GMH and specialist intellectual disability in-patient service models of care for adults

The studies identified referred to two broad approaches to in-patient mental health for adults with intellectual disabilities and/or and autism: (a) admission to in-patient general psychiatric or mental health services (with other patients who do not have intellectual disabilities and/or autism)^{Reference Lohrer, Greene, Browning and Lesser68} or (b) admission to in-patient specialist services designed for those with intellectual disabilities and/or autism.^{Reference Trower, Treadwell and Bhaumik3}

For adults with intellectual disabilities and/or autism in GMH in-patient services, it was noted that admission could be to GMH beds^{Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference Schmitz-Buhl, Gairing, Rietz, Haussermann, Zielasek and Gouzoulis-Mayfrank69} or ‘specialist intellectual disability beds’ located within an otherwise GMH service.^{Reference Singh, Khalid and Dickinson2,Reference Alexander, Piachaud and Singh5,Reference Hall, Parkes, Samuels and Hassiotis8} Specialist beds within GMH services were typically described as a separate ward or unit,^{Reference Alexander, Piachaud and Singh5} with a few authors reporting that staff within these services had specialist knowledge of intellectual disabilities or treatment and therapeutic programmes adapted for this group.^{Reference Hall, Parkes, Samuels and Hassiotis8,Reference Lunsky, Bradley, Durbin and Koegl70} Specialist intellectual disability services or units tended to be smaller, with reports of 6- or 14-bed units,^{Reference Hurst, Nadarajah and Cumella1,Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7} compared with GMH services.^{Reference Van Melle, Noorthoorn, Widdershoven, Mulder and Voskes71} It was noted that ‘specialist’ in this context was not clearly defined, but included reference to the training of staff and the adaptation of interventions to meet the needs of in-patients.

Both the GMH and specialist intellectual disability in-patient service models for adults were characterised by 24-h care and a ‘locked’ environment, although some patients were described as having free ‘access’ to the community, depending on the nature of their admission or detention status.^{Reference Alexander, Piachaud and Singh5,Reference Seager, Bell and O'Brien72} Patients had access to psychiatry and nursing care, and frequently, a multidisciplinary team including nursing, psychologists and allied health professions, such as speech and language therapy and occupational therapy.^{Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73}

Therapeutic and treatment services offered in GMH and specialist in-patient intellectual disability services included group and individual psychotherapy, medication, and behavioural and educational programmes. Further details regarding treatment components specifically for patients with intellectual disabilities were sparse, but were described more so within papers about specialist in-patient intellectual disability services rather than GMH in-patient services, and included staffing levels,^{Reference Bakken and Hoidat74} staff training programmes or requirements,^{Reference Hurst, Nadarajah and Cumella1,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14} ratio of different types of nurses (those with training in intellectual disabilities versus mental health),^{Reference Hurst, Nadarajah and Cumella1,Reference Trower, Treadwell and Bhaumik3,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73} patient/staff ratios^{Reference Raitasuo, Taiminen and Salokangas4} and use/availability of ‘adapted’ treatment or therapeutic programmes.^{Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14} Those that did report such information were frequently pilot studies or retrospective case reviews of new service models; for example, enhanced out-patient services compared with in-patient treatment,^{Reference Richings, Cook and Roy75} or studies on early or new specialist intellectual disability in-patient services.^{Reference Singh, Khalid and Dickinson2,Reference Alexander, Piachaud and Singh5}

Within studies, GMH and specialist intellectual disability in-patient services were described using different language, such as acute assessment and treatment,^{Reference Mackenzie-Davies and Mansell76} or services for ‘longer-stay’ patients.^{Reference Ashaye, Mathew and Dhadphale77} Some authors described the purpose for admission and the expected duration of stay, such as admission for assessment and treatment,^{Reference Sandhu and Tomlins78} or emergency care/admission with short stays.^{Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26}

Details of ‘aftercare’ following discharge, including collaborative working with community services, were absent from much of adult literature. The impact of an enhanced community assessment and treatment team on in-patient admissions was evaluated within one study,^{Reference Richings, Cook and Roy75} although such an approach to evaluation appears to be the exception. Other groups of authors reported a poor availability of community placements that resulted in ‘bed-blocking’ and delayed discharges,^{Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73,Reference Perera, Simpson, Douds and Campbell79} and a single study referred to ‘telepsychiatric’ support for patients ‘discharged’ (resided in family home but still a ‘patient’) during the COVID-19 pandemic.^{Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33}

No autism-specific service treatment models or service/unit types for adults were identified in the review.

Measures of effectiveness

There were 70 studies categorised as investigating measures of effectiveness within GMH and specialist intellectual disability in-patient services.

Length of stay

Thirty-nine studies reported information about length of stay within GMH and/or specialist intellectual disability in-patient services. Thirteen of these studies reported length-of-stay data for adults with intellectual disabilities and/or autism within GMH units only, with no comparison with data from specialist intellectual disability services.^{Reference Singh, Khalid and Dickinson2,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference Di Lorenzo, Olmi, Riolo, Galeazzi and Ferri29,Reference Lunsky, Bradley, Durbin, Koegl, Canrinus and Goering34,Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Lohrer, Greene, Browning and Lesser68,Reference Mackenzie-Davies and Mansell76,Reference Saeed, Ouellette-Kuntz, Stuart and Burge98–Reference Lunsky and Balogh102} Eight of the 13 studies compared length-of-stay data for adults with and without intellectual disabilities and/or autism in GMH services,^{Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference Di Lorenzo, Olmi, Riolo, Galeazzi and Ferri29,Reference Lunsky, Bradley, Durbin, Koegl, Canrinus and Goering34,Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Lohrer, Greene, Browning and Lesser68,Reference Saeed, Ouellette-Kuntz, Stuart and Burge98,Reference Axmon, Bjorne, Nylander and Ahlstrom100,Reference Lunsky and Balogh102} and five reported length-of-stay data for patients with intellectual disabilities and/or autism only.^{Reference Singh, Khalid and Dickinson2,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Mackenzie-Davies and Mansell76,Reference Gustafsson99,Reference Sheehan, Mutch, Marston, Osborn and Hassiotis101} Three of the 13 studies reported medians,^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Saeed, Ouellette-Kuntz, Stuart and Burge98,Reference Axmon, Bjorne, Nylander and Ahlstrom100} with nine reporting the mean. A single study reported a range for length-of-stay data and the mean or median could not be extracted^{Reference Lunsky and Balogh102} The authors of all but two studies^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Lunsky and Balogh102} reported that adults with intellectual disabilities and/or autism had a longer length of stay compared with in-patients without intellectual disabilities and/or autism. The average in-patient stay within GMH in-patient services for those with intellectual disabilities and/or autism ranged from 29.40 days to substantially longer admissions of over 5 years.^{Reference Singh, Khalid and Dickinson2,Reference Lunsky, Bradley, Durbin, Koegl, Canrinus and Goering34} When length of stay was averaged across studies, the mean length of stay for those with intellectual disabilities and/or autism was substantially shorter within GMH in-patient services than the length of stay for those without intellectual disabilities and/or autism (Table 4). However, when in-patients without intellectual disabilities and/or autism who were classed as ‘long stay’ were excluded, the difference in length of stay between those with and without intellectual disabilities and/or autism within GMH in-patient services disappeared (Table 3). Examining the median length of stay as reported within studies^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Saeed, Ouellette-Kuntz, Stuart and Burge98,Reference Axmon, Bjorne, Nylander and Ahlstrom100} also indicated that those with intellectual disabilities and/or autism had a shorter length of stay compared with patients without intellectual disabilities and/or autism within GMH in-patient services (Table 4).^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Perera, Simpson, Douds and Campbell79}

