The benefits and harms of inpatient involuntary psychiatric treatment: a scoping review

Abstract

This scoping review examined quantitative research comparing involuntary inpatient groups with voluntary inpatients or other comparator group. Ten themes were identified: patient knowledge of legal status, experienced or perceived coercion, effects on medication use, clinical effects measured on outcome scales, effects on psychiatric readmission, use of restraints and seclusion, effects on suicide and deaths, patient satisfaction, length of stay and carer experiences. The review found that involuntary inpatient admission was associated with harms including increased subjective and objective coercion, increased cost and decreased patient satisfaction. In addition, it found that there may be significant confusion among both voluntary and involuntary patients regarding their legal rights. However, patients admitted on an involuntary basis experienced greater improvements in symptoms and function, possibly due to greater symptom burden prior to admission. Involuntary treatment carries the potential for both benefit and harms that should be acknowledged and mitigated by service providers.

Introduction

Involuntary treatment for psychiatric illness has become an area of increasing scrutiny and debate, with a global political push to decrease the use of coercive care in mental health.

The United Nations High Commissioner for Human Rights has called for the outright abolition of all forms of involuntary psychiatric treatment, in part on the grounds that it constitutes discrimination on the basis of disability (1). However, this has not been implemented in any jurisdiction, in part because of the absence of any well-developed alternative treatment strategy to ensure safe and effective care (2).

The decision to admit a person for psychiatric care, and whether this is on an involuntary rather than voluntary basis, likely reflects a complex interplay between factors relating to the individual, their illness, the individual provider or episode of care and the legal and cultural setting in which the care occurs.

The international literature shows wide disparities in the use of involuntary inpatient treatment between jurisdictions that do not appear explained by the relevant legal frameworks governing involuntary treatment (3). Additionally, a wide variety of socioeconomic factors may put people at a higher risk of receiving their treatment on an involuntary, rather than voluntary, basis. These include non-white ethnicity (4), male gender, single marital status, unemployment and receiving welfare benefits (5).

In Australia, where this review was conducted, rates of involuntary treatment have increased despite policies to decrease its use, as indeed they have in much of the world. In fact, Australia had one of the highest rates of involuntary treatment per 100,000 population of 22 countries across Europe, Australia and New Zealand, with an average annual increase of 3.44% (3).

While the push to either reduce or abolish involuntary inpatient admission has generally been driven by politico-legal principles, research examining the effects of such admissions is limited.

The lack of well-developed alternatives to involuntary admission also limits the possibility of well-constructed, randomised controlled studies. As such, most of the literature involves naturalistic or correlational studies.

Two previous reviews of quantitative studies examining the outcomes of involuntary treatment undertaken in 2006 and 2008 identified only 18 and 41 studies for inclusion, respectively (6,7), while a recent scoping review identified 57 studies for synthesis (8).

The scoping review, which analysed findings on the benefits and harms of involuntary treatment found in 112 primary quantitative research studies, thus represents a significant contribution to the international literature on this topic.

Method

This scoping review that was the basis of this publication was commissioned by the Independent Review of Compulsory Treatment and Assessment Criteria and Alignment with Decision-Making Laws, an independent panel reviewing mental health law in the Australian state of Victoria. The panel was not involved in developing the method for this review.

Search strategy

The protocol for this review was initially registered as a rapid review with PROSPERO (CRD42023397884). However, because of the nature of the research question, the identified papers and the available resources it was more appropriate to undertake a scoping review. Ethical approval was not required as this article does not contain any studies with human participants or animals performed by any of the authors. We followed guidelines from the Joanna Briggs Institute on the conduct of scoping reviews (9).

The following search terms were entered into PubMed/Medline in searches undertaken between March 2023 and December 2023: ((involuntar*) OR (coerc*) OR (compulsor*)) AND ((admission) OR (detention) OR (commit*) OR (treatment)) AND ((psychiatr*) OR (mental*)), with results included from 1980 to the current day.

Inclusion/exclusion criteria

Studies were included that reported quantitative data on outcomes for involuntary inpatients and a comparator group (usually voluntary inpatients). Studies were excluded if they reported only qualitative data, had no comparator groups or were existing systematic reviews or metanalyses, Studies reporting on patient groups with primarily anorexia nervosa or substance use disorders were also excluded owing to the unique issues involved in the treatment of both patient groups and because the compulsory treatment of each group often involves reliance on legal warrant that lies outside of standard mental health legislation.

Data extraction and synthesis

Given the nature of the included studies, it was not appropriate to undertake a meta-analysis. We therefore conducted a narrative synthesis according to broad themes. The search and initial screening was undertaken by one author (A.C.), while abstract and full-text review was undertaken by two (A.C. and C.J.R.), with any disagreements resolved by consensus.

Results and discussion

The search returned 8289 citations that underwent title–abstract screen. From title–abstract screen 300 records proceeded to further review. Of these, 112 papers were included in the final analysis, with most coming from Europe and the UK (see Figure 1: Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow chart and Appendix: included studies).

Figure 1.

Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow-chart.

We identified the following 10 main themes: patient knowledge of legal status, experienced or perceived coercion, effects on medication use, clinical effects measured on outcome scales, effects on psychiatric readmission, use of restraints and seclusion, effects on suicide and death rates, patient satisfaction, length of stay and carer experiences.

Theme 1: Patient knowledge of legal status

All studies that examined patient knowledge of legal status found significant confusion among both people treated on an involuntary and voluntary basis regarding their legal rights or status (10–15). The proportion of people in involuntary care who did not know their legal status ranged from 12% (12) to 45% (11,15), with a median of 28.5%. Among voluntarily admitted people, the proportion who did not correctly state their legal status ranged from 1% to 12% (12,15).

While no studies have examined this phenomenon in an Australian setting, data from NSW inpatient admissions found information regarding patient legal status was missing from 3.8% of records of inpatient psychiatric admissions (16).

Theme 2: Experienced or perceived coercion

Coercion in mental health care is multifaceted, and can range from formal or objective coercion such as seclusion, restraint or involuntary treatment, to subjective or informal coercion, such as pressure to make decisions or lack of agency over care (17), and patient and family member experiences of coercion reflect this complexity. Involuntary treatment is by definition associated with objective coercion, but it was also associated with an increased risk of the admission being perceived as coercive (for example experiencing a lack of control or agency) or procedurally unfair when compared to those receiving voluntary care (10,11,15,18–31). In general, perceived coercion was associated with decreased involvement in, and control over, care (21,31,32). By contrast, families did not recognise the experience as coercive to the same degree (21). Decreased involvement in care was also associated with involuntary status (20,31,32).

As seen in Theme 1, while most patients were aware that psychiatric treatment could be provided on an involuntary basis, the high degree of confusion regarding legal status and the coercive practices in inpatient settings led to voluntary patients also experiencing a high degree of perceived coercion during their admission. As a result, perceptions of coercion were not necessarily related to objective legal status (12,33), with high degrees of perceived coercion found among those receiving voluntary care (11,13–15,27,29).

Theme 3: Effects on medication use

A small number of studies suggested that involuntary admission was associated with a higher burden of psychotropic medication use in the short term (34,35).

For instance, a four-year Australian cohort study investigating the association between psychotropic medication burden and involuntary treatment under the Mental Health Act 2016 (Qld) found that involuntary admission was associated with a nine-fold risk of being discharged on more than one antipsychotic medication, and about one and a half times greater likelihood of being prescribed high-dose antipsychotic treatment than for voluntary care (35). This is despite the limited evidence for dual-antipsychotic use and the associated adverse effects, including increased side-effect burden and mortality (36).

