (A00-B99)	6
IV – Endocrine, nutritional and metabolic diseases (E00-E90)	6
VI – Nervous system diseases (G00-G99)	5
XX – External causes of morbidity and mortality (V01 – Y98)	3
XII – Diseases of the skin and subcutaneous tissue (L00-L99)	2
XIV – Genitourinary system diseases (N00-N99)	2
II – Neoplasms (C00-D48)	1
V – Mental and behavioural disorders (F00-F99)	1

The most common ICD-10 chapter for deaths in prison custody recorded as occurring from ‘other causes’ is XI - Digestive system diseases (K00-K99), attributed to 19 deaths over the period 2012-13 to 2023-24. These deaths are distributed across a range of different sub-chapters.

Cancer (malignant neoplasms)

(Supplementary Tables B13 and B14)

Deaths caused by cancer (malignant neoplasms, listed under ICD-10 codes C00-C97), accounted for 47 (around 11.8%, n = 399) of all deaths in prison custody between 2012-13 and 2023-24. There were 11 deaths caused by cancer in 2023-24, +6 from 2022-23 (5). The number recorded in 2023-24 is the highest in the time series, and is nearly twice the level of the previously observed peak in 2020-21 (6).

Figure 13 shows the number of cancer (malignant neoplasms) deaths in prison custody in each year between 2012-13 and 2023-24.

While the number of cancer (malignant neoplasms) deaths in prison custody have fluctuated year on year, the numbers have been at a generally higher level in the second half of the reporting period. Between 2012-13 and 2017-18 there were 15 cancer (malignant neoplasms) deaths in prison custody, compared to 32 between 2018-19 and 2023-24.

Of the cancer (malignant neoplasms) deaths occurring between 2012-13 and 2023-24, 18 (38.3%) were recorded as malignant neoplasm of bronchus and lung. This is the most common type of cancer recorded for deaths in prison custody. Eleven cancer (malignant neoplasms) deaths in prison custody were categorised as ‘Other’. The category “Other” contains deaths that may fall under sub-categories such as non-Hodgkin’s lymphoma, Leukaemia, and malignant neoplasms of other areas of the body.

Table 6 shows the the most common ICD-10 codes recorded in cancer (malignant neoplasms) deaths in prison custody between 2012-13 and 2023-24.

ICD-10 Codes	Number of Deaths
C34 - Malignant neoplasm of bronchus and lung	18
Other	11
C22 - Malignant neoplasm of liver and intrahepatic bile ducts	4
C61 - Malignant neoplasm of prostate	4
C18 - Malignant neoplasm of oesophagus	4
C80 - Malignant neoplasm without specification of site	3
C18 – Malignant neoplasm of colon	3

Deaths Involving COVID-19

(Supplementary Table B15)

In their monthly mortality statistics methodology document, NRS define a death involving COVID-19 as “any death where COVID-19 is mentioned on the death certificate; this can be as the underlying cause of death or as a contributory factor.” 

In total, there were 17 deaths in prison custody that involved COVID-19 (ICD-10 codes U07.1, U07.2, U09.9, U10.9) between 2020-21 and 2023-24. In 2023-24, there was one death recorded as involving COVID-19.

Figure 14 shows the number of deaths in prison custody involving COVID-19 in each year between 2020-21 and 2023-24.