Table 4 Mean and median length of stay for in-patients within general mental health and specialist intellectual disability in-patient services

A further 26 studies reported length-of-stay data for adults with intellectual disabilities and/or autism in specialist in-patient intellectual disability services. Eleven studies explored length of stay within specialist intellectual disabilities services and/or GMH services, and comparisons were made between the two^{Reference Alexander, Piachaud and Singh5,Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7,Reference Glover, Brown and Hatton24,Reference Hemmings, O'Hara, McCarthy, Holt, Eoster and Costello105–Reference Ganguly, Gore, Marston and Roy107} or between those with and without intellectual disabilities.^{Reference Lunsky, Gracey and Bradley55,Reference Ashaye, Mathew and Dhadphale77,Reference Perera, Simpson, Douds and Campbell79,Reference Lunsky and Balogh102,Reference O'Brien and Beasley108} The remaining 15 papers reported data about in-patients with intellectual disability and/or autism in specialist intellectual disability services only (Table 3).^{Reference Hurst, Nadarajah and Cumella1,Reference Trower, Treadwell and Bhaumik3,Reference Raitasuo, Taiminen and Salokangas4,Reference Tajuddin, Nadkarni, Biswas, Watson and Bhaumik6,Reference Hall, Parkes, Samuels and Hassiotis8,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Kokoski and Lunsky35,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73–Reference Richings, Cook and Roy75,Reference Sandhu and Tomlins78,Reference Xenitidis, Henry, Russell, Ward and Murphy104,Reference Palucka, Raina, Liu and Lunksy109–Reference Oxley, Sathanandan, Gazizova, Fitzgerald and Puri111} The mean and the average median length of stay within specialist in-patient intellectual disability services was longer compared with GMH in-patient services, but was shorter when those identified as long stay were removed (Table 4).

There was a single study about the admission of adults with intellectual disabilities and a history of forensic mental health problems to GMH in-patient services,^{Reference Lunsky, Gracey, Koegl, Bradley, Durbin and Raina97} and length of stay was shorter for this group than for adults with intellectual disabilities who did not have forensic mental health problems. It is likely that this was because many were transferred to specialist forensic services following their admission, as there is evidence that forensic mental health needs are associated with discharge to non-community settings.^{Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7}

A diagnosis of autism was associated with a longer length of stay within both GMH and specialist intellectual disability in-patient services.^{Reference Kokoski and Lunsky35,Reference Lunsky, Gracey and Bradley55} The authors of one study reported that those with intellectual disabilities and autism had a longer length of stay than those with intellectual disabilities without co-occurring autism.^{Reference Lunsky, Gracey and Bradley55}

Discharge pathway

Across 24 studies, the percentage of in-patients with intellectual disabilities and/or autism who were discharged to their residence before admission ranged from 40 to 83%,^{Reference Singh, Khalid and Dickinson2–Reference Raitasuo, Taiminen and Salokangas4,Reference Tajuddin, Nadkarni, Biswas, Watson and Bhaumik6,Reference Prichard, Palucka, Reid and Yunsky57,Reference Sheehan, Mutch, Marston, Osborn and Hassiotis101} whereas 27.5–45% were discharged to a different residence/new placement.^{Reference Singh, Khalid and Dickinson2–Reference Raitasuo, Taiminen and Salokangas4,Reference Tajuddin, Nadkarni, Biswas, Watson and Bhaumik6} The authors of a single study reported that discharge to a new location was associated with a longer in-patient admission and difficulties with internalising or externalising behaviours, whereas discharge to the same residence as before admission was associated with living in a socially deprived area.^{Reference Sheehan, Mutch, Marston, Osborn and Hassiotis101} Those discharged from specialist intellectual disability in-patient services were reported as less likely to be from ‘out of area’,^{Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7} and more likely to go back to the family home, than those discharged from GMH in-patient services.^{Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26}

Three studies reported ‘delayed discharge’ rates ranging from 10 to 63% for in-patients with intellectual disabilities.^{Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73,Reference Perera, Simpson, Douds and Campbell79,Reference Oxley, Sathanandan, Gazizova, Fitzgerald and Puri111} However, the authors of a single study reported that in-patients with intellectual disabilities were no more difficult to discharge or more likely to stay beyond their discharge date than in-patients without intellectual disabilities, but were more likely to be discharged to their prior accommodation compared with in-patients without intellectual disabilities within GMH in-patient services.^{Reference Lohrer, Greene, Browning and Lesser68} Discharges from both GMH and specialist intellectual disability in-patient services to the community tended to be high.^{Reference Hurst, Nadarajah and Cumella1,Reference Singh, Khalid and Dickinson2,Reference Xenitidis, Henry, Russell, Ward and Murphy104} For example, Xenitidis et al^{Reference Xenitidis, Henry, Russell, Ward and Murphy104} reported that 84% of all admissions from community settings and 81% of all admissions from non-community settings were discharged to the community. Within the same study, a history of fire setting was noted to be associated with discharge to non-community settings. Within more recent studies, discharges to group homes and shared residential settings rather than to family homes appeared to be more frequent, suggesting changes in the model of community care for this group over time.^{Reference Richings, Cook and Roy75,Reference Hemmings, O'Hara, McCarthy, Holt, Eoster and Costello105,Reference Oxley, Sathanandan, Gazizova, Fitzgerald and Puri111}

