Risk for intellectual disability populations in inpatient forensic settings in the United Kingdom: A literature review
BACKGROUND Approximately 1.5 million people in the United Kingdom (UK) (2% of the population) have an intellectual disability, defined as “neurodevelopmental disorders that begin in childhood and are characterized by intellectual difficulties as well as difficulties in conceptual, social, and practical areas of living” (American Psychiatric Association, ). This is in line with an estimated global prevalence rate of 2.2% (World Health Organisation, ). As defined in the Forensic Disability Service report (2019) forensic disability services “span the conventional boundaries between disability, mental health and the criminal justice system” (QO, ; p. 6). In the criminal justice system (CJS), people with intellectual disabilities are overrepresented compared to the general population. However, estimates vary due to how intellectual disabilities are defined and recorded (Young et al., ). In the United Kingdom, forensic intellectual disability services are responsible for the assessment, treatment, rehabilitation, and care of patients diagnosed with an intellectual disability (Mental Welfare Commission, ). When a person with a mental health disorder or intellectual disability has committed an offence that could warrant a prison sentence or detention for public safety, a court can decide to detain them under the Mental Health Act (2007) (MHA). In these circumstances, the individual receives treatment in a secure hospital, based on their assessed level of risk. Therefore, this review defines individuals with an intellectual disability, detained under the Mental Health Act, and residing in a secure hospital setting as intellectual disability forensic inpatients. Following the reported abuse of patients with an intellectual disability at Winterbourne View Hospital from February 2008 to May 2011, a review of care across England for people with challenging behaviour was undertaken. The Transforming Care report (UK Department of Health, ) highlighted a failure to implement high‐quality care and deliver outcomes in line with best practice for people with learning disabilities or autism who exhibit challenging behaviour. For example, 73% of Winterbourne patients were detained under the Mental Health Act and faced long periods of detention. Subsequent independent reviews in both England and Scotland into the inclusion of intellectual disabilities and autism within the Mental Health Act raised concerns regarding how this legislation works for people with intellectual disabilities (UK Department of Health, ) (Scottish Government, ). Notably, people with intellectual disabilities face longer periods of detention than those who do not have an intellectual disability, which poses a risk to their human rights (Chester et al., ) (Mental Welfare Commission, ). There is also significant concern that secure ward environments can be unsuitable for people with an intellectual disability and pose a risk to a patient's physical or mental health (Mental Welfare Commission, ). Patients with intellectual disabilities can have difficulty accessing appropriate and prompt support while in acute settings (Marshall‐Tate et al., ), further exacerbating the risks to physical and mental health posed by longer periods of detention. Care planning is a key mechanism by which a patient's care and treatment can be developed, documented and shared. Well‐implemented care planning provides a participatory framework for reviewing the benefits of a treatment programme and enables person‐centred care (Mental Welfare Commission, ). Recent consultations on the reform of the Mental Health Act stress the need for patient preferences to be placed “front and centre” (DoH, , p. 7). People with intellectual disabilities can experience difficulties in learning new information, remembering and processing information, problem‐solving, and developing coping strategies for novel situations. These discrepancies in functioning can compound to create significant barriers to communication (Drainoni et al., ). Being able to contribute meaningfully to care planning requires skills in communicating, processing and weighing up information as well as being able to articulate personal points of view (National Institute for Health and Care Excellence, ). Risk assessment and risk management are major factors in care planning for forensic patients. The Department of Health ( ) Best Practice in Managing Risk defines risk as: ‘relating to the likelihood, imminence and severity of a negative event occurring (i.e., violence, self‐injury, self‐neglect)’ (p. 15). However, research has shown that people with an intellectual disability can perceive risk and protective factors differently, affecting their understanding, communication, and decision‐making around safety (Martí‐Agustí et al., ). This can lead to risky behaviours that may complicate the management of care. Risk assessment instruments in forensic psychiatry often combine actuarial and clinical data, and stress the dynamic nature of risk as well as the importance of situational triggers so that plans and procedures can be put in place to mitigate the possibility of an adverse event occurring. Where there is an identified risk of violence, possible interventions include increased use of de‐escalation techniques, adaptations to the environment, psychological and allied health professional led therapies, and the possibility of seclusion (Long et al., ). Despite the recognition and support among practitioners that patients should be involved in their risk assessment and management (Langan & Lindow, ), there is a significant research gap regarding effective means of engaging patients with an intellectual disability in risk assessment (Markham, ). Although there is some limited evidence drawn from the forensic mental health population (Reynolds et al., ), the experiences of forensic inpatients with an intellectual disability remain under‐researched, despite the communication challenges that this population can often experience. Although there is a growing body of research evaluating risk assessment tools and risk management strategies for people with an intellectual disability in forensic services such as the Historical Clinical Risk Management‐20, Version 3 (Douglas et al., ) and Risk for Sexual Violence Protocol (RSVP) (Hart & Boer, ) (Lindsay et al., ), no literature review has been undertaken to synthesise the evidence on experiences of risk among patients with intellectual disabilities detained under the MHA in forensic inpatient settings. 

AIM The aim of this review was to map and appraise academic evidence on the concept of risk in the context of U.K. forensic services for patients with an intellectual disability. The following objectives underpinned the aim: To identify the forensic and health risks experienced by staff and patients with an intellectual disability in U.K. forensic services. To understand nurses' perceptions of managing risk in U.K. forensic intellectual disability services. To assess the extent to which patients with an intellectual disability can inform their risk assessment and management, and identify factors which may help or hinder this. 