There were mixed findings in the longer term. For example, one study of 119 patients found involuntary treatment was subsequently associated with lower adherence to medication 5 years after admission (37). By contrast, two studies found no association between legal status or perceived coercion and adherence to treatment plans (38,39), or medication as measured by blood levels over two years (22). However, self-rated medication adherence was lower and self-reported coercion greater (22).

Theme 4: Clinical effects measured on outcome scales

The clinical implications of receiving psychiatric inpatient admission on an involuntary basis were assessed in several studies using a variety of clinical scales including the Global Assessment of Functioning, the Health of the Nations Outcomes Scale and the Brief Psychiatric Rating Scale to assess improvement.

In general, these studies found either no difference in the clinical effects of involuntary admission (27,40–45) or greater improvements in clinical symptoms and functioning than for voluntary patients (46,47). This may be because people admitted involuntarily tended to display poorer function and worse symptoms at admission and so benefited to a greater degree than voluntary admissions as a result of regression to the mean. Another explanation is that any negative effects of involuntary admission may be related to experienced coercion, which can also be seen in many voluntary admissions (27,48). However, involuntary admission may be associated with difficulties establishing clinical rapport and patient insight into illness (12,49,50).

Four studies examined the specific outcome of posttraumatic stress disorder (PTSD) following involuntary and voluntary hospital admission. PTSD symptoms were relatively common in people who had experienced any psychiatric admission (prevalence range: 8.2% to 51%), but there was no increase among those admitted on an involuntary basis (51–54). Only one study found an association between perceived trauma from admission and involuntary status (55).

Theme 5: Readmission

Healthcare systems globally have attempted to decrease readmission after discharge in an attempt to decrease costs and adverse patient outcomes (56,57). The literature regarding rehospitalisation following involuntary admission is mixed. Some studies found that following an involuntary admission people were more likely to be re-hospitalised than following voluntary admissions, over a wide range of time-periods (58–68). However, these studies generally did not control for severity of illness of baseline, which is likely to be a risk factor for readmission.

By contrast, two studies found that overall readmission was not higher following involuntary admission (69,70) although there was an association with involuntary readmission, possibly indicating less therapeutic engagement (71–75).

Theme 6: Use of restraints and seclusion

A similar cycle of coercive care provision may also be evident during admission, with the available literature indicating that once a person was admitted as an involuntary patient they were more likely to be subject to use of coercive treatment modalities such as restraint and seclusion than people admitted on a voluntary basis (34,76–88), and may be more likely to display aggressive behaviours (89).

While it might appear self-evident that seclusion and restraint would be more common in involuntary admissions than voluntary admissions, it is widely recognised that the use of seclusion and restraint is linked to detrimental outcomes for patients including increased risk of death, and their use is linked to cultural and institutional factors within organisations including staff attitudes and staffing levels (90). The use of seclusion and restraint also varies drastically between services, jurisdictions and countries, with up to 300-fold differences in the rate of use found in one review (91).

Theme 7: Suicide and death

Although the prevention of suicide is a common reason for involuntary treatment (92), only one of the included studies found that involuntary admission decreased the risk of suicide compared to voluntary admission (93), while another found an increased risk of presentations to emergency departments with suicidal behaviour after involuntary treatment orders were rescinded by independent review (94). One ecological study found a negative correlation between rates of involuntary admissions and general population suicide rates in both sexes (95). Five studies found no difference in the risk of suicide or all-cause mortality among involuntarily and voluntarily admitted patients (71,96,97,100).

However, five studies found an increased risk of suicide for people admitted involuntarily (98–102), and one study found that involuntary admission was associated with a greater risk of all-cause mortality (with no deaths attributable to suicide in either group) (103).

Theme 8: Satisfaction with care

In general, most literature indicates that people are less satisfied with involuntary care as measured by structured assessment tools including the Client Assessment of Treatment Scale or the Client Satisfaction Questionnaire (10,13,66,104–110) and measures of humiliation and negative affective response (24,110,111).

However, four studies found no negative effect on patient satisfaction or dignity (112–114). A further study found that while satisfaction was initially lower among involuntary patients, post-discharge satisfaction was similar between groups (115). Finally, one study of more than 3000 involuntary patients found that almost 30% wanted their admission when surveyed at the time of admission (116).

Theme 9: Length of stay

Involuntary treatment was generally associated with longer length of stay than was voluntary care (58,68,89,117–120), with the exception of one study (121).

This may be in part because involuntary treatment is often used for people with more severe illness or with conditions such as psychosis that take a greater period of time to resolve (89,118,119), although other factors such as logistical and bureaucratic issues or bed availability may also affect length of stay for involuntary patients (64,68,120). Most legal oversight of involuntary inpatient admission grants orders for defined periods of time, and delays in these reviews occurring or the process of granting longer orders may also be associated with longer length of stay or decreased review of patient rights in some jurisdictions (92,122). As a result of the longer lengths of stay, involuntary hospitalisation has been associated with increased costs (123), which has implications for distributive justice in service planning and provision.

Theme 10: Carers

Two papers found that involuntary treatment reduced carer satisfaction (107,124), while one found no difference in satisfaction between carers of voluntary or involuntary patients (29) and another no association with legal status and perceived carer burden (125). Two papers examining perceived coercion found that involuntary admission was more likely to lead to differences in perceived coercion between patients and their families (21,126).

Discussion

This scoping review of the benefits and harms of involuntary psychiatric admission has found mixed results depending on the outcome examined and whether respondents are people with a mental illness or their families or carers. Involuntary admission can lead to significant improvement in symptoms of mental illness and function in the community, which can sometimes exceed that seen in voluntary controls. This may be because people admitted involuntarily displayed poorer function and worse symptoms at admission and so benefited to a greater degree than voluntary admissions as a result of regression to the mean. Another explanation is that any negative effects of involuntary admission may be related to experienced coercion, which can also be seen in many voluntary admissions given the confusion around legal status as identified in Theme 1.

However, this review has found that involuntary admission may in and of itself be associated with a number of harms. Of concern was the significant confusion among people on both voluntary and involuntary care concerning their legal status or rights when admitted to hospital, which indicates that patients do not adequately understand their legal rights in hospital.

Involuntary admission may trigger a ‘cycle of coercion’ in which the initial act of admission is linked to poorer clinical rapport, an increase in both perceived and objective measures of coercive care, increased likelihood of further coercive interactions with the healthcare system in future, increased health care costs and decreased satisfaction with care.

In addition, we found little evidence that involuntary admission was protective against suicide, and some evidence that it may in fact be a risk factor for inpatient suicide. This is in line with one meta-analysis of inpatient suicide, which reported an 87% increased risk of suicide among people admitted involuntarily (127). It has been proposed that psychiatric inpatient admission in and of itself may increase the likelihood of some people to attempt suicide, in a phenomenon termed ‘nosocomial suicide’ (128). Nosocomial harms associated with involuntary admission should therefore be acknowledged in service planning and provision.

However, the literature examining the benefits and harms of involuntary treatment is significantly affected by a number of limitations. The first and foremost is the difficulty in conducting randomised controlled trials of involuntary admission, which means that studies looking at the effect of involuntary admission generally use convenience or observational samples of existing admissions so limiting the ability to control for confounding variables such as severity of illness. The lack of alternatives for safe and effective care for people currently deemed unwell enough to require involuntary admission would make randomised controlled trials difficult and, in many circumstances, unethical to undertake and leaves a number of unanswered questions regarding the benefits and harms for patients of being treated in such an alternative system.

