Involuntary admission for psychiatric care can be frightening, coercive, and of questionable clinical benefit. However, rates of involuntary admissions have been on the rise for many years (Keown et al., 2018). 

So, how do we turn the tide of rising involuntary admission rates? Developing suitable interventions and updating policy could address some of these issues, but it’s difficult to know how to do this effectively without fully understanding what is driving involuntary admission rates in the first instance. While a large body of work has sought to understand risk factors for involuntary hospitalisation, it has yet to be comprehensively drawn together in a way that can helpfully inform decision-making. 

To help our understanding, Barnett et al. (2019) published a systematic review earlier this year on ethnic variations in involuntary hospitalisation (Ian Cummins blogged about it on The Mental Elf). They found that migrants and certain ethnic groups were more likely to be admitted involuntarily. In this companion paper, published today in The Lancet Psychiatry, Walker et al. (2019) have broadened their scope, and aimed to summarise existing evidence on other clinical and social risk factors for involuntary psychiatric admission. 

Methods

The authors searched for quantitative, peer-reviewed studies that investigated risk factors for involuntary hospitalisation, with either voluntarily hospitalised or source population comparison groups. The focus was on adult samples, excluding those with a mean age of <18 years.

The authors searched four databases from January 1983, the year that the UK Mental Health Act was enacted, (although they included studies from non-UK countries, and accordingly did not restrict their search by language) to May 2018. Their database search encompassed terms relating to mental health, involuntary hospitalisation, and a range of potential risk factors for involuntary hospitalisation. Reference lists were also searched.

The authors conducted meta-analyses for the association between involuntary hospitalisation and gender, diagnosis, employment, housing status, relationship status, and previous involuntary hospitalisation. In a sensitivity analysis, they re-conducted these analyses limited to studies of high quality. Finally, they performed a narrative synthesis of factors which could not be included in the meta-analyses due to inconsistent or infrequent reporting.

Results

The authors identified 6,728 studies and screened 195 full-texts of which 77 were eligible for inclusion. Studies were captured mainly from a range of high-income countries, 4 from middle-income countries, and comprised just under a million psychiatric inpatients, of whom 23% were hospitalised involuntarily.

Results from meta-analyses indicated that the following characteristics were positively associated with involuntary hospitalisation:

• Male gender 
• Unemployment 
• Receiving welfare benefits 
• Renting (as compared to being a home-owner) 
• Being single 
• Having been previously married 
• Psychosis 
• Bipolar affective disorder 
• Organic disorder 
• Previous involuntary hospitalisation 

Psychosis and previous involuntary hospitalisation were the strongest risk factors, doubling the odds of involuntary hospitalisation (Odds Ratios >2.0).

Meanwhile, a range of diagnoses (depression, mood disorder, anxiety, personality disorder, and neurosis) were associated with voluntary, rather than involuntary, hospitalisation. Only some of these associations remained statistically significant after excluding moderate and low quality studies.

The narrative synthesis drew together evidence on a range of other possible risk factors for involuntary hospitalisation. The inconsistency of these findings was evident, and the methods by which the included studies measured these factors was sometimes unclear. However, these findings were suggestive of roles for positive psychotic symptoms, lack of insight, poor treatment compliance, perceived risk to others, police involvement in admission, issues around social support and area-level deprivation in predicting involuntary hospitalisation. 

Conclusions

The authors concluded that the risk factors most strongly associated with involuntary hospitalisation are psychosis and previous involuntary hospitalisation. The association with psychosis