METHODS The literature review was conducted between 1st May 2020 and 26th March 2021. As noted by Turner ( ), interest in forensic risk assessment started to grow around the year 2000 due to the extensive deinstitutionalisation occurring at the time. Therefore, articles included in the literature review were published between 2000 and 2021. The PICOST framework provided a structured approach for developing a research question and search strategy by considering population, intervention, comparison, outcomes, situation, study design and timeframe (Cullum et al., ). The search strategy was further refined through preliminary searches conducted in Google Scholar and Scopus, and consultation with the wider research team. Key search terms included combinations of words such as Learning disab*, Intellectual disab* and Forensic se*, Forensic unit, Forensic facilit* and Risk, Safety. The full search strategy is presented in Table . The identified search terms were combined using Boolean operators and entered into relevant medical, psychology, and social science databases. The bibliographical databases used were CINAHL, OVID, PubMed, Scopus, SocINDEX and Web of Science. When the parameters of an academic database did not facilitate the use of the full search strategy, the strategy was adapted or condensed, and deviations from the original strategy were noted. For example, CINAHL did not allow the input of the full search strategy. Therefore, the term “forensic ward” was removed as it yielded the fewest results. To further supplement database searches, reference lists in publications included for full‐text review were screened, and a free‐hand search was conducted. Results from the databases were exported into Endnote reference management software. The lead reviewer screened titles and abstracts and selected studies for potential inclusion in the review, applying pre‐identified inclusion and exclusion criteria. The criteria for inclusion of articles in this literature review included peer‐reviewed academic papers reporting on issues of risk for people with an intellectual disability, residing in low, medium and high‐secure forensic settings. Any articles that did not directly mention individuals with intellectual disabilities, were not based in adult forensic inpatient settings, or did not report on issues of risk, were not included for review. In the event a study was conducted in more than one setting, for example, a mixture of forensic and community settings, literature was included if it was possible to extrapolate findings relevant to forensic inpatient settings. We did not discriminate based on methodology, providing that the study had been subject to peer review. Expert opinion pieces and relevant grey literature were retained but not included. This provided additional context for the research team but ensured only peer‐reviewed evidence was included in the review. Papers included for review were collated in a table (Table ) according to author, date, title, publication journal, location, aims, participants, interventions, study design, findings, outcomes related to risk, and National Institute for Health and Care Excellence (NICE) quality rating. The NICE appraisal checklist provides a list of criteria for determining the quality of academic publications. This specific tool was chosen as it provides a means of standardising quality ratings across a range of research designs (NICE, ). Papers are designated a quality rating based on the extent to which the NICE criteria are met: all criteria met (++), some criteria met (+) or criteria not met (−). Quality ratings are displayed in Table . Due to variance in study designs and insufficient information to enable meta‐analysis, data were synthesised using a thematic approach. A six‐stage process was used to categorise data into meaningful themes: (1) familiarisation, (2) initial coding, (3) identifying themes, (4) reviewing themes, (5) defining themes and (6) writing up (Braun & Clarke, ). 