In two studies from Canada, higher levels of recommended care were seen as being needed for adults with intellectual disabilities and/or autism compared with those without disabilities, which included considering whether someone could manage in the community themselves, required residential support or continued to require in-patient care.^{Reference Lunsky, Gracey and Bradley55,Reference Lunsky, Bradley, Durbin and Koegl70} Consideration for increasing outreach programmes and more intensive discharge planning for adults with intellectual disabilities were reported as needed.^{Reference Lunsky, Gracey and Bradley55}

Clinical outcomes

Seventeen papers reported outcomes from assessments of mental health, psychiatric symptoms or risk and challenging behaviour.^{Reference Hurst, Nadarajah and Cumella1,Reference Raitasuo, Taiminen and Salokangas4,Reference Tajuddin, Nadkarni, Biswas, Watson and Bhaumik6–Reference Hall, Parkes, Samuels and Hassiotis8,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference Kokoski and Lunsky35,Reference van Minnen, Hoogduin and Broekman36,Reference Davies, Josham and Francis38,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73,Reference Richings, Cook and Roy75,Reference Ashaye, Mathew and Dhadphale77,Reference Sandhu and Tomlins78,Reference Gustafsson and Sonnander103,Reference White, Lunsky and Grieve106,Reference Iversen, Horndalsveen, Matre, Henriksen, Fusche and Kildahl110} A range of clinical assessments were used to measure mental health symptoms and index outcome from treatment during an in-patient stay. Examples of these included the Clinical Global Impression Scale;^{Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference Guy40} assessments of behaviour and functioning, such as the Global Assessment of Functioning Scales,^{Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7,Reference Hall44,Reference White, Lunsky and Grieve106} Aberrant Behaviour Checklist^{Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Aman, Singh, Stewart and Field39} and Reiss Screen for Maladaptive Behaviour;^{Reference Kokoski and Lunsky35,Reference van Minnen, Hoogduin and Broekman36,Reference Reiss140} and measures of overall health outcomes such as the Health of the Nation Outcome Scales (HoNOS), including the version for people with intellectual disabilities.^{Reference Hall, Parkes, Samuels and Hassiotis8,Reference Roy, Matthews, Clifford, Fowler and Martin37}

Admission to in-patient services, either GMH or specialist intellectual disability in-patient services, was associated with improvements in symptoms during the stay,^{Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7,Reference Gowda, Gopika, Kumar, Manjunatha, Yadav and Srinivas26,Reference White, Lunsky and Grieve106} with some demonstrating continued improvements at follow-up.^{Reference Raitasuo, Taiminen and Salokangas4,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14} The authors of a single study reported that admission to a GMH in-patient service was associated with increased clinical symptoms at both admission and discharge, compared with admission to specialist intellectual disability in-patient services.^{Reference White, Lunsky and Grieve106} The author of another paper reported that adults with autism tended to have increased difficulties with adaptive behaviour and functioning when admitted to psychiatric services, compared with those with intellectual disabilities without comorbid autism.^{Reference Kokoski and Lunsky35} van Minnen et al^{Reference van Minnen, Hoogduin and Broekman36} completed a clinical trial where adults with intellectual disabilities were randomised to either in-patient admission or enhanced community-based treatment. Their findings indicated that psychiatric symptoms at the end of the trial did not differ between the two groups, and they argued that enhanced treatment in the community may be appropriate for some people with intellectual disabilities who are experiencing mental health crisis.

A single paper made comparisons between elderly longer-stay patients with and without intellectual disabilities.^{Reference Ashaye, Mathew and Dhadphale77} They reported that elderly in-patients without intellectual disabilities within GMH in-patient services had more problems with relationships, occupation, activities and depressed mood, compared with elderly patients with intellectual disabilities within a specialist intellectual disability in-patient service. The authors suggested that the differences between the groups supported the use of specialist in-patient services for those with intellectual disabilities.

Readmissions

Readmission was considered within 16 papers.^{Reference Hurst, Nadarajah and Cumella1,Reference Trower, Treadwell and Bhaumik3–Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7,Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Seager, Bell and O'Brien72,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73,Reference Sheehan, Mutch, Marston, Osborn and Hassiotis101,Reference Lunsky and Balogh102,Reference Ganguly, Gore, Marston and Roy107,Reference Oxley, Sathanandan, Gazizova, Fitzgerald and Puri111,Reference Lyall and Kelly115,Reference Li, Srasuebkul, Reppermund and Trollor116} Rates for adults with intellectual disabilities across the included studies ranged from 8 to 53%. Four studies reported rates of multiple readmission (an individual discharged and readmitted more than once during the study period) of between 6 and 38% for specialist intellectual disability in-patient services.^{Reference Hurst, Nadarajah and Cumella1,Reference Trower, Treadwell and Bhaumik3,Reference Alexander, Piachaud and Singh5,Reference Lyall and Kelly115} The readmission rates to GMH in-patient services for adults with intellectual disabilities ranged from 9 to 36.3%,^{Reference Alexander, Piachaud and Singh5,Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7,Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52} with no significant difference in readmission rates between GMH and specialist intellectual disability in-patient services.^{Reference Alexander, Piachaud and Singh5,Reference Xenitidis, Gratsa, Bouras, Hammond, Ditchfield and Holt7} A single study reported significantly higher rates of readmission for those with ‘developmental disabilities’ compared with those without.^{Reference Lunsky and Balogh102} Those with borderline-to-moderate intellectual disabilities were noted to have higher readmission rates compared with those with a greater severity of intellectual disabilities in two studies.^{Reference Lunsky, White, Palucka, Weiss, Bockus and Gofine14,Reference Seager, Bell and O'Brien72} It was noted that generally there has been a significant reduction in readmission rates for individuals with intellectual disabilities over time.^{Reference Ganguly, Gore, Marston and Roy107,Reference Oxley, Sathanandan, Gazizova, Fitzgerald and Puri111} In one study, admission to accident and emergency departments was more likely following discharge from a psychiatric hospital for adults with intellectual disabilities, over a period of up to 26 months.^{Reference Li, Srasuebkul, Reppermund and Trollor116}

Measures of patient safety

Nine papers focused on measures of patient safety with adults with intellectual disabilities and/or autism.^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Larue, Goulet, Prevost, Dumais and Bellavance56,Reference Van Melle, Noorthoorn, Widdershoven, Mulder and Voskes71,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73,Reference Bakken and Hoidat74,Reference Sandhu and Tomlins78,Reference Xenitidis, Henry, Russell, Ward and Murphy104,Reference Mansell, Ritchie and Dyer112,Reference Turner and Mooney117}