Conclusion

Although involuntary psychiatric admission can lead to improvements in symptoms and function, there are mixed findings in terms of other possible benefits, as well as potential serious harms that should be acknowledged and mitigated by mental health services. More research is needed to better understand the benefits of involuntary treatment, how best to target its use and how to mitigate its associated harms.

Appendix.

Included studies of involuntary inpatient treatment.

Authors	Year	Country	Study design	Findings
1. Aguglia et al., 2023 (89).	2023	Italy	Re A cross-sectional semi-structured survey administered to all patients (N = 799) consecutively admitted to an Italian hospital over three years (2019–2021).	Mechanical Restraint was more likely among patients admitted involuntarily than voluntarily (79.6% vs. 20.8%, p < .001).
2. Andersen et al., 2016 (77).	2016	Denmark	Retrospective case-control study of coercion in inpatient environment.	The risk of forced measures/coercion being applied was significantly higher if patients were involuntarily admitted (OR = 6.4)
3. Arcuni et al., 1989 (35).	1989	US	Retrospective case note review of 20 involuntarily admitted patients and 20 voluntary admitted patients from one unit.	The mean daily dosage of neuroleptic medication was statistically significantly higher in the involuntary population. Greater use of restraints and seclusion in the involuntary group. Non-significant longer LOS.
4. Bainbridge et al., 2018 (115).	2018	Ireland	Prospective observational study of 263 people admitted involuntarily in Ireland, assessed during admission and 3 months post admission.	Higher baseline awareness of illness (B = 0.19, p < .001) and older age (B = 0.05, p = .001) were associated with more satisfaction with care at baseline and follow-up. Transition to greater satisfaction with care was associated with improvements in awareness of illness (B = 0.13, p < .001) and in symptoms (B = 0.05, p = .02), as well as older age (B = 0.04, p = .01). Objective coercive experiences were not associated with variation in satisfaction with care.
5. Beattie et al., 2009 (52).	2009	Ireland	Cross-sectional study inviting participation from people who had experienced psychosis and had been discharged from an inpatient unit within the past 12 months, 47 participants recruited.	Factors related to admission, including perceived coercion and involuntary treatment failed to act as significant predictor variables for PTSD.
6. Bilanakis et al., 2010 (78).	2010	Greece	A retrospective chart review of 282 admissions examining for coercive physical practices.	Patients subjected to seclusion and restraint were more likely to have been involuntarily admitted (60% vs 5%, p = .000)
7. Bindman et al., 2005 (11).	2005	UK	A cohort of 100 consecutively admitted subjects were interviewed at admission and before discharge, and were followed prospectively for 10 months.	Of involuntary patients 15% did not know they were involuntary. Perceived coercion was not a significant independent predictor of any of the outcome variables at follow-up.
8. Bird et al., 2020 (106).	2020	Belgium Germany Italy Poland UK	A cross sectional study conducted in inpatient units across five different European countries, assessing satisfaction with care among 7302 patients and the association with clinical and demographic factors.	Involuntary admission associated with reduced levels of patient satisfaction on the Client Assessment of Treatment Scale (CAT).
9. Bø et al., 2016 (107).	2016	Norway	A pragmatic, randomised trial comparing second generation antipsychotics (SGAs) in the treatment of psychosis collected responses to the UKU-ConSat at discharge/follow-up (between 6 and 11 weeks after admittance if not discharged earlier) from 104 patients.	Involuntary patients were less satisfied with the information provided to them but other measures of satisfaction were not statistically significant.
10. Bonsack et al., 2005 (12).	2005	Switzerland	A cross-sectional survey among 87 inpatients of a Swiss psychiatric hospital to assess their subjective view of admission with emphasis on legal status, perceived coercion and need for hospitalisation.	A third of voluntary patients felt that their hospital admission was after all not so voluntary (29%), or even involuntary (4%). In contrast, 44% of committed patients felt a posteriori that their hospital admission was more or less voluntary (29%) or clearly voluntary (15%). 11% of voluntary patients felt they had not improved while 40% of committed patients reported a subjective lack of improvement (χ2 = 9, df = 2, p ≤ .01.)
11. Boydell et al., 2014 (128).	2014	UK	Review of data collected as part of a large study, with a particular focus on ethnicity, of all first-episode psychosis cases from South London, Nottingham and Bristol presenting between 1997 and 1999, the AESOP (Aetiology and Ethnicity in Schizophrenia and Other Psychoses) study. The proband and nearest relative (or partner/friend) were interviewed soon after the onset of the psychosis.	Caregivers of patients who had been admitted under compulsion were significantly more likely to report burden in terms of having ‘problems with services’.
12. Carr et al., 2008 (90).	2008	Australia	Data on acute adverse events prospectively collected from 11 hospitals and >5500 admissions	Involuntary status associated with longer inpatient admission (2.56 days longer) and being involved in less serious aggressive incidents (AOR = 2.31).
13. Castelpietra et al., 2021 (41).	2021	US	Observational longitudinal study comparing 19 compulsory admissions and 83 voluntary admissions consecutively admitted to a General Hospital Psychiatric Unit of Udine, Italy, and followed up for six months by community mental health services. All 102 patients were assessed using 5 psychometric tests at admission, discharge, and 6 months post discharge.	An improvement in all scales was seen in both compulsory and voluntary groups and at 6 months post discharge no difference was evident between the two groups.
14. Chang et al., 2013 (40).	2013	Brazil	Retrospective cohort study examining adult admission data collected from a university hospital in Brazil.	No differences in the duration of hospitalisation and the attendance at first appointment after discharge.
15. Crisanti et al., 1999 (100).	1999	Germany	A retrospective cohort design with a maximum 9-year variable follow-up. A multistage sampling procedure was used to generate the sample, which consisted of 1064 involuntarily admitted patients and 1078 voluntarily admitted patients.	107 deaths identified, 58 involuntary and 49 voluntary [chi 2 (1) = 0.9255, p = .336]. No significant differences were observed between the cohorts when survival analysis was used to examine survival experiences in the community.
16. Danielsen et al., 2019 (79).	2019	Denmark	Supervised machine learning algorithms were trained on a randomly selected subset of clinical notes from electronic health records from the Central Denmark Region and data from the Danish Health Registers from 5050 patients admitted to a psychiatric department in the period from 2011 to 2015.	Involuntary status was the strongest predictor of mechanical restraint use.
17. de Haan et al., 2007 (38).	2007	The Netherlands	Prospective study of 119 consecutively admitted patients suffering from a first episode of schizophrenia or related disorders.	Involuntary admision associated with medication non-adherence 5 years after admission (p .02).
18. Del Favero et al., 2020 (70).	2020	Italy	Observational single-center retrospective study of all patients (798) aged ≥18 years who were admitted to two psychiatric units in Italy over a 2 year period.	Compulsory index admission and higher education were protective against readmission.
19. Delayahu et al., 2014 (125).	2014	Israel	Retrospective chart review of 24 patient records over a period of five years.	A smaller proportion of patients discharged from involuntary admissions were in remission compared to those discharged from voluntary admission. Nevertheless, involuntary admissions were associated with longer time to next hospitalisation.
20. Dey et al., 2016 (59).	2016	New Zealand	Retrospective database review of rehospitalisation rates and bed days for 451 patients with schizophrenia discharged from three inpatient facilities between July 2009 and December 2011.	Patients whose index admission included compulsory treatment appeared more likely (HR = 1.3, 95% CI = 0.98-1.71, p = .06) to be rehospitalised and spent longer rehospitalised (p = .05).
21. Di Lorenzo et al., 2018 (121).	2018	Italy	Retrospective chart review of all hospitalisations in the Service of Psychiatric Diagnosis and Treatment of a northern Italian town from 1 January 2015 to 31 December 2015.	Involuntary hospitalisation was statistically significantly associated with longer lenght of stay.
22. Draghetti et al., 2022 (72).	2022	Italy	Prospective observational study of all inpatient admissions in an Italian emergency ward, including 390 admissions.	No significant differences were found in terms of drop-outs, transferring, and discharge rates, and mortality rates due to both natural causes and suicides. Factors associated with at least one compulsory readmission were younger age and having had a previous CA (p = .011).
23. Drakonakis et al., 2022 (73).	2022	Greece	A prospective cohort study with a 2-year follow-up period including 544 patients.	Similar improvements in GAF and HoNOS for involuntary and voluntary patients, higher rates of readmission for voluntary patients but higher rates of involuntary readmission for involuntary patients.
24. Færden et al., 2020 (13).	2020	Norway	A prospective study of all patients admitted to a psychiatric ward who was invited to complete the Psychiatric Inpatient Questionnaire (PIPEQ) post-discharge.	Patient satisfaction was significantly less for those perceiving involuntary admission regardless of legal status. 21/70 voluntary patients said their admission was not of their free will, while 24/89 involuntary patients thought the admission was of their free will.