RESULTS 4.1 Study characteristics Twenty‐two peer‐reviewed articles around issues of risk in U.K. inpatient forensic settings for people with an intellectual disability were deemed suitable for inclusion. Of these, seven were quantitative/experimental designs (Campbell & McCue, ; Chester et al., , ; Fitzgerald et al., ; Hogue et al., ; Morris et al., ; Novaco & Taylor, ), five were qualitative (Duperouzel & Fish, ; Lovell et al., ; Malda‐Castillo et al., ; Wright et al., ; Wood et al., ), four cohort studies (Russell et al., ; Lindsay, Steptoe, et al., ; Lindsay, Carson, et al., ; Lindsay et al., ), There were two service evaluations/audits (Alexander et al., ; Plant et al., ), two survey designs (Fish et al., ; Mason et al., ), one case study (Ashworth et al., ) and one study utilising the Delphi approach (Morrissey et al., ). 4.2 Findings on risk Three themes each with several sub‐themes related to risk emerged from the analysis of included studies; (1) Forensic risk, (2) Health and wellbeing risk and (3) Risk management. 4.3 Theme 1: Forensic risk In forensic inpatient settings, the most commonly assessed behaviours are risk of violence, risk of sexual offences towards staff, and risk of substance misuse. 4.3.1 Subtheme 1.1: Risk of violence Four studies reported the risk of violence. Chester et al. ( ) compared the characteristics of 401 long‐stay forensic patients in England, including 66 with intellectual disabilities, and 335 without. Chester et al. ( ) reported a higher number of patients with an intellectual disability were involved in serious physical assaults on staff and other patients in forensic settings: 47% compared to 21.5% of the non‐intellectual disability population. However, Malda‐Castillo et al.'s ( ) analysis of routinely collected information and incident reports found a higher rate; reporting that up to 70% of forensic inpatients had been involved in at least one violent incident over 12 months ( n = 138). Physical assaults were the most frequent type of incident with 779 incidences reported over 1 year. There were also a total of 39 sexual assaults directed towards staff reported. This suggests that sexual assault also poses something of a risk to staff, although incidences of physical violence are significantly more common (Malda‐Castillo et al., ). Physical assault, verbal abuse, harassment and psychological abuse were more likely to occur in shared spaces such as lounges, dining rooms and corridors. The authors conclude that staff working in intellectual disability secure services might have an increased risk for client‐inflicted injuries than staff working in non‐intellectual disability inpatient wards. Physical violence leads to longer periods of detention for patients, increases the risk of both harm to and burnout among staff, and increases distress among patients (Novaco & Taylor, ). Malda‐Castillo et al. ( ) argue that, given the potentially severe impact of physical aggression, there remains a lack of knowledge of how violence develops and how intellectual disability services respond to violence. Wright et al. ( ) conducted interviews with patients ( n = 8) and nursing staff ( n = 10) to explore their attitudes towards violence and aggression in a high‐security setting, as a medium for comparing views on ways to prevent violent behaviour. They noted that an ‘institutionalised’ physical environment exacerbates the risk of aggressive behaviour. Gender was seen to be a factor, with male patients suggesting that female nursing staff had a positive impact in reducing aggression, acting as a “calming influence” and spending more time with patients. Than their male counterparts. The authors conclude by arguing that patient involvement in risk management may be one way to minimise the risk of violence in forensic settings. 4.3.2 Subtheme 1.2: Risk of substance misuse Two papers were found concerning historical substance misuse among people with intellectual disabilities in the CJS. Alcohol‐related crime and history of alcohol use were recorded from 477 participants referred to U.K. forensic intellectual disability services (Lindsay, Carson, et al., ). They found 20.8% of inpatients had a history of alcohol misuse and 5.9% had committed an alcohol‐related crime, highlighting alcohol as a significant risk factor. Historical alcohol use may act as a precursor to psychiatric problems in adulthood and is associated with behavioural disturbances including physical aggression, sexual offences, theft and property damage (Lindsay, Carson, et al., ). Investigating substance misuse, Plant et al. ( ) conducted a retrospective baseline audit of case notes from an inpatient forensic service of 74 people with intellectual disabilities (54 males and 20 females) in the east of England. Results showed a significant number of patients ( n = 34, 47%) had a history of harmful use or dependence on alcohol or illegal drugs, with alcohol (41%) and cannabis (28%) being the most commonly used. 4.4 Theme 2: Health and wellbeing risk The review also found literature concerning the mental and physical health and wellbeing risks faced by individuals with intellectual disabilities due to residing in a forensic inpatient setting. 4.4.1 Subtheme 2.1: Physical health risks Two studies reported physical health risks. Russell et al. ( ) examined the weight and body mass index (BMI) data of 46 inpatients (15 women and 31 men) on and during admission to a specialist forensic service. Only six (13%) inpatients were normal weight at admission, whereas 40 (87%) were overweight or obese. During admission, 28 (61%) gained weight. However, 17 (37%) lost weight, although many of this group remained overweight/obese. The authors suggest that the high rates of obesity among this population may be linked to limited opportunities for exercise in forensic settings. Research by Chester et al. ( ) investigated vitamin D deficiency in inpatient forensic intellectual disability services ( n = 84), measuring 25 hydroxy‐vitamin D (25[OHD]) concentrations within the blood. At baseline, 87% of patients were deficient or insufficient, while 13% were sufficient or optimal. At six‐month follow‐up, following supplement treatment, 53% had sufficient or optimal levels. However, some patients remained deficient (13%) or insufficient (34%). The authors identified several risk factors for vitamin D deficiency among this population, which included being non‐ambulatory, poor dietary intake and having limited access to the outside, and consequently, poor sunlight exposure. 4.4.2 Subtheme 2.2: Mental health risk Five studies reported risks to mental health that seemed to stem from behaviours such as violence, self‐injury and self‐neglect. Chester et al. ( ) reported that significantly higher rates of self‐injury were recorded among forensic inpatients with an intellectual disability (77.3%) than the non‐intellectual disability population (61.2%). It should, however, be noted that no significant difference in levels of suicidal behaviour between the two populations was found. Forensic patients with a history of self‐injury reported believing that patients had a higher risk of self‐injury when placed under restrictive measures, with limited movement and privacy. Three qualitative studies reported that feelings of restriction and loss of freedom were associated with increased risk of harm to one's self and others (Wright et al., ) (Duperouzel & Fish, ). Wood et al. ( ) offer specific examples of small restrictions that were linked to individuals experiencing negative emotions including anxiety, anger and dejection. Restrictions could include being unable to decide when to turn lights on/off, deciding when to have a hot drink, deciding when to go out and managing personal finances. 4.5 Theme 3: Risk management Seven papers related to staff nurses and patient views on risk assessment and risk management processes within intellectual disability forensic services. Lovell et al. ( ) explored nurses' perceptions of competencies for working with patients with an intellectual disability. Decision‐making around risk was viewed as integral to the nursing role. Balancing risk was an issue encountered daily and was a source of tension, with nurses fearing the consequences arising from making incorrect decisions regarding patient risks management. Nurses were anxious about and sometimes avoidant of risk, there was ambivalence around testing new therapeutic interventions with individual patients due to fear of negative consequences for the patient in the event something went wrong. One example given was the decision to allow patients to leave the ward alone. While this may be positive for the individual's independence, nurses reported concern about whether a patients' mental state could pose a risk to themselves or others while out in the community. Team decision‐making was viewed as a key part of risk management as it was a way of insuring against repercussions in the case of adverse events arising from an incorrect decision. (Lovell et al., ). The perceived focus on the ‘high consequence/low frequency’ end of the risk spectrum in forensic settings was explored by Higgins et al. ( ) who reported patients were concerned that restrictive measures implemented as part of risk management might, in themselves, pose a risk as they could hinder recovery. Those with moderate intellectual disability who self‐injured reported secure settings lead to a restricted life, with little opportunity to manage day‐to‐day stresses (Duperouzel & Fish, ). In a follow‐up study, Fish et al. ( ) surveyed staff views on the introduction of a harm minimisation risk management policy in a forensic service in England. The authors argue that hoping for the cessation of harm in patients who self‐injure repetitively might be an unrealistic aim because self‐injuring is often a way of coping or surviving distress. 85% of staff in the survey ( n = 71) supported the introduction of a harm minimisation policy that taught patients about wound care, and 72% supported involving patients in care planning and risk management. Finally, Morris et al. ( ) compared the feasibility of two approaches to co‐production (MDT assisted and non‐assisted) in the completion of risk assessments and management plans in a medium secure setting ( n = 54 patients). Patients were invited to review their risk assessments and risk management plans. Thirty‐five (65%) participants rated their risk assessments and 25 (47%) completed risk management plans. Participants who rated their risk assessments separately from the MDT were significantly more likely to complete the risk management plans. This demonstrates that service users are willing to be involved in this key area of care planning. 