Observation levels

Only two papers included information about observations levels for adults with intellectual disabilities within either GMH or specialist intellectual disability in-patient services.^{Reference Lohrer, Greene, Browning and Lesser68,Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73} Within GMH in-patient services, adults with intellectual disabilities required significantly higher staffing levels than those without intellectual disabilities,^{Reference Lohrer, Greene, Browning and Lesser68} and within specialist intellectual disability units, just under a third required specialist observation levels over a 15-month period.^{Reference Slevin, McConkey, Truesdale-Kennedy and Taggart73} Lohrer et al^{Reference Lohrer, Greene, Browning and Lesser68} reported ‘enhanced observations’ were used with 12.5% of adults without intellectual disabilities compared with 43.5% of adults with intellectual disabilities within GMH in-patient services. The use of enhanced observations with adults without intellectual disabilities is at a rate similar to that reported by others.^{Reference Neilson, Peet, Poole and Ledsham118,Reference Bowers and Park119}

Seclusion, physical interventions and pro re nata medication

The authors of six papers reported data about the use of seclusion and broader physical interventions within specialist intellectual disability in-patient services.^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Larue, Goulet, Prevost, Dumais and Bellavance56,Reference Van Melle, Noorthoorn, Widdershoven, Mulder and Voskes71,Reference Bakken and Hoidat74,Reference Mansell, Ritchie and Dyer112,Reference Turner and Mooney117} A single study reported data about the use of pro re nata medication,^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52} and two studies compared seclusion rates for in-patients with and without intellectual disabilities. Turner and Mooney^{Reference Turner and Mooney117} reported that adults with intellectual disabilities experienced seclusion at almost twice the rate of those without intellectual disabilities in a GMH in-patient service (6.4 v. 3.5%), but those admitted to specialist in-patient services spent significantly less time in seclusion than those with intellectual disabilities admitted to GMH services. In contrast, a recent study by Van Melle et al^{Reference Van Melle, Noorthoorn, Widdershoven, Mulder and Voskes71} reported that neither a diagnosis of intellectual disability or autism was associated with increased seclusion use in GMH services.

No further comparisons were made with in-patients without intellectual disabilities and/or autism, but some reductions in the use of physical interventions and pro re nata medication were associated with new programmes or changes in practice.^{Reference Chaplin15,Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52}

Within a survey of hospitals in a single study, higher use of seclusion and physical intervention were seen within the independent sector compared with the NHS in the UK, although the rates of patient injuries were the same.^{Reference Mansell, Ritchie and Dyer112} Comparing the data reported about the use of restrictive interventions with adults with intellectual disabilities with other studies indicated that they were used more frequently used.^{Reference Steinert, Lepping, Bernhardsgrutter, Conca, Hatling and Janssen121} Bakken and Hoidal^{Reference Bakken and Hoidat74} reported that 51% of in-patients with intellectual disabilities experienced seclusion, which was higher than that reported by other authors within low- and medium-secure forensic services.^{Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122}

Measures of patient experience

There were only eight papers that reported outcomes associated with the patient experience for adults with intellectual disabilities.^{Reference Hall, Parkes, Samuels and Hassiotis8,Reference van Minnen, Hoogduin and Broekman36,Reference Davies, Josham and Francis38,Reference Mansell, Ritchie and Dyer112,Reference Hellerud and Bakken123–Reference Beckman, Nelson and Labode126} All studies made use of measures of patient experience within specialist intellectual disability in-patient services, but made no comparisons with patients without intellectual disabilities. A single literature review included patient experiences of those with intellectual disabilities and/or autism within GMH services.^{Reference Chowdhury and Benson124}

Met and unmet need

Two studies measured met and unmet needs as reported by family, staff and patients, with admission being associated with increased met needs and decreased unmet needs.^{Reference Hall, Parkes, Samuels and Hassiotis8,Reference Hellerud and Bakken123} Hall et al^{Reference Hall, Parkes, Samuels and Hassiotis8} explored staff, patient and parent/carer views of in-patient needs compared with those receiving treatment in the community. Patients reported satisfaction with their met needs following community treatment; however, staff reports were not consistent, with staff identifying more unmet needs compared with those who had received in-patient care.^{Reference Hall, Parkes, Samuels and Hassiotis8} Hellerud and Bakken^{Reference Hellerud and Bakken123} reported that admission to in-patient services was associated with an increase in met needs, but families expressed concern about the risk of abuse, lack of specialist knowledge and challenges with understanding the detention process, as well as cultural and language differences in how mental health is understood. Two further studies explored patient views and experiences during admission within in-patient specialist intellectual disability services, and topics such as discomforting environments, staff support and relationships, being far from home and family, and limited opportunities to participate in decision-making were noted.^{Reference Chinn, Hall, Ali, Hassell and Patkas125,Reference Beckman, Nelson and Labode126}

Carer burden

Carer burden was examined within the only clinical trial included within this systematic review, and was noted to be high on initial baseline assessment.^{Reference van Minnen, Hoogduin and Broekman36} Carer burden did not increase for those who were allocated to outreach community-based treatment, and decreased slightly over time, but not significantly. Comparisons with those allocated to in-patient admission could not be made because of missing data.

Complaints and visits

It was noted in one study that fewer complaints and a higher number of visitors were reported for adults with intellectual disabilities within NHS specialist intellectual disability in-patient services in the UK, compared with the private/independent sector.^{Reference Mansell, Ritchie and Dyer112}

Assessments of quality of life

Two studies made references to assessments of quality of life: one following admission to a specialist intellectual disability assessment and treatment unit,^{Reference Davies, Josham and Francis38} and the other following discharge from GMH and/or specialist intellectual disability services.^{Reference Chowdhury and Benson124} Davies et al^{Reference Davies, Josham and Francis38} reported significant increases in quality of life at discharge (compared with at admission), indicating improvements in quality of life during admission. A literature review by Chowdhury and Benson^{Reference Chowdhury and Benson124} reported improvements in quality of life after discharge from in-patient services to homes in the community, with improvements being most prominent within the first 6 months to 1 year, after which improvements plateaued or declined.