25. Feigon et al., 2003 (60).	2003	US	Retrospective examination of records of 943 patients randomly selected from 14,649 admissions and examined for a 5-yr. period following initial admission.	Involuntary commitment and a longer length of stay at the original admission were associated with a higher rate of readmission.
26. Fennig et al., 1999 (74).	1999	Israel	Retrospective analysis of routinely collected data from all patients in Israel who had a non-forensic first admission between 1978 and 1992 and a diagnosis of schizophrenia. The extent to which the legal status of a first psychiatric admission-voluntary or involuntary-predicted the legal status and number of future admissions was examined.	The legal status of the first admission was not related to the number of readmissions. However, female patients whose first admission was involuntary were 4.1 times more likely to have an involuntary second admission than female patients whose first admission was voluntary; these odds were 3.4 for males.
27. Fiorillo et al., 2012 (31).	2012	11 European countries	A multicentric prospective cohort study was carried out as part of the European evaluation of coercion in psychiatry and harmonisation of best clinical practice – EUNOMIA project in 11 European countries.	Involuntary admission, female gender, poorer global functioning and more positive symptoms were associated with higher levels of perceived coercion at admission.
28. Gardner et al., 1999 (18).	1999	US	Prospective cohort sample of 293 voluntary and 140 involuntary patient consecutive admissions at two hospitals interviewed about their experience.	The majority of involuntary patients did not believe they needed hospitalisation. Coerced patients did not appear to be grateful for the experience of hospitalisation, even if they later concluded that they had needed it.
29. Georgieva I et al., 2012 (80).	2012	The Netherlands	Prospective study of patient factors associated with seclusion among 520 patients.	Involuntary hospitalisation the strongest predictor of seclusion in mulivariate model OR 4.66.
30. Golay et al., 2019 (19).	2019	Switzerland	Observational sample of 152 patients admitted to a psychiatric ward who was interviewed regarding their knowledge of their legal status.	6.6% of voluntarily admitted patients and 30.4% of involuntarily admitted patients reported an erroneous status of admission. 88.2% of voluntarily admitted patients and 44.7% of involuntarily admitted patients felt that they needed hospitalisation during their stay. Levels of perceived coercion at admission and during hospitalisation were mostly predicted by their perceived legal status.
31. Goula et al., 2021 (116)	2021	Greece	Observational cohort study of 100 admitted patients invited to participate in a survey.	The involuntary patients were significantly more satisfied with the conditions of hospitalisation as well as assessing the overall quality of the services provided during their hospitalisation.
32. Graca et al., 2013 (61).	2013	Portugal	Retrospective analysis of routinely collected data for 1,348 consecutively admitted psychiatric inpatients.	A larger proportion of frequent users had compulsory admissions (28% versus 14%, p < .001).
33. Hamann J et al., 2008 (20).	2008	Germany	Semistructured interviews of cohort sample of psychiatrists and inpatients with schizophrenia in an inpatient unit.	Patients who were treated on a voluntary basis reported that they had been involved in reaching the decisions they had reported more often (in 88% of the decisions) than patients treated on an involuntary basis. Involuntary patients reported more decisions that they would have made differently than patients being treated voluntarily (56% vs.31%, p = .001).
34. Hansson et al., 1989 (108).	1989	Sweden	Surveys mailed to all admitted patients from a psychiatric unit 1 year post discharge.	Significant differences in patient satisfaction were found between patients voluntarily admitted and patients compulsorily admitted. The latter showed a lower level of satisfaction in all areas except Treatment Design. 94.6 % of voluntarily admitted patients were generally satisfied, compared to 80.3% of involuntary patients.
35. Hofmann et al., 2022 (42).	2022	Switzerland	Retrospectively extracted clinical data from inpatients treated in an academic hospital in Zurich, Switzerland between January 1, 2013 and December 31, 2019	Compulsorily admitted patients achieved a clinical improvement similar to voluntarily admitted patients in a shorter length of stay. During the 12 months following discharge, those initially voluntarily admitted had a higher readmission rate.
36. Hoge et al., 1997 (14).	1997	US	Observational cohort study of admitted patients from two university hospitals, who were invited to participate in surveys regarding their admission process.	3.3% of voluntary patients and 41.7% of involuntary patients thought deceit was involved in their admission. 21.2% of involuntary patients thought they were voluntary or did not know their status. 3.3% of voluntary patients who thought they were involuntary or did not know.
37. Hoge et al., 1998 (21).	1998	US	Observational cohort study recruiting 433 admitted during single days to two university hospitals.	Higher Perceived Coercion Scale scores were found in involuntary cases when compared with voluntary cases for patient reports, family reports, and clinician reports.
38. Houston et al., 2001 (62).	2001	US	Obervational study of 487 patients admitted to a psychiatric unit between 1986 and 1990.	Based upon overall sample proportions, involuntary patients were significantly over-represented among those who were readmitted within 30 days. Among those who were readmitted within 30 days 85% were originally committed versus only 15% of voluntary patients.
39. Hunt et al., 2009 (94).	2009	UK	A national population-based case-control study of 238 psychiatric patients dying by suicide within 3 months of hospital discharge, matched on date of discharge to 238 living controls.	Patients who were detained for compulsory treatment at last admission, or who were subject to enhanced levels of aftercare, were less likely to die by suicide.
40. Hustoft et al., 2022 (119).	2022	Norway	A multi-centre study of consecutively admitted patients to emergency psychiatric wards over a 3 months period in 2005–06.	As many as 29.7% of the involuntary patients stated that they wanted to be hospitalised.
41. Ivar Iversen et al., 2002 (15).	2002	Norway	All patients aged 18–60 admitted to four acute wards at two Norwegian psychiatric hospitals from October 1998 through November 1999 were invited to participate in a survey, regardless of their legal admission status.	32% of voluntarily admitted patients perceived high levels of coercion, and 41% of involuntarily admitted patients perceived low levels of coercion. Legal status did not significantly predict perceived coercion on either the MacArthur Perceived Coercion Scale or a visual analogue scale (the Coercion Ladder).
42. Jaeger S, et al., 2013 (22).	2013	Germany	A naturalistic observational multi-centre study, in which 290 voluntarily and 84 involuntarily hospitalised patients with schizophrenia or schizoaffective disorder were followed up over a period of 2 years with half-yearly assessments.	Involuntariness of the index-hospitalisation did not have an effect on the development of treatment engagement or medication adherence judged by blood levels in the course of the follow-up period when the models were controlled for sociodemographic variables and clinical history. It was associated, though, with a continuously lower self-rated medication adherence. Moreover, former involuntarily hospitalised patients more often felt coerced in several treatment aspects at the follow-up assessments.
43. Jordan et al., 2020 (103).	2020	US	Data from a longitudinal prospective observational study (the MacArthur Violence Risk Assessment Study) was analysed.	No effect of voluntary versus involuntary legal status on risk for postdischarge suicide attempts (OR = 1.28, |z| = 1.01, p = .313. Patients who perceived their hospitalisation as coercive were significantly more likely to make a postdischarge suicide attempt, even when adjusting for nonrandom assignment of perceived coercion.
44. Kallert et al., 2011 (49).	2011	11 European countries	At study sites in 11 European countries consecutive legally involuntary patients and patients with a legally voluntary admission who however felt coerced, were recruited and assessed by independent researchers within the first week after admission. Symptoms were assessed on the Brief Psychiatric Rating Scale.	In a multivariable analysis, higher baseline symptoms, being unemployed, living alone, repeated hospitalisation, being legally a voluntary patient but feeling coerced, and being initially less satisfied with treatment were all associated with less symptom improvement after one month and, other than initial treatment satisfaction, also after three months.
45. Kaltiala-Heino et al., 1997 (27).	1997	Finland	Interviews and assessments of three series of consecutively admitted psychotic patients during random weeks in autumn 1990, spring 1991, and summer 1992.	No effect of legal status on treatment outcome. Patients who had perceived the index admission especially coercive now showed worse status in Brief Psychiatric Rating Scale than those not feeling coerced, and in Global Assessment Scale they also tended to appear in worse status. They showed no improvement to the first assessment in BPRS and GAS whereas those not feeling coerced had improved.
46. Kan et al., 2007 (99).	2007	Hong Kong	A case-control study based on discharged patients from all psychiatric hospitals/units in Hong Kong in 1997-1999.	Risk factors for suicides were: previous deliberate self-harm (OR = 2.3, 95% CI = 1.07-5.05), admission for deliberate self-harm (OR = 3.2, 95% CI = 1.3-7.8), compulsory admission (OR = 3.1, 95% CI = 1.1-8.7), living alone (OR = 5.8, 95% CI = 1.4-23), work stresses (OR = 5.4, 95% CI = 1.5-18) and being out of contact (OR = 7.9, 95% CI = 1.87-33).