Study characteristics Twenty‐two peer‐reviewed articles around issues of risk in U.K. inpatient forensic settings for people with an intellectual disability were deemed suitable for inclusion. Of these, seven were quantitative/experimental designs (Campbell & McCue, ; Chester et al., , ; Fitzgerald et al., ; Hogue et al., ; Morris et al., ; Novaco & Taylor, ), five were qualitative (Duperouzel & Fish, ; Lovell et al., ; Malda‐Castillo et al., ; Wright et al., ; Wood et al., ), four cohort studies (Russell et al., ; Lindsay, Steptoe, et al., ; Lindsay, Carson, et al., ; Lindsay et al., ), There were two service evaluations/audits (Alexander et al., ; Plant et al., ), two survey designs (Fish et al., ; Mason et al., ), one case study (Ashworth et al., ) and one study utilising the Delphi approach (Morrissey et al., ). 

Findings on risk Three themes each with several sub‐themes related to risk emerged from the analysis of included studies; (1) Forensic risk, (2) Health and wellbeing risk and (3) Risk management. 

Theme 1: Forensic risk In forensic inpatient settings, the most commonly assessed behaviours are risk of violence, risk of sexual offences towards staff, and risk of substance misuse. 4.3.1 Subtheme 1.1: Risk of violence Four studies reported the risk of violence. Chester et al. ( ) compared the characteristics of 401 long‐stay forensic patients in England, including 66 with intellectual disabilities, and 335 without. Chester et al. ( ) reported a higher number of patients with an intellectual disability were involved in serious physical assaults on staff and other patients in forensic settings: 47% compared to 21.5% of the non‐intellectual disability population. However, Malda‐Castillo et al.'s ( ) analysis of routinely collected information and incident reports found a higher rate; reporting that up to 70% of forensic inpatients had been involved in at least one violent incident over 12 months ( n = 138). Physical assaults were the most frequent type of incident with 779 incidences reported over 1 year. There were also a total of 39 sexual assaults directed towards staff reported. This suggests that sexual assault also poses something of a risk to staff, although incidences of physical violence are significantly more common (Malda‐Castillo et al., ). Physical assault, verbal abuse, harassment and psychological abuse were more likely to occur in shared spaces such as lounges, dining rooms and corridors. The authors conclude that staff working in intellectual disability secure services might have an increased risk for client‐inflicted injuries than staff working in non‐intellectual disability inpatient wards. Physical violence leads to longer periods of detention for patients, increases the risk of both harm to and burnout among staff, and increases distress among patients (Novaco & Taylor, ). Malda‐Castillo et al. ( ) argue that, given the potentially severe impact of physical aggression, there remains a lack of knowledge of how violence develops and how intellectual disability services respond to violence. Wright et al. ( ) conducted interviews with patients ( n = 8) and nursing staff ( n = 10) to explore their attitudes towards violence and aggression in a high‐security setting, as a medium for comparing views on ways to prevent violent behaviour. They noted that an ‘institutionalised’ physical environment exacerbates the risk of aggressive behaviour. Gender was seen to be a factor, with male patients suggesting that female nursing staff had a positive impact in reducing aggression, acting as a “calming influence” and spending more time with patients. Than their male counterparts. The authors conclude by arguing that patient involvement in risk management may be one way to minimise the risk of violence in forensic settings. 4.3.2 Subtheme 1.2: Risk of substance misuse Two papers were found concerning historical substance misuse among people with intellectual disabilities in the CJS. Alcohol‐related crime and history of alcohol use were recorded from 477 participants referred to U.K. forensic intellectual disability services (Lindsay, Carson, et al., ). They found 20.8% of inpatients had a history of alcohol misuse and 5.9% had committed an alcohol‐related crime, highlighting alcohol as a significant risk factor. Historical alcohol use may act as a precursor to psychiatric problems in adulthood and is associated with behavioural disturbances including physical aggression, sexual offences, theft and property damage (Lindsay, Carson, et al., ). Investigating substance misuse, Plant et al. ( ) conducted a retrospective baseline audit of case notes from an inpatient forensic service of 74 people with intellectual disabilities (54 males and 20 females) in the east of England. Results showed a significant number of patients ( n = 34, 47%) had a history of harmful use or dependence on alcohol or illegal drugs, with alcohol (41%) and cannabis (28%) being the most commonly used. 