Measures of effectiveness

Effectiveness, mostly length of stay, was considered within 19 studies.^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21,Reference Lin, Barbaree, Selick, Ham, Wilton and Lunsky27,Reference Halstead, Cahill, Fernando and Isweran50,Reference Esan, Chester, Gunaratna, Hoare and Alexander53,Reference Griffiths, Roychowdhury and Girardi58,Reference Butwell, Jamieson, Leese and Taylor80,Reference Chester, Vollm, Tromans, Kapugama and Alexander81,Reference Murphy, Bush and Puzzo83,Reference Verstegen, de Vogel, Huitema, Didden and Nijman85–Reference Reed, Russell, Xenitidis and Murphy89,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Wooster, McCarthy and Chaplin127,Reference Alexander, Crouch, Halstead and Piachaud130–Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132}

Length of stay

Forensic in-patients in the UK tended to have a shorter length of stay than those in similar services within The Netherlands.^{Reference Senn, Bulten, Tomlin and Vollm60} Within the UK, adults with intellectual disabilities were reported to have a longer length of stay than patients without intellectual disabilities within medium- and high-secure in-patient units,^{Reference Lin, Barbaree, Selick, Ham, Wilton and Lunsky27,Reference Butwell, Jamieson, Leese and Taylor80,Reference Alexander, Chester, Gray and Snowden131} but this difference was only found to be significant in one paper.^{Reference Alexander, Chester, Gray and Snowden131} A single study explored length of stay within low-secure units, but made no comparisons with those without intellectual disabilities.^{Reference Reed, Russell, Xenitidis and Murphy89} Previous studies reported data to suggest that people with intellectual disabilities who have forensic needs tend to have a lengthy hospital stay, which can exceed 10 years.^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21,Reference Chester, Vollm, Tromans, Kapugama and Alexander81} However, within one study, when length of stay was calculated using all admissions to secure/forensic in-patient services, adults with intellectual disabilities had a shorter length of stay than those without intellectual disabilities.^{Reference Chester, Vollm, Tromans, Kapugama and Alexander81} Stays within in-patient forensic services tended to be longer than those within GMH and specialist intellectual disability in-patient services,^{Reference Burge, Ouellette-Kuntz, Saeed, McCreary, Paquette and Sim52,Reference Axmon, Bjorne, Nylander and Ahlstrom100} and increased risk associated with criminal offending behaviours is likely to account for the longer length of stay within forensic hospitals.^{Reference Bonta and Andrews134}

Length of stay for individuals with intellectual disabilities were comparable across low- and medium-secure in-patient services within another study,^{Reference Wooster, McCarthy and Chaplin127} whereas a longer stay was noted for patients with intellectual disabilities and a co-occurring personality disorder.^{Reference Alexander, Chester, Gray and Snowden131,Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132} Whether detention in hospital was ordered by a court did not appear to lead to a longer length of stay.^{Reference Reed, Russell, Xenitidis and Murphy89}

For those with both autism and intellectual disabilities, one study reported no significant differences in length of stay compared with those with intellectual disabilities,^{Reference Esan, Chester, Gunaratna, Hoare and Alexander53} whereas in two further studies, adults with autism were reported to have a shorter length of stay.^{Reference Imran, Bodla, Asif, Shoukat and Azeem28,Reference Murphy, Bush and Puzzo83} However, there are studies indicating that adults with autism have longer stays within in-patient forensic services.^{Reference Murphy135,Reference Hare, Gould, Mills and Wing136} Senn et al^{Reference Senn, Bulten, Tomlin and Vollm60} reported that in-patients with autism were less prevalent within forensic services in the UK compared with The Netherlands.

Discharge pathway

Nine studies reported information relating to discharge outcomes for forensic services.^{Reference Halstead, Cahill, Fernando and Isweran50,Reference Esan, Chester, Gunaratna, Hoare and Alexander53,Reference Chester, Vollm, Tromans, Kapugama and Alexander81,Reference Devapriam, Fosker, Chester, Gangadharan, Hiremath and Alexander87,Reference Reed, Russell, Xenitidis and Murphy89,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Wooster, McCarthy and Chaplin127,Reference Alexander, Crouch, Halstead and Piachaud130,Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132}

Discharges from secure/forensic in-patient services were frequently characterised by involvement with another service or care provider, rather than absolute discharge to the community. As perhaps would be expected, there was evidence that low-secure services discharged more frequently to the community, with earlier studies showing more discharges to a home or the family home and later studies more likely to describe discharge to ‘group’ homes or residential care.^{Reference Wooster, McCarthy and Chaplin127,Reference Alexander, Crouch, Halstead and Piachaud130} Within several papers, it was reported that between 20 and 91% of those discharged within the UK remained subject to the Mental Health Act (1983).^{Reference Halstead, Cahill, Fernando and Isweran50,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Wooster, McCarthy and Chaplin127,Reference Alexander, Crouch, Halstead and Piachaud130}

Individuals within medium- and high-secure care tended to stay within secure in-patient services, and discharges tended to be associated with transfer to another secure in-patient setting.^{Reference Halstead, Cahill, Fernando and Isweran50,Reference Reed, Russell, Xenitidis and Murphy89} This was not only illustrated by discharge data, but also by the source of the admission as described by Chester et al,^{Reference Chester, Vollm, Tromans, Kapugama and Alexander81} who reported that 51.5% of patients with intellectual disabilities were admitted from medium-secure, 10.6% from low-secure and 13.6% from high-secure settings. A similar pattern was found for patients without intellectual disabilities, although this group were significantly more likely to be admitted from a high-secure service and significantly less likely to be admitted to high- or medium-secure services direct from the community. They also noted that patients with intellectual disabilities were less likely to be admitted to hospital via a court-ordered admission, and more likely to experience transfer to services of the same or increasing security than patients without intellectual disabilities.^{Reference Chester, Vollm, Tromans, Kapugama and Alexander81} For those with intellectual disabilities and a diagnosis of personality disorder, there were no differences in discharge outcomes within a forensic in-patient service compared with those with intellectual disabilities without a diagnosis of personality disorder.^{Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132}

Clinical outcomes

Numerous clinical or risk assessments and outcome measures were discussed within five papers about admission to forensic in-patient services.^{Reference Griffiths, Roychowdhury and Girardi58,Reference Chester, Vollm, Tromans, Kapugama and Alexander81,Reference Morrissey, Hobson, Faulkner and James88,Reference Reed, Russell, Xenitidis and Murphy89,Reference Alexander, Chester, Gray and Snowden131} These included the HoNOS scores for people with intellectual disabilities;^{Reference Roy, Matthews, Clifford, Fowler and Martin37} the Historical, Clinical and Risk Management – 20 (HCR-20);^{Reference Webster, Douglas, Eaves and Hart49} the Psychopathy Checklist Screening Version;^{Reference Hart, Cox and Hare51} and mental health and behaviour measures, such as the Emotional Problems Scale – Behaviour Rating Scale and Self-Report Inventory.^{Reference Prout and Strohmer137} Most comparisons were made between groups of adults with intellectual disabilities, where authors demonstrated that risk and symptoms were improved at discharge compared with admission, lower for those who had been discharged compared with current in-patients, and higher for those who were subject to more restrictive practices.^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21,Reference Griffiths, Roychowdhury and Girardi58,Reference Murphy, Bush and Puzzo83} These findings suggest that admission is associated within clinical improvements over time.