47. Kjellin et al., 2004 (29).	2004	Sweden	At four psychiatric care settings in different parts of Sweden, 138 committed and 144 voluntarily admitted patients were interviewed at admission using the Nordic Admission Interview.	Coercion in psychiatric care, as reported by patients and relatives, was not always legally based, and many of the patients reported they felt violated during the admission process.
48. Kjellin et al., 2006 (28).	2006	Denmark Iceland Norway Finland Sweden	From one to four centres each in Denmark, Iceland, Norway, Finland and Sweden, a total of 426 legally committed and 494 formally voluntarily admitted patients were interviewed within 5 days from admission.	The proportion of committed patients reporting high levels of perceived coercion varied among countries (from 49% in Norway to 100% in Iceland), and in Sweden, only, among centres (from 29 to 90%). No clear variations in this respect were found among voluntary patients.
49. Kjellin et al., 1997 (30).	1997	Sweden	A consecutive sample of 84 committed patients and a random sample of 84 voluntarily admitted patients in psychiatric care in two Swedish counties were studied. The patients were assessed twice by a psychiatrist, at admission and at discharge or after three weeks of care. They were also interviewed by a clinical psychologist at discharge or after three weeks.	Involuntary patients were more likely to report that their autonomy had been violated, and to receive no ethical benefits from admission.
50. Knutzen et al., 2011 (81).	2011	Norway	A two-year retrospective case-control design comprising all restrained patients (N = 375) and a randomly selected control group of no nrestrained patients (N = 374) from three catchment-area-based acute psychiatric wards in Norway.	Use of restraint was predicted by multiple admissions, long inpatient stays, and involuntary admission.
51. Korkeila et al., 2002 (86).	2002	Finland	Retrospective chart review of all civil admissions to the study hospitals of working-aged people during a period of 6 months in 1996.	The individual institutions best predicted the overall use of restrictive interventions, whereas previous commitments and involuntary legal status on admission were factors predicting "heavy use" of these measures.
52. Kortrijk et al., 2010 (47).	2010	The Netherlands	Observational study of routine monitoring of 260 severely mentally ill patients at risk for involuntary admission.	During the observation period, 77 patients (30%) were involuntarily admitted. Relative to patients who were not involuntarily admitted, these patients improved significantly in HoNOS total scores (F = 17,815, df = 1, p < .001) and in motivation for treatment (F = 28.139, df = 1, p < .001). Patients who were not involuntarily admitted had better HoNOS and motivation scores at baseline, but did not improve.
53. Leavey et al., 1997 (109).	1997	UK	Ninety-three patients with psychosis who lived in a defined psychiatric catchment area in North London were recruited over a 12-month period from July 1991 and invited to participate in a survey.	Compulsory detention under the Mental Health Act was also significant in determining low satisfaction for patients and especially for their relatives.
54. Lerner et al., 2010 (122).	2010	Israel	All hospitalisation admissions during a six-month period in Israel were recorded and followed-up for one year.	The variables significantly predicting longer Cumulative LOS were: Jewish ethnicity, a diagnosis of schizophrenia or other functional psychosis, prior hospitalisation, compulsory admission and Northern and Jerusalem districts of hospitalisation (which have a lower admission rate).
55. Levine et al., 2008 (76).	2008	Israel	Retrospective review of first and subsequent admissions for schizophrenia from the complete Israeli national registry of psychiatric admissions for the years 1978 to 1992. The cohort (N = 12,071) was followed through 1996 for additional admissions or death.	Association between initial admission status (involuntary, voluntary or forensic) and subsequent admission status.
56. Levola et al., 2022 (101).	2022	Finland	Retrospective review of national register data on psychiatric hospital admissions and death in Finland.	Involuntary psychiatric care was associated with a 40% increase in risk of suicide (HR = 1.42, 95% CI 1.05–1.94).
57. Lin et al., 2019 (63).	2019	Taiwan	Retrospective 7-year (2007–2013), population-based, cohort study comparing data from 2038 involuntary inpatients with schizophrenia and 8152 matched controls with schizophrenia who initially underwent voluntary admission.	Compared with the voluntary group, the involuntary group was associated with a greater risk of psychiatric readmission [adjusted hazard ratio (AHR) = 1.765; 95% confidence interval (CI) 1.389-2.243; p < .001]. Stratified analyses showed that the involuntary group was associated with a higher risk of subsequent compulsory (AHR = 1.307; 95% CI 1.029-1.661; p < .001) and voluntary (AHR = 1.801; 95% CI 1.417-2.289; p < .001) readmissions compared to the voluntary group.
58. Lin et al., 2019 (63).	2019	Taiwan	Retrospective 7-year (2007–2013), population-based, cohort study comparing data from 2038 involuntary inpatients with schizophrenia and 8152 matched controls with schizophrenia who initially underwent voluntary admission.	The cumulative incidence rate of inpatient suicide was not significantly different between compulsory and voluntary admissions (log-rank test, p = .206).
59. Martinaki et al., 2021 (53).	2021	Greece	Observational cohort study of patients admitted to a Greek hospital who was invited to participate in a survey.	Voluntarily hospitalised patients are more vulnerable to PTSD, due to higher rates of affective disorders.
60. Martínez-Ortega et al., 2012 (64).	2012	Spain	Socio-demographic variables, diagnosis, and the legal status, date and length of admission were collected for 1,722 consecutively admitted psychiatric patients during a period of up to eight years (1998–2005).	After controlling for potential confounding factors, logistic regression showed that being a frequently admitted patient was significantly associated with diagnoses of schizoaffective disorder, personality disorder or schizophrenia; an involuntary commitment at first admission; and younger age.
61. McKenna et al., 1999 (23).	1999	New Zealand	Observational study of consecutively admitted patients to a New Zealand health service.	There was a strong significant difference in comparing the informal and invol- untary sample groups with patient perception of coercion (t = -5.29, p = .000). Involuntary patients have a stronger sense of coercion (M = 3.4, SD = 1.7) than informal patients (M = 1.9, SD = 1.8).
62. Meesters et al., 2016 (105).	2016	The Netherlands	Prospective observational cohort study of patients with schizophrenia or schizoaffective disorder in a psychiatric catchment area in Amsterdam, the Netherlands.	Reduced survival was associated with higher age (HR: 1.10; 95% CI: 1.05–1.16), male gender (HR: 3.94; 95% CI: 1.87–8.31), and having had one or more compulsory admissions in the past (HR: 2.61; 95% CI: 1.46–4.68).
63. Meyer et al., 1999 (54).	1999	Finland	Prospective observational study of 46 patients who were assessed with the Positive and Negative Syndrome Scale (PANSS), the Impact of Event Scale-Revised (IES-R), and the Clinician-Administered PTSD Scale (CAPS) at weeks 1 and 8 after acute psychiatric admission.	Total PANSS score above 63 (median, Md, of each patient's mean total PANSS score at weeks 1 and 8) at week 8 was the only significant risk factor for the development of clinical PTSD. Involuntarily admitted patients were not more traumatised than voluntarily admitted.
64. Morán-Sánchez et al., 2020 (32).	2020	Spain	Cross-sectional study among 107 outpatients with DSM diagnoses of schizophrenia of bipolar disorder using the Control Preference Scale to assess congruence in decision-making experienced and preferred style.	The degree of congruence was lower in patients with previous compulsory admissions. The best predictors of compulsory admissions were not having a regular doctor and the unmatched participation preferences.
65. Moss et al., 2010 (95).	2010	Canada	Observational study of consecutive patients applying to the Consent and Capacity Board in Ontario between 1 January 2004, and 31 March 2007, were identified who had a hearing to challenge their involuntary detention. Population based databases provided information on subsequent deaths, hospitalisation for a psychiatric illness, or emergency department visit for any reason.	Approximately 18% of involuntary detentions were rescinded with subsequent outcomes showing a greater likelihood of emergency department visits within 100 days of discharge in the group whose detention was rescinded compared to the group whose detention was upheld (46% vs. 36%, p = .003). No differences in deaths between the two groups.
66. Munk-Jørgensen et al., 1991 (75).	1991	Denmark	All first admitted patients in 1972 from a catchment area of 582,000 inhabitants aged 15 years or more who were diagnosed as schizophrenic at least once from 1972 until September 1983 (n = 53) were followed-up on average 13 years after first admission.	Involuntary admissions were more frequent in the first half of the follow-up period and were correlated to a previous involuntary admission.
67. O'Callaghan et al., 2022 (82).	2022	Ireland	Observational cohort study of patients admitted to two units in Dublin over a 30 month period.	On the basis of multivariable analyses, seclusion was associated with younger age and involuntary status, while physical restraint was associated with involuntary status.