Subtheme 1.1: Risk of violence Four studies reported the risk of violence. Chester et al. ( ) compared the characteristics of 401 long‐stay forensic patients in England, including 66 with intellectual disabilities, and 335 without. Chester et al. ( ) reported a higher number of patients with an intellectual disability were involved in serious physical assaults on staff and other patients in forensic settings: 47% compared to 21.5% of the non‐intellectual disability population. However, Malda‐Castillo et al.'s ( ) analysis of routinely collected information and incident reports found a higher rate; reporting that up to 70% of forensic inpatients had been involved in at least one violent incident over 12 months ( n = 138). Physical assaults were the most frequent type of incident with 779 incidences reported over 1 year. There were also a total of 39 sexual assaults directed towards staff reported. This suggests that sexual assault also poses something of a risk to staff, although incidences of physical violence are significantly more common (Malda‐Castillo et al., ). Physical assault, verbal abuse, harassment and psychological abuse were more likely to occur in shared spaces such as lounges, dining rooms and corridors. The authors conclude that staff working in intellectual disability secure services might have an increased risk for client‐inflicted injuries than staff working in non‐intellectual disability inpatient wards. Physical violence leads to longer periods of detention for patients, increases the risk of both harm to and burnout among staff, and increases distress among patients (Novaco & Taylor, ). Malda‐Castillo et al. ( ) argue that, given the potentially severe impact of physical aggression, there remains a lack of knowledge of how violence develops and how intellectual disability services respond to violence. Wright et al. ( ) conducted interviews with patients ( n = 8) and nursing staff ( n = 10) to explore their attitudes towards violence and aggression in a high‐security setting, as a medium for comparing views on ways to prevent violent behaviour. They noted that an ‘institutionalised’ physical environment exacerbates the risk of aggressive behaviour. Gender was seen to be a factor, with male patients suggesting that female nursing staff had a positive impact in reducing aggression, acting as a “calming influence” and spending more time with patients. Than their male counterparts. The authors conclude by arguing that patient involvement in risk management may be one way to minimise the risk of violence in forensic settings. 

Subtheme 1.2: Risk of substance misuse Two papers were found concerning historical substance misuse among people with intellectual disabilities in the CJS. Alcohol‐related crime and history of alcohol use were recorded from 477 participants referred to U.K. forensic intellectual disability services (Lindsay, Carson, et al., ). They found 20.8% of inpatients had a history of alcohol misuse and 5.9% had committed an alcohol‐related crime, highlighting alcohol as a significant risk factor. Historical alcohol use may act as a precursor to psychiatric problems in adulthood and is associated with behavioural disturbances including physical aggression, sexual offences, theft and property damage (Lindsay, Carson, et al., ). Investigating substance misuse, Plant et al. ( ) conducted a retrospective baseline audit of case notes from an inpatient forensic service of 74 people with intellectual disabilities (54 males and 20 females) in the east of England. Results showed a significant number of patients ( n = 34, 47%) had a history of harmful use or dependence on alcohol or illegal drugs, with alcohol (41%) and cannabis (28%) being the most commonly used. 

Theme 2: Health and wellbeing risk The review also found literature concerning the mental and physical health and wellbeing risks faced by individuals with intellectual disabilities due to residing in a forensic inpatient setting. 4.4.1 Subtheme 2.1: Physical health risks Two studies reported physical health risks. Russell et al. ( ) examined the weight and body mass index (BMI) data of 46 inpatients (15 women and 31 men) on and during admission to a specialist forensic service. Only six (13%) inpatients were normal weight at admission, whereas 40 (87%) were overweight or obese. During admission, 28 (61%) gained weight. However, 17 (37%) lost weight, although many of this group remained overweight/obese. The authors suggest that the high rates of obesity among this population may be linked to limited opportunities for exercise in forensic settings. Research by Chester et al. ( ) investigated vitamin D deficiency in inpatient forensic intellectual disability services ( n = 84), measuring 25 hydroxy‐vitamin D (25[OHD]) concentrations within the blood. At baseline, 87% of patients were deficient or insufficient, while 13% were sufficient or optimal. At six‐month follow‐up, following supplement treatment, 53% had sufficient or optimal levels. However, some patients remained deficient (13%) or insufficient (34%). The authors identified several risk factors for vitamin D deficiency among this population, which included being non‐ambulatory, poor dietary intake and having limited access to the outside, and consequently, poor sunlight exposure. 4.4.2 Subtheme 2.2: Mental health risk Five studies reported risks to mental health that seemed to stem from behaviours such as violence, self‐injury and self‐neglect. Chester et al. ( ) reported that significantly higher rates of self‐injury were recorded among forensic inpatients with an intellectual disability (77.3%) than the non‐intellectual disability population (61.2%). It should, however, be noted that no significant difference in levels of suicidal behaviour between the two populations was found. Forensic patients with a history of self‐injury reported believing that patients had a higher risk of self‐injury when placed under restrictive measures, with limited movement and privacy. Three qualitative studies reported that feelings of restriction and loss of freedom were associated with increased risk of harm to one's self and others (Wright et al., ) (Duperouzel & Fish, ). Wood et al. ( ) offer specific examples of small restrictions that were linked to individuals experiencing negative emotions including anxiety, anger and dejection. Restrictions could include being unable to decide when to turn lights on/off, deciding when to have a hot drink, deciding when to go out and managing personal finances. 

Subtheme 2.1: Physical health risks Two studies reported physical health risks. Russell et al. ( ) examined the weight and body mass index (BMI) data of 46 inpatients (15 women and 31 men) on and during admission to a specialist forensic service. Only six (13%) inpatients were normal weight at admission, whereas 40 (87%) were overweight or obese. During admission, 28 (61%) gained weight. However, 17 (37%) lost weight, although many of this group remained overweight/obese. The authors suggest that the high rates of obesity among this population may be linked to limited opportunities for exercise in forensic settings. Research by Chester et al. ( ) investigated vitamin D deficiency in inpatient forensic intellectual disability services ( n = 84), measuring 25 hydroxy‐vitamin D (25[OHD]) concentrations within the blood. At baseline, 87% of patients were deficient or insufficient, while 13% were sufficient or optimal. At six‐month follow‐up, following supplement treatment, 53% had sufficient or optimal levels. However, some patients remained deficient (13%) or insufficient (34%). The authors identified several risk factors for vitamin D deficiency among this population, which included being non‐ambulatory, poor dietary intake and having limited access to the outside, and consequently, poor sunlight exposure. 