There was some evidence that adults with intellectual disabilities who have associated forensic needs tend to score higher on the HCR-20 compared with those without intellectual disabilities.^{Reference Chester, Vollm, Tromans, Kapugama and Alexander81} In a different study, this was also the case for adults with intellectual disabilities who had a personality disorder, who scored higher on the HCR-20 than those with intellectual disabilities without a diagnosis of personality disorder and those with personality disorder without intellectual disabilities.^{Reference Alexander, Chester, Gray and Snowden131} In a further study, HoNOS scores for adults with Asperger syndrome significantly decreased from admission to discharge, and higher scores on this measure were not associated with increased use of seclusion for this patient group.^{Reference Griffiths, Roychowdhury and Girardi58}

Criminal offending or ‘offending-like’ behaviours

Further offending behaviours or reconvictions (including aggression and violence) were examined in eight papers exploring forensic in-patient services for individuals with intellectual disabilities.^{Reference Halstead, Cahill, Fernando and Isweran50,Reference Chester, Vollm, Tromans, Kapugama and Alexander81,Reference Verstegen, de Vogel, Huitema, Didden and Nijman85,Reference Morrissey, Hobson, Faulkner and James88,Reference Reed, Russell, Xenitidis and Murphy89,Reference Williams and Rose128,Reference Alexander, Crouch, Halstead and Piachaud130,Reference Alexander, Chester, Gray and Snowden131} Reconviction rates were lower than displays of ‘offending-like behaviours’, with the former ranging from 3 to 11% for those discharged, and the latter ranging from 30 to 58% over follow-up periods of 5–12 years.^{Reference Hart, Cox and Hare51,Reference Alexander, Crouch, Halstead and Piachaud130} A diagnosis of personality disorder was associated with a higher post-discharge conviction rate in adults without intellectual disabilities, while individuals with intellectual disabilities and a co-occurring personality had a higher post-discharge conviction rate than individuals with intellectual disabilities without personality disorder.^{Reference Alexander, Chester, Gray and Snowden131} In a single study within the UK, there was evidence that more frequent aggression was observed by those with intellectual disabilities detained under Part II compared with Part III of the Mental Health Act, 1983.^{Reference Reed, Russell, Xenitidis and Murphy89} Challenging behaviour and violent incidents were noted to reduce over longer admissions,^{Reference Morrissey, Hobson, Faulkner and James88} and further instances of offending-like behaviours were associated with readmission and transfers to higher-security services.^{Reference Alexander, Crouch, Halstead and Piachaud130} Those with intellectual disabilities and/or autism were not more likely to display physical violence compared with those with intellectual disabilities and/or autism.^{Reference Verstegen, de Vogel, Huitema, Didden and Nijman85}

Readmission

Readmission rates for adults with intellectual disabilities within in-patient forensic services were reported to vary from 20 to 44% across low-, medium- and high-secure services across five papers.^{Reference Lin, Barbaree, Selick, Ham, Wilton and Lunsky27,Reference Halstead, Cahill, Fernando and Isweran50,Reference Morrissey, Hobson, Faulkner and James88,Reference Wooster, McCarthy and Chaplin127,Reference Alexander, Crouch, Halstead and Piachaud130}

Readmission to medium- and low-secure units was associated with discharge to the community, along with multiple changes to residence, rather than discharge or transfer to another in-patient service; this is unsurprising, considering that this group remained within in-patient services.^{Reference Halstead, Cahill, Fernando and Isweran50,Reference Alexander, Crouch, Halstead and Piachaud130} Readmission appeared to be because of criminal offending or behaviour that challenges, rather than mental ill health.^{Reference Alexander, Crouch, Halstead and Piachaud130} However, in a single study comparing adults with and without intellectual disabilities who have forensic histories, there was no difference in readmission rates over a 10-year period.^{Reference Lin, Barbaree, Selick, Ham, Wilton and Lunsky27}

Measures of patient safety

Aspects of patient safety were examined within ten studies.^{Reference Esan, Chester, Gunaratna, Hoare and Alexander53,Reference Griffiths, Roychowdhury and Girardi58,Reference Huitema, Verstegen and de Vogel82–Reference Verstegen, de Vogel, Huitema, Didden and Nijman85,Reference Morrissey, Hobson, Faulkner and James88,Reference Reed, Russell, Xenitidis and Murphy89,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132}

Use of observation levels, seclusion rates and physical intervention

A small number of papers explored observation levels, seclusion rates and physical interventions within in-patient forensic services.^{Reference Esan, Chester, Gunaratna, Hoare and Alexander53,Reference Griffiths, Roychowdhury and Girardi58,Reference Murphy, Bush and Puzzo83,Reference Reed, Russell, Xenitidis and Murphy89,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132} Studies predominantly reported data about rates of seclusion, physical intervention and/or rapid tranquilisation or enhanced observations. No significant differences were noted in use of seclusion or physical restraint for those with and without intellectual disabilities within high-security hospitals.^{Reference Ray, Simpson, Jones, Shatokhina, Thakur and Mulsant84} Several papers^{Reference Esan, Chester, Gunaratna, Hoare and Alexander53,Reference Alexander, Hiremath, Chester, Green, Gunaratna and Hoare122,Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132} explored patient safety outcomes in a medium-secure service across a 6-year period, and reported no significant differences in use of seclusion, physical intervention or observation levels between adults with intellectual disabilities with and without comorbid personality disorder.^{Reference Morrissey, Hobson, Faulkner and James88}

However, the authors of one paper reported significantly higher levels of enhanced observations and use of physical interventions for in-patients with autism compared with in-patients without autism.^{Reference Esan, Chester, Gunaratna, Hoare and Alexander53} Further papers reported that the use of seclusion with adults with autism in medium- and low-secure services was higher than those with a diagnosis of paranoid schizophrenia, but lower than those with a diagnosis of emotionally unstable personality disorder or antisocial personality disorder.^{Reference Alexander, Green, O'Mahony, Gunaratna, Gangadharan and Hoare132} There was some evidence to indicate that in-patients with autism within high-secure hospitals are secluded more frequently and for longer, compared with in-patients without autism.^{Reference Murphy, Bush and Puzzo83}