68. O'Callaghan et al., 2021 (24).	2021	Ireland	Observational cohort study of patients admitted to two units in Dublin over a 30 month period.	Perceived coercion on admission was significantly associated with involuntary status and female gender; perceived negative pressures on admission were significantly associated with involuntary status and positive symptoms of schizophrenia; perceived procedural injustice on admission was significantly associated with fewer negative symptoms, involuntary status, cognitive impairment and female gender; and negative affective reactions to hospitalisation on admission were significantly associated with birth in Ireland and being employed. Total score across these four subscales was significantly associated with involuntary status and positive symptoms, and had borderline significant associations with birth in Ireland, being employed and female gender.
69. O'Donoghue et al., 2015 (70).	2015	Ireland	Prospective observational study in which people admitted involuntarily to the three hospitals over a fourteen month period were invited to participate in the study. To have a comparable number of voluntarily admitted participants, after each involuntary admission, the next voluntarily admitted service user was invited to participate.	The ‘coerced voluntary’ had a score of 4 or above on the MacArthur perceived coercion scale and one year after discharge, they had a better therapeutic relationship compared to involuntarily admitted service users. There was no difference between the coerced voluntary, uncoerced voluntary and involuntary groups in engagement, satisfaction and functioning.
70. Opjordsmoen et al., 2010 (48)	2010	Norway	Prospective observational cohort of consecutively first-admitted, hospitalised patients from a voluntary group (n = 91) with an involuntary group (n = 126), assessing psychopathology and functioning using Positive and Negative Syndrome Scale and Global Assessment of Functioning Scales at baseline, after 3 months and at 2 year follow-up.	Voluntary patients had less psychopathology and better functioning than involuntary patients at baseline. No significant difference as to duration of psychotherapy and medication between groups was found. No significant difference was found as to psychopathology and functioning between voluntarily and involuntarily admitted patients at follow-up.
71. Opsal et al., 2016 (34).	2016	Norway	Observational cohort study in Norway in which patients were invited to fill in the Perceived Coercion Questionnaire.	Scores on the Perceived Coercion Questionnaire showed that patients admitted voluntarily and those admitted involuntarily experienced similar levels of perceived coercion.
72. Paksarian et al., 2014 (56).	2014	UK	Participants (N = 395) in the Suffolk County Mental Health Project, who had been admitted for the first time for a psychotic disorder ten years earlier, were interviewed.	The most commonly reported specific experiences of perceived trauma were involuntary hospitalisation (N = 217, 62%), being put in restraints (N = 142, 40%), and being forced to take medication (N = 130, 37%).
73. Pauselli et al., 2017 (123).	2017	Italy	Retrospective chart review of all admissions to the Psychiatric Inpatient Unit of Santa Maria della Misericordia, Perugia Hospital, Umbria, Italy, from June 2011 to June 2014.	The study sample included 1236 patients. In the final, most parsimonious regression model, five variables independently explained 18 % of variance in LoS: being admitted involuntarily, being admitted for thought disorders, not having a substance-related disorder, having had more than one hospitalisation, and being discharged to a community residential facility.
74. Pérez-Revuelta et al., 2021 (83).	2021	Spain	Cross-sectional study based on a retrospective analysis of 412 mechanical restraint records.	The factors associated with admissions requiring mechanical restraint were involuntary, unscheduled and longer admissions. The best predictor of restraint was involuntary admission (OR = 6.37), followed by the diagnosis of personality disorder (OR = 5.01).
75. Pfiffner et al., 2014 (68).	2014	Germany	Prospective observational study of 374 admitted patients with a diagnosis of schizophrenia or schizoaffective disorder. Follow-up assessments were conducted half-yearly over a 2-year period with measures of PANSS, GAF, sociodemographic data and cognitive functioning.	After adjustment for other relevant covariates, the Cox regression showed that involuntary treatment is a significant risk factor of subsequent rehospitalisation (HR = 1.53; CI = 1.06, 2.19; p = .02).
76. Plunkett et al., 2022 (120).	2022	Ireland	Prospective cohort study recruiting 107 participants aged 18 years or over from two inpatient psychiatric units in Dublin, Ireland over a 30-month period. Interviews consisted of structured, validated assessment tools.	On multi-variable testing, lower self-rated dignity was associated with higher perceived coercion, better insight and more negative symptoms. There was no association between dignity and gender, employment status, marital status, ethnicity, age, admission status, diagnosis, working alliance, positive symptoms or cognition.
77. Priebe et al., 1998 (55).	1998	Germany	Observational cohort study in which all patients with schizophrenia who were treated in the care system within a period of 1 year were asked to participate.	PTSD symptoms were not correlated with reports of involuntary admissions.
78. Rain et al., 2003 (39).	2003	US	Sub-analysis of data generated by the MacArthur Violence Risk Assessment Study, an observational study of patients admitted at 3 hospital sites.	Perceived coercion scores were not associated with treatment adherence.
79. Rane et al., 2012 (65).	2012	India	Retrospective case-note review of cohort of patients admitted voluntarily and involuntarily.	Compared with those admitted voluntarily, those admitted involuntarily tended to be single, middle aged (40–60 years old) and non-Goan; on average they had a significantly longer hospital stay than voluntarily admitted patients.
80. Ranieri et al., 2015 (130).	2015	Ireland	Observational study involving interviews with people admitted to 5 Irish inpatient units and their carers.	Caregivers of involuntarily admitted individuals perceived the service users' admission as less coercive than reported by the service users. Caregivers also perceived a higher level of procedural justice in comparison to the level reported by service users.
81. Ranieri et al., 2017 (129).	2017	Ireland	Observational study involving interviews with people admitted to Irish inpatient units and their carers, taken from the Service Users’ Perspectives of their Admission (SUPA) study9 and the Prospective Evaluation of the Operation and Effects of the Mental Health Act 2001 from the Viewpoints of Service Users and Health Professionals study.	The overall level of burden and psychological distress experienced by caregivers did not differ according to the patient's legal status.
82. Reith et al., 2004 (102).	2004	Australia	A prospective cohort study using data-linkage between the Hunter Area Toxicology Service Database and the National Death Index of the Australian Institute of Health and Welfare, from January 1991 to December 2000.	The probability of suicide after 10 years follow-up was 2%. The adjusted hazard ratios (95% CI) for suicide were: 'disorders usually diagnosed in infancy, childhood and adolescence', 5.28 (95% CI = 2.04–13.65): male gender, 4.25 (95% CI = 2.21–8.14); discharge to involuntary psychiatric hospital admission, 3.20 (95% CI = 1.78–5.76); and increasing age, 1.02 (95% CI = 1.01–1.04).
83. Roche et al., 2014 (50).	2014	Ireland	Observational prospective cohort study of all individuals who were admitted involuntarily to 3 psychiatric hospitals, and the next service user admitted voluntarily.	Individuals who are admitted involuntarily, who have a diagnosis of a psychotic disorder, and who report high levels of perceived pressures on admission are more likely to have a poor therapeutic relationship with their consultant psychiatrist.
84. Rosca et al., 2006 (66).	2006	Israel	Retrospective data review of information extracted from the National Psychiatric Case Registry on all patients admitted for the first time during 1991 (N = 2150) and on their follow-up over the next ten years.	Compared with patients admitted voluntarily, those who were admitted involuntarily had a significantly greater number and duration of rehospitalisation’s.
85. Roy et al., 1995 (104).	1995	Canada	Observational study comparing 37 in-patients from an Ontario Provincial Psychiatric Hospital who had committed suicide with 37 age and sex matched in-patient controls.	Significantly more of the suicide victims had made a previous suicide attempt (62.2 v. 35.1%), suffered from schizophrenia (75.7 v. 35.1%), were involuntary at their last admission (70.3 v. 43.2%) and lived alone (70.3 v. 43.2%).
86. Sampogna et al., 2019 (25).	2019	Italy	Observational study of 294 patients were recruited in five Italian psychiatric hospitals and screened with the MacArthur Perceived Coercion Scale to explore the levels of perceived coercion.	On multivariable regression model, being compulsorily admitted (OR: 2.5; 95% CI: 1.3–3.3, p < .000), being male (OR: 0.7; 95% CI: 0.9–1.4; p < .01), being older (OR: 0.03; 95% CI: 0.01–0.06) and less satisfied with received treatments (OR: –0.2; 95% CI: –0.3 to –0.1; p < .05) were all associated with higher levels of perceived coercion, even after controlling for the use of any coercive measure during hospitalisation.
87. Schneeberger et al., 2017 (84).	2017	Germany	Naturalistic observational study analysing the occurrence of aggressive behavior as well as the use of seclusion or restraint in 21 German hospitals.	Restrictive interventions used to control aggression were significantly reduced in open-door hospital settings.