Subtheme 2.2: Mental health risk Five studies reported risks to mental health that seemed to stem from behaviours such as violence, self‐injury and self‐neglect. Chester et al. ( ) reported that significantly higher rates of self‐injury were recorded among forensic inpatients with an intellectual disability (77.3%) than the non‐intellectual disability population (61.2%). It should, however, be noted that no significant difference in levels of suicidal behaviour between the two populations was found. Forensic patients with a history of self‐injury reported believing that patients had a higher risk of self‐injury when placed under restrictive measures, with limited movement and privacy. Three qualitative studies reported that feelings of restriction and loss of freedom were associated with increased risk of harm to one's self and others (Wright et al., ) (Duperouzel & Fish, ). Wood et al. ( ) offer specific examples of small restrictions that were linked to individuals experiencing negative emotions including anxiety, anger and dejection. Restrictions could include being unable to decide when to turn lights on/off, deciding when to have a hot drink, deciding when to go out and managing personal finances. 

Theme 3: Risk management Seven papers related to staff nurses and patient views on risk assessment and risk management processes within intellectual disability forensic services. Lovell et al. ( ) explored nurses' perceptions of competencies for working with patients with an intellectual disability. Decision‐making around risk was viewed as integral to the nursing role. Balancing risk was an issue encountered daily and was a source of tension, with nurses fearing the consequences arising from making incorrect decisions regarding patient risks management. Nurses were anxious about and sometimes avoidant of risk, there was ambivalence around testing new therapeutic interventions with individual patients due to fear of negative consequences for the patient in the event something went wrong. One example given was the decision to allow patients to leave the ward alone. While this may be positive for the individual's independence, nurses reported concern about whether a patients' mental state could pose a risk to themselves or others while out in the community. Team decision‐making was viewed as a key part of risk management as it was a way of insuring against repercussions in the case of adverse events arising from an incorrect decision. (Lovell et al., ). The perceived focus on the ‘high consequence/low frequency’ end of the risk spectrum in forensic settings was explored by Higgins et al. ( ) who reported patients were concerned that restrictive measures implemented as part of risk management might, in themselves, pose a risk as they could hinder recovery. Those with moderate intellectual disability who self‐injured reported secure settings lead to a restricted life, with little opportunity to manage day‐to‐day stresses (Duperouzel & Fish, ). In a follow‐up study, Fish et al. ( ) surveyed staff views on the introduction of a harm minimisation risk management policy in a forensic service in England. The authors argue that hoping for the cessation of harm in patients who self‐injure repetitively might be an unrealistic aim because self‐injuring is often a way of coping or surviving distress. 85% of staff in the survey ( n = 71) supported the introduction of a harm minimisation policy that taught patients about wound care, and 72% supported involving patients in care planning and risk management. Finally, Morris et al. ( ) compared the feasibility of two approaches to co‐production (MDT assisted and non‐assisted) in the completion of risk assessments and management plans in a medium secure setting ( n = 54 patients). Patients were invited to review their risk assessments and risk management plans. Thirty‐five (65%) participants rated their risk assessments and 25 (47%) completed risk management plans. Participants who rated their risk assessments separately from the MDT were significantly more likely to complete the risk management plans. This demonstrates that service users are willing to be involved in this key area of care planning. 

DISCUSSION 5.1 Discussion of principal findings This review was undertaken to map and appraise the current evidence base around risk in relation to people with an intellectual disability in forensic settings. It is important to highlight that the discussion of findings pertains specifically to studies conducted in the United Kingdom. A distinction was drawn between forensic risks (risks that have a legal or criminal justice element) and health and wellbeing risks (relating to the patient's physical and mental health). The results of the review show that forensic risk and patterns of offending among inpatients with an intellectual disability have received greater attention in the literature than aspects of health and wellbeing. The academic evidence suggests that the risk of violence is a primary concern in UK forensic inpatient settings. Evidence was also found to suggest that a history of substance misuse could be a risk factor for aggressive behaviours and sexually inappropriate behaviour. The focus on the risk of violence is unsurprising given the significant body of work testing the efficacy of risk assessment tools with forensic inpatients with intellectual disabilities. Examples of these tools include the Historical Clinical Risk Management‐20, Version 3 (Douglas et al., ) and Risk for Sexual Violence Protocol (RSVP) (Hart & Boer, ). with inpatients with an intellectual disability. The strength of the evidence base pertaining to the efficacy of risk assessment tools may indicate a focus on the ‘high consequence/low frequency’ aspects of risk (Higgins et al., ): professionals focusing on mitigating the risk of serious but infrequent events (violence, inappropriate sexual behaviour) over less noticeable long term risks (Obesity, vitamin D deficiency). A notable finding was the evidence regarding risks posed to physical health by long term residency in a forensic setting, with just two studies found highlighting the increased risk of vitamin D deficiency, obesity and diabetes which could negatively impact long‐term health outcomes for people with an intellectual disability. Although concerns have been expressed about the suitability of forensic environments for inpatients with intellectual disabilities (Mental Welfare Commission, ), the review findings show a paucity of evidence in this area. Some qualitative evidence suggested that a perceived lack of control and overly restrictive measures were a factor in higher rates of depression, anxiety, and increased risk of self‐injury in U.K. forensic inpatient settings. Interviews conducted with non‐intellectually disabled forensic inpatients in England ( n = 18) reported feelings of boredom, humiliation, and anger among those experiencing restrictions, but did not find evidence of the anxious and depressive symptomology reported by patients with an intellectual disability (Tomlin et al., ). This seems to indicate that if measures to reduce forensic risk are introduced, there may be negative consequences for the health and wellbeing of people with intellectual disabilities. Learning disability nurses reported difficulty in balancing the cost/benefit of risks, often relying on a multidisciplinary team approach to decision making around risk to minimise the impact of adverse events on inpatients with an intellectual disability. Multidisciplinary approaches to risk management are common in other CJS settings including community settings, with non‐intellectually disabled forensic inpatients (Haines et al., ) and internationally (Orovwuje, ). Haines et al. ( ) reported that MDT decision making around forensic risk is shaped by the values, knowledge, and power dynamics within MDT, with the views of service users often being side‐lined. There as one paper on the topic of using coproduction to enable patient input on issues of risk, and whether this is effective in improving the management of risk and care provided for people with intellectual disabilities in UK forensic settings (Morris et al., ). When given the opportunity, the majority of patients with an intellectual disability actively engaged in risk assessments and the drafting of risk management plans, indicating a willingness among patients to discuss risk and the potential value of coproduction in facilitating this. This small evidence base aligns with wider research regarding the involvement of people with intellectual disabilities in care planning in health services. A recent review found that the experiences of adults with intellectual disability involvement in care planning within health services are mostly absent within literature, with existing guidance using ambiguous and confusing language (Doody et al., ). Given the communication challenges people with an intellectual disability can face, including issues learning new information, remembering and processing, problem‐solving and developing coping strategies for novel situations (Drainoni et al., ) this avenue of research may benefit from further exploration. 5.2 Strengths and weaknesses of the review Despite the overrepresentation of people with an intellectual disability in the forensic population, no previous reviews have appraised and synthesised evidence around issues of risk for forensic inpatients with an intellectual disability. The search strategy for the review was extensive and included multiple databases, screening reference lists and freehand searching. The research team had input from forensic nursing, medical, and allied health professional staff to refine the terminology within the search strategy. Due to time limitations, there were constraints to the search strategy. Only papers in the English language and published since 2000 were included. However, the research team felt this was justified given that research with the intellectually disabled forensic population started to receive major attention in the late 1990s. While relevant grey literature was retained, it was not formally included and did not form part of the results and discussion of the review. Hence, some pertinent information may have been missed due to the exclusion of grey literature. The diversity of study designs and populations also made it challenging to compare results and synthesise some findings. In addition, the review focused on the United Kingdom as its geographical setting so that other countries and regions of the world are missing, meaning the results should be interpreted with caution. 5.3 Recommendations for education, policy, practice and research This review has identified several knowledge gaps and recommendations are made for future research. There is some evidence to suggest that inpatients with intellectual disabilities in forensic settings face significant health risks, including a higher chance of developing obesity, diabetes, and vitamin D deficiency. There is a range of research within the general CJS population, concerning the efficacy of interventions to improve health outcomes (South et al., ) Therefore, further research is required regarding the appropriateness and effectiveness of these interventions for forensic inpatients with intellectual disabilities. The risk of violence and inappropriate sexual behaviour within this population is somewhat established in current literature, and robust violence and sexual behaviour risk assessment tools exist, although management strategies to address these need further attention. The apparent increased risk to health and wellbeing if overly restrictive measures are put in place in forensic settings needs further exploration so that assessment and management are proportionate to the level of risk, and considers the impact on individual health and wellbeing alongside forensic risk. While the rights of patients to direct their care planning and risk management are enshrined in some U.K. health policies, and evidence suggests that staff support the inclusion of forensic patients with intellectual disabilities in their risk management, further research is required to establish the effectiveness of interventions for facilitating patient‐led discussions about risk in forensic settings – coproduction methods have shown some promise in this area. Additional work is also required to assess the extent to which patient involvement in risk management helps to mitigate future risks, and if patient input into risk management can lead to a reduction in restrictive measures. 