Reed et al^{Reference Reed, Russell, Xenitidis and Murphy89} compared those detained under Part III and Part II of the Mental Health Act, 1983, within the UK in a low-secure unit. They noted the higher use of physical restraint, intervention and seclusion, and more instances of aggression, among those detained under Part II compared with Part III (which are those who were admitted to hospital as a result of criminal proceedings). Those detained under Part II were more likely to have a diagnosis of pervasive developmental disorder, which included autism, whereas those detained under Part III were more likely to have a diagnosis of personality disorder and present with self-harm.^{Reference Reed, Russell, Xenitidis and Murphy89}

Measures of patient experience

Four studies investigated aspects of the patient experience within forensic in-patient services.^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21,Reference Williams, Thrift and Rose23,Reference Murphy and Mullens59,Reference Cheshire, McCarthy, Devapriam, Chester, Graham and Grace129} A systematic review and Delphi study^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21} identified patient and carer experience as an important indicator of service quality within in-patient forensic services for people with intellectual disabilities and/or autism. Three studies, excluding the systematic review by Morrissey et al,^{Reference Morrissey, Langdon, Geach, Chester, Ferriter and Lindsay21} investigated patient experience within in-patient forensic services,^{Reference Williams, Thrift and Rose23,Reference Murphy and Mullens59,Reference Cheshire, McCarthy, Devapriam, Chester, Graham and Grace129} with one focusing specifically on family and home visits.^{Reference Cheshire, McCarthy, Devapriam, Chester, Graham and Grace129} Two papers made use of semi-structured interviews and identified hospital admission as ‘helpful’, although the environment was characterised as ‘noisy’ and ‘stressful’, with both studies recognising loss of freedoms and restrictions of personal items as challenging for patients.^{Reference Williams, Thrift and Rose23,Reference Murphy and Mullens59} Restriction of items associated with circumscribed interests was noted to be difficult for adults with autism. Despite these restrictions, satisfaction with quality of life were comparable or higher for adults with autism within high-security settings compared with other detained forensic patient groups.^{Reference Murphy and Mullens59} Williams et al^{Reference Williams, Thrift and Rose23} interviewed a small sample of seven women with intellectual disabilities detained in hospital. They reported that these women found hospital admission helpful, including the treatment offered, but at the same time, they found their setting undesirable, experienced some interpersonal conflict with other in-patients and wanted to live in the community.

Family contact and home visits were shown to be high in a retrospective case file review of in-patients within a medium-secure, low-secure and ‘locked rehab’ forensic service, with 81% maintaining some degree of contact with their relatives. This included 44% receiving a family visitor and 54% undertaking a home visit during a 12-month period.^{Reference Cheshire, McCarthy, Devapriam, Chester, Graham and Grace129}

Measures of effectiveness

There were 20 different studies that investigated aspects of effectiveness associated with admission to a psychiatric in-patient service for children and adolescents.^{Reference Kalb, Stuart and Vasa25,Reference Imran, Bodla, Asif, Shoukat and Azeem28,Reference Theodoratos, McPherson, Franklin, Tonge, Einfeld and Lennox30,Reference Medel-Herrero and Gomez-Beneyto31,Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33,Reference Croteau, Mottron, Dorais and Tarride61–Reference Kuriakose, Filton, Marr, Okparaeke, Cervantes and Siegel67,Reference Chaplin, Roach, Johnson and Thompson90–Reference Donnelly, Cervantes, Okparaeke, Stein, Filton and Kuriakose95,Reference Kerkela, Gyllenberg, Gissler, Sillanmaki, Keski-Santti and Hinkka-Salomaki138,Reference Livanou, Singh, Liapi and Furtado139}

Length of stay

Mean length of stay was available from 13 papers for children and adolescents (minimum 13.4 days, maximum 263 days).^{Reference Imran, Bodla, Asif, Shoukat and Azeem28,Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33,Reference Croteau, Mottron, Dorais and Tarride61–Reference Lokhandwala, Khanna and West-Strum63,Reference Cervantes, Kuriakose, Donnelly, Filton, Marr and Okparaeke66,Reference Kuriakose, Filton, Marr, Okparaeke, Cervantes and Siegel67,Reference Chaplin, Roach, Johnson and Thompson90–Reference Donnelly, Cervantes, Okparaeke, Stein, Filton and Kuriakose95} Length-of-stay data indicated that a shorter length of stay was associated with admission to specialist higher-dependency intellectual disability in-patient services compared with secure open in-patient services^{Reference Smith and Berney93} and GMH in-patient services.^{Reference Chaplin, Roach, Johnson and Thompson90} Further still, one group of authors reported that there were no differences in length of stay for children and adolescents with or without autism who also had intellectual disabilities.^{Reference Siegel, Milligan, Chemelski, Payne, Ellsworth and Harmon91} However, a database review of public health services in Canada noted longer psychiatric hospital stays for adolescents and young adults with autism compared with those in infancy and childhood.^{Reference Croteau, Mottron, Dorais and Tarride61} The findings from three further studies indicated that the implementation of an autism-specific care pathway shortened length of stay for children with autism, but not significantly.^{Reference Cervantes, Kuriakose, Donnelly, Filton, Marr and Okparaeke66,Reference Kuriakose, Filton, Marr, Okparaeke, Cervantes and Siegel67,Reference Donnelly, Cervantes, Okparaeke, Stein, Filton and Kuriakose95}

Two papers focused specifically on adolescent GMH in-patient services during the COVID-19 pandemic,^{Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33,Reference Diaz de Neira, Blasco-Fontecilla, Garcia Murillo, Perez-Balaguer, Mallol and Forti62} noting a shorter in-patient length of stay after the COVID-19 outbreak, and although based on small numbers, a shorter length of stay was noted for adolescents with autism compared with those with both autism and intellectual disabilities.^{Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33}