88. Seo et al., 2013 (45).	2013	South Korea	Prospective observational study assessing symptoms and insight at 6 months and 1 year.	Neither coercive measures nor perceived coercion had a significant effect on the change of mental symptoms and that, thus, coercion had little contribution to the declining of symptoms.
89. Setkowski et al., 2016 (67).	2016	The Netherlands	Prospective observational study of admitted patients interviewed twice using the Verona Service Satisfaction Scale and the Birchwood Insight Scale.	Increasing patient satisfaction in the first 2 years was associated with a lower risk of compulsory re-admission in the subsequent follow-up period, but this association proved to be dependent on a history of involuntary admissions in these first two follow-up years.
90. Shah et al., 2009 (96).	2009	UK	An ecological study, over the 19-year period, to examine the relationship between rates of involuntary admissions and general population suicide rates in England and Wales.	There were negative correlations between rates of involuntary admissions and general population suicide rates in both sexes.
91. Shin et al., 2022 (126).	2022	US	Retrospective cohort study of recorded data from 521 patients with psychiatric illnesses hospitalised over 2013–2015.	Court-ordered legal procedures were strongly associated with longer LOS.
92. Shinjo et al., 2017 (124).	2017	Japan	Retrospective cohort study of adult psychiatric inpatients between April 2012 and March 2014 in the Japanese Diagnosis Procedure Combination database.	Older age, lower Global Assessment of Functioning score, involuntary commitment, several psychiatric services, certain other patient factors, academic hospitals, public hospitals, and higher density of psychiatric beds were significantly associated with prolonged lenght of stay.
93. Silva et al., 2020 (69).	2020	Portugal	Retrospective cohort study of the factors associated with length of stay and readmission in Portuguese psychiatric inpatient services during 2002, 2007 and 2012.	Older age, a diagnosis of psychosis, and compulsory admission were associated with higher odds of longer length of stay. Being retired (or others), a diagnosis of psychosis, compulsory admission, and psychiatric service were associated with increased odds of readmission.
94. Silva, et al., 2022 (10).	2022	Portugal	Observational study of patients recruited during admission to 5 hospital sites.	Perceived fairness was the stronger predictor of both satisfaction with treatment (β = .234; p = .022) and satisfaction with decision-making involvement (β = .360; p < .001)
95. Smith et al., 2014 (110).	2014	Ireland	Multi-centre observational study was conducted across three mental health services in Ireland. Service users were interviewed and provided with self-report questionnaires. The Client Satisfaction Questionnaire (CSQ-8) was used to measure treatment satisfaction.	Service users who were admitted involuntarily, who experienced physical coercion and lower levels of procedural justice were less satisfied.
96. Sørgaard et al., 2007 (33).	2007	Norway	Observational study in which surveys of coercion were administered to all admitted patients on two acute wards.	Involuntariness was associated with increased likelihood of feeling excluded from participation in the treatment.
97. Spence et al., 1988 (118).	1988	Australia	Interviews of 100 patients admitted consecutively between September 1983 and June 1984.	Although patients who were involuntarily admitted initially reported unfavourable attitudes, subsequent to admission they had similar opinions regarding their hospitalisation to those of voluntary patients.
98. Steinert et al., 2004 (43).	2004	Germany	Observational study of 88 consecutively admitted patients with schizophrenia and delusional disorders who were assessed with the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning (GAF).	No association with PANSS or GAF and admission status.
99. Stewart et al., 2012 (97).	2012	UK	Retrospective case note analysis.	Diagnosis, formal or voluntary admission, marital status, substance use, health problems and violence were not significantly associated with self-harm or attempted suicide.
100. Strauss et al., 2013 (112).	2013	US	Observational study examining associations between objective and subjective indices of coercive treatments and patients' satisfaction with care in a psychiatric inpatient sample (N = 240)	Lower satisfaction ratings were independently associated with three coercive treatment variables: current involuntary admission, perceived coercion during current admission, and self-reported history of being refused a requested medication.
101. Svindseth et al., 2007 (114).	2007	Norway	Observational study in which 102 patients were interviewed within 48 h after hospitalisation about their experiences of the admission process. The structured Admission Experience Survey questionnaire was used to identify negative events of the admission process. Perceived humiliation was defined by a cut-off on the self-reported Cantrill's Ladder Scale.	Negative events during the admission process were significantly more common among patients with involuntary admission, but were also observed among those voluntary admitted.
102. Svindseth et al., 2010 (44).	2010	Norway	Observational study of 147 patients examined at admission and discharge. The instruments used were the Brief Psychiatric Rating Scale (BPRS), the Narcissistic Personality Inventory-29 (NPI-29), the Hospital Anxiety and Depression Scale (HADS), a combination of questions measuring negative experiences and Cantril's ladder measuring experienced humiliation.	Type and length of admission did not significantly affect the outcome.
103. Svindseth et al., 2013 (113).	2013	Norway	Consecutively admitted patients (N = 186) were interviewed with several validated instruments.	Final multivariate analysis found significant associations between compulsory admission, not being in paid work, high scores on hostility, and on entitlement, and high levels of humiliation.
104. Swartz et al., 2003 (51).	2003	US	Retropsective observational survey of patients and clinicians.	Reluctance to seek outpatient treatment associated with fear of coerced treatment (mandated treatment-related barriers to care) was significantly more likely in subjects with a lifetime history of involuntary hospitalisation, criminal court mandates to seek treatment, and representative payeeship.
105. Taborda et al., 2004 (26).	2004	Brazil	A cross-sectional study carried out during a 12-month period of admissions at a univeristy hospital.	Psychiatric patients (involuntary and voluntary) reached significantly higher scores in all coercion scales than surgical and medical patients. The involuntary psychiatric patients presented statistically significant higher scores in all coercion scales than those of the psychiatric patients who were voluntarily admitted to the hospital.
106. Tseng et al., 2022 (127).	2022	Taiwan	A retrospective cohort study that collected 1 million randomly sampled beneficiaries from a National Health Insurance Database for 2002-2013. It identified and matched 181 patients with involuntary psychiatric admissions (research group) with 724 patients with voluntary psychiatric admissions (control group) through 1:4 propensity-score matching for sex, age, comorbidities, mental disorder category, and index year of diagnosis.	Average annual healthcare costs per person for involuntary psychiatric admissions were 3.94 times higher compared with voluntary admissions. The general linear model demonstrated that average annual medical costs per person per compulsory hospitalisation were 5.8 times that of voluntary hospitalisation.
107. Tunde-Ayinmode et al., 2004 (88).	2004	Australia	A retrospective chart review of all inpatient admissions to an adult acute unit over a 12 month period.	In contrast to patients who were not secluded, those secluded were more likely to be young, admitted involuntarily and with a diagnosis of schizophrenia.
108. Valevski et al., 2007 (71).	2007	Israel	Retrospective review of all the records (1994–2005) of all consecutive admissions (n = 16,016) to one inpatient mental health facility.	The probability of readmission of the court-ordered and psychiatrist-ordered groups were significantly lower than that of voluntarily admitted patients (p < .05).
109. van der Post et al., 2014 (111).	2014	The Netherlands	Observational study examining random sample of 252 from the 2,682 patients who consecutively came into contact with two psychiatric emergency teams in Amsterdam between September 2004 and September 2006.	Low levels of satisfaction seem to be mainly dependent on a history of previous involuntary admission.
110. Wallsten, et al., 2006 (46).	2006	Sweden	Observational study of 233 involuntarily and voluntarily admitted patients were interviewed within 5 days from admission and at discharge or after 3 weeks of care. Outcome was measured as reported by patients and by change in GAF (Global Assessment Scale) scores.	Coercion was not related to outcome.
111. Way et al., 1990 (85).	1990	US	Retrospective observational study comparing demographic and diagnostic characteristics of 657 patients who were secluded or restrained during a four-week period with characteristics of 22,939 patients who were not.	Characteristics associated with high probabilities included age less than 26 years, length of stay from 30 to 365 days, involuntary legal status, female gender, a diagnosis of mental retardation, and residence in a hospital with a high rate of seclusion and restraint.
112. Wheeler et al., 2020 (36)	2020	Australia	A retrospective cohort study of 800 adults discharged from a large metropolitan Australian mental health unit.	Regression analysis found that compared to their voluntary counterparts, individuals treated involuntarily were 2.7 times more likely to be prescribed an antipsychotic at discharge, 8.8 times more likely to be prescribed more than one antipsychotic at discharge and 1.65 times more likely to be prescribed high-dose antipsychotic treatment at discharge.