Discussion of principal findings This review was undertaken to map and appraise the current evidence base around risk in relation to people with an intellectual disability in forensic settings. It is important to highlight that the discussion of findings pertains specifically to studies conducted in the United Kingdom. A distinction was drawn between forensic risks (risks that have a legal or criminal justice element) and health and wellbeing risks (relating to the patient's physical and mental health). The results of the review show that forensic risk and patterns of offending among inpatients with an intellectual disability have received greater attention in the literature than aspects of health and wellbeing. The academic evidence suggests that the risk of violence is a primary concern in UK forensic inpatient settings. Evidence was also found to suggest that a history of substance misuse could be a risk factor for aggressive behaviours and sexually inappropriate behaviour. The focus on the risk of violence is unsurprising given the significant body of work testing the efficacy of risk assessment tools with forensic inpatients with intellectual disabilities. Examples of these tools include the Historical Clinical Risk Management‐20, Version 3 (Douglas et al., ) and Risk for Sexual Violence Protocol (RSVP) (Hart & Boer, ). with inpatients with an intellectual disability. The strength of the evidence base pertaining to the efficacy of risk assessment tools may indicate a focus on the ‘high consequence/low frequency’ aspects of risk (Higgins et al., ): professionals focusing on mitigating the risk of serious but infrequent events (violence, inappropriate sexual behaviour) over less noticeable long term risks (Obesity, vitamin D deficiency). A notable finding was the evidence regarding risks posed to physical health by long term residency in a forensic setting, with just two studies found highlighting the increased risk of vitamin D deficiency, obesity and diabetes which could negatively impact long‐term health outcomes for people with an intellectual disability. Although concerns have been expressed about the suitability of forensic environments for inpatients with intellectual disabilities (Mental Welfare Commission, ), the review findings show a paucity of evidence in this area. Some qualitative evidence suggested that a perceived lack of control and overly restrictive measures were a factor in higher rates of depression, anxiety, and increased risk of self‐injury in U.K. forensic inpatient settings. Interviews conducted with non‐intellectually disabled forensic inpatients in England ( n = 18) reported feelings of boredom, humiliation, and anger among those experiencing restrictions, but did not find evidence of the anxious and depressive symptomology reported by patients with an intellectual disability (Tomlin et al., ). This seems to indicate that if measures to reduce forensic risk are introduced, there may be negative consequences for the health and wellbeing of people with intellectual disabilities. Learning disability nurses reported difficulty in balancing the cost/benefit of risks, often relying on a multidisciplinary team approach to decision making around risk to minimise the impact of adverse events on inpatients with an intellectual disability. Multidisciplinary approaches to risk management are common in other CJS settings including community settings, with non‐intellectually disabled forensic inpatients (Haines et al., ) and internationally (Orovwuje, ). Haines et al. ( ) reported that MDT decision making around forensic risk is shaped by the values, knowledge, and power dynamics within MDT, with the views of service users often being side‐lined. There as one paper on the topic of using coproduction to enable patient input on issues of risk, and whether this is effective in improving the management of risk and care provided for people with intellectual disabilities in UK forensic settings (Morris et al., ). When given the opportunity, the majority of patients with an intellectual disability actively engaged in risk assessments and the drafting of risk management plans, indicating a willingness among patients to discuss risk and the potential value of coproduction in facilitating this. This small evidence base aligns with wider research regarding the involvement of people with intellectual disabilities in care planning in health services. A recent review found that the experiences of adults with intellectual disability involvement in care planning within health services are mostly absent within literature, with existing guidance using ambiguous and confusing language (Doody et al., ). Given the communication challenges people with an intellectual disability can face, including issues learning new information, remembering and processing, problem‐solving and developing coping strategies for novel situations (Drainoni et al., ) this avenue of research may benefit from further exploration. 

Strengths and weaknesses of the review Despite the overrepresentation of people with an intellectual disability in the forensic population, no previous reviews have appraised and synthesised evidence around issues of risk for forensic inpatients with an intellectual disability. The search strategy for the review was extensive and included multiple databases, screening reference lists and freehand searching. The research team had input from forensic nursing, medical, and allied health professional staff to refine the terminology within the search strategy. Due to time limitations, there were constraints to the search strategy. Only papers in the English language and published since 2000 were included. However, the research team felt this was justified given that research with the intellectually disabled forensic population started to receive major attention in the late 1990s. While relevant grey literature was retained, it was not formally included and did not form part of the results and discussion of the review. Hence, some pertinent information may have been missed due to the exclusion of grey literature. The diversity of study designs and populations also made it challenging to compare results and synthesise some findings. In addition, the review focused on the United Kingdom as its geographical setting so that other countries and regions of the world are missing, meaning the results should be interpreted with caution. 

Recommendations for education, policy, practice and research This review has identified several knowledge gaps and recommendations are made for future research. There is some evidence to suggest that inpatients with intellectual disabilities in forensic settings face significant health risks, including a higher chance of developing obesity, diabetes, and vitamin D deficiency. There is a range of research within the general CJS population, concerning the efficacy of interventions to improve health outcomes (South et al., ) Therefore, further research is required regarding the appropriateness and effectiveness of these interventions for forensic inpatients with intellectual disabilities. The risk of violence and inappropriate sexual behaviour within this population is somewhat established in current literature, and robust violence and sexual behaviour risk assessment tools exist, although management strategies to address these need further attention. The apparent increased risk to health and wellbeing if overly restrictive measures are put in place in forensic settings needs further exploration so that assessment and management are proportionate to the level of risk, and considers the impact on individual health and wellbeing alongside forensic risk. While the rights of patients to direct their care planning and risk management are enshrined in some U.K. health policies, and evidence suggests that staff support the inclusion of forensic patients with intellectual disabilities in their risk management, further research is required to establish the effectiveness of interventions for facilitating patient‐led discussions about risk in forensic settings – coproduction methods have shown some promise in this area. Additional work is also required to assess the extent to which patient involvement in risk management helps to mitigate future risks, and if patient input into risk management can lead to a reduction in restrictive measures. 

CONCLUSION Risk is a broad and dynamic concept encompassing health, wellbeing and forensic risk. This review of risk associated with U.K. forensic inpatient settings found that individuals with an intellectual disability are at higher risk of violence, sexually risky behaviour, and self‐injury. The evidence base around health risks indicated an increased likelihood of experiencing mental health issues, sensory problems, and obesity compared to the general CJS population. Analysis of nurses' perceptions of risk assessment and management showed that balancing risks and managing patient and staff safety is a source of tension encountered daily. Furthermore, patients reported that restrictive measures and lack of freedom were significant factors in exacerbating certain mental health and wellbeing risks such as anxiety. 

The authors declare no conflict of interest. 