Discharge pathway

Only one paper explored the discharge pathway from specialist intellectual disability in-patient services,^{Reference Smith and Berney93} and another explored discharge pathways from forensic medium-secure units.^{Reference Livanou, Singh, Liapi and Furtado139} Smith and Berney^{Reference Smith and Berney93} examined discharges of children and adolescents with moderate intellectual disabilities from one open unit, and those with mild intellectual disabilities from a different open or low-secure unit. Both Smith and Berney^{Reference Smith and Berney93} and Livanou et al^{Reference Livanou, Singh, Liapi and Furtado139} reported that discharges from secure units were most often to another specialist and highly staffed unit, including forensic in-patient or secure services, sometimes for adults. Discharge from the open units was more likely to be back to the family home.^{Reference Smith and Berney93} It was noted that males with neurodevelopmental disabilities, including those with intellectual disabilities and autism, were more likely to be transferred to an adult secure psychiatric service (low, medium or high), but the authors did not report whether these services were specialist.^{Reference Livanou, Singh, Liapi and Furtado139}

Clinical outcomes

Four studies measured symptoms over time following in-patient admission for children and adolescents with intellectual disabilities and/or autism.^{Reference Imran, Bodla, Asif, Shoukat and Azeem28,Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33,Reference Chaplin, Roach, Johnson and Thompson90,Reference Siegel, Doyle, Chemelski, Payne, Ellsworth and Harmon94} The authors of two studies reported improved symptoms following admission to a GMH in-patient service for children with intellectual disabilities and/or autism.^{22,Reference Ozbaran, Kose, Barankoglu, Dogan and Bildik33} There was also evidence to indicate improvements in symptoms following admission to a specialist intellectual disability in-patient service that included children with autism.^{Reference Siegel, Doyle, Chemelski, Payne, Ellsworth and Harmon94} The authors of the final study to examine clinical outcomes reported that children with intellectual disabilities and/or autism admitted to specialist intellectual disability in-patient services had fewer symptoms and problems at discharge (compared with admission), than children admitted to GMH in-patient services.^{Reference Chaplin, Roach, Johnson and Thompson90} However, overall, the degree of symptoms and problems was higher for children and adolescents with intellectual disabilities and/or autism compared with those without intellectual disabilities and/or autism, at both admission and discharge.

Admission and readmission

Ten studies reported admission and readmission rates.^{Reference Kalb, Stuart and Vasa25,Reference Theodoratos, McPherson, Franklin, Tonge, Einfeld and Lennox30,Reference Medel-Herrero and Gomez-Beneyto31,Reference Croteau, Mottron, Dorais and Tarride61,Reference Diaz de Neira, Blasco-Fontecilla, Garcia Murillo, Perez-Balaguer, Mallol and Forti62,Reference Nayfack, Huffman, Feldman, Chan, Saynina and Wise64,Reference Robinson, Menezes, Mullin and Cook65,Reference Gabriels, Agnew, Beresford, Morrow, Mesibov and Wamboldt92,Reference Kerkela, Gyllenberg, Gissler, Sillanmaki, Keski-Santti and Hinkka-Salomaki138,Reference Livanou, Singh, Liapi and Furtado139} Evidence suggested that children and adolescents with mild intellectual disabilities were more likely to be admitted to GMH in-patient services, and those with more severe intellectual disabilities were more likely to be admitted to specialist intellectual disability in-patient services.^{Reference Chaplin, Roach, Johnson and Thompson90,Reference Smith and Berney93} Males were more likely to be admitted to forensic in-patients services.^{Reference Livanou, Singh, Liapi and Furtado139} There was also evidence from a single study that readmission rates to specialist intellectual disability in-patient services were lower than that seen following discharge from GMH in-patient services for children and adolescents with intellectual disabilities and/or autism.^{Reference Gabriels, Agnew, Beresford, Morrow, Mesibov and Wamboldt92}

For in-patients with autism, admissions were noted by some groups as disproportionately higher than for those without autism, and increased over time.^{Reference Kalb, Stuart and Vasa25,Reference Medel-Herrero and Gomez-Beneyto31,Reference Kalb, Stuart, Freedman, Zablotsky and Vasa41,Reference Lokhandwala, Khanna and West-Strum63,Reference Smith and Berney93} This included increased admissions of children with autism with and without intellectual disabilities to non-psychiatric settings for mental ill health.^{Reference Croteau, Mottron, Dorais and Tarride61,Reference Diaz de Neira, Blasco-Fontecilla, Garcia Murillo, Perez-Balaguer, Mallol and Forti62,Reference Robinson, Menezes, Mullin and Cook65} Although Kalb et al^{Reference Kalb, Stuart and Vasa25} noted an increased admission rate for those with autism compared with those without autism, they reported that there had been no change in the number of children and adolescents with autism presenting to accident and emergency departments because of mental ill health or behaviour that challenges, in the USA between the years 2010 and 2013. However, in another study^{Reference Nayfack, Huffman, Feldman, Chan, Saynina and Wise64} from the USA with just over 2 million participants, a significant increase in hospital admission during the years 1999–2009 was associated with a diagnosis of autism, excluding intellectual disabilities, and the most cited reason for admission was psychiatric disorder; teenagers with autism were more likely to be admitted, a finding echoed by data from Canada.^{Reference Croteau, Mottron, Dorais and Tarride61} Within these two studies, psychiatric care was the most expensive medical cost incurred for children and young people with autism. A substantial increase was noted in the number of discharges of children and adolescents with autism within another study,^{Reference Nayfack, Huffman, Feldman, Chan, Saynina and Wise64} but there was no associated increase in rates of admission for children and adolescents who had both autism and intellectual disabilities.^{Reference Nayfack, Huffman, Feldman, Chan, Saynina and Wise64} A single study noted a decrease in child and adolescent admissions to both the emergency room and psychiatric in-patient units for those diagnosed with autism during the first month of the COVID-19 outbreak.^{Reference Diaz de Neira, Blasco-Fontecilla, Garcia Murillo, Perez-Balaguer, Mallol and Forti62}

Measures of patient safety

The literature about patient safety within child and adolescent in-patient services for those with intellectual disabilities and/or autism was scant. There were only three published papers within this domain, and they were about the same clinical service, using the same data;^{Reference Cervantes, Kuriakose, Donnelly, Filton, Marr and Okparaeke66,Reference Kuriakose, Filton, Marr, Okparaeke, Cervantes and Siegel67,Reference Donnelly, Cervantes, Okparaeke, Stein, Filton and Kuriakose95} both physical interventions and intramuscular injection as pro re nata medication were examined when used with children and adolescents with autism. The authors reported that following the implementation of a new, autism-specific in-patient care pathway, the use of physical interventions and intramuscular injection decreased when compared with the previous care pathway.^{Reference Cervantes, Kuriakose, Donnelly, Filton, Marr and Okparaeke66,Reference Kuriakose, Filton, Marr, Okparaeke, Cervantes and Siegel67}