Note: SGA = second-generation antipsychotics; AESOP = Aetiology and Ethnicity in Schizophrenia and Other Psychoses; PTSD = posttraumatic stress disorder; PANSS = Positive and Negative Syndrome Scale; PIPEQ = Psychiatric Inpatient Questionnaire; IES–R = Impact of Event Scale–Revised; CAPS = Clinician-Administered PTSD Scale; DSM = Diagnostic and Statistical Manual of Mental Disorders; GAF = Global Assessment of Functioning Scale; SUPA = Service Users’ Perspectives of their Admission; CSQ-8 = Client Satisfaction Questionnaire; BPRS = Brief Psychiatric Rating Scale; NPI–29 = Narcissistic Personality Inventory–29; HADS = Hospital Anxiety and Depression Scale; OR = odds ratio; LOS = length of stay; CAT = Client Assessment of Treatment Scale; CI = confidence interval; GAS = Global Assessment Scale; AHR = adjusted hazard ratio; AOR = Adjusted Odds Ratio; HR = Hazard Ratio; CA = Compulsory Admission; HoNOS = Health of the Nation Outcome Scales.

Ethical standards

Declaration of conflicts of interest

Amy Corderoy has declared no conflicts of interest

Steve Kisely has declared no conflicts of interest

Tessa Zirnsak has declared no conflicts of interest

Christopher James Ryan has declared no conflicts of interest

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Disclosure of benefit

This review was funded by the Victorian Government to inform its Independent Review of Compulsory Treatment Criteria and Alignment with Decision-Making Laws. The authors retained full editorial control of the work, which was completed independently of the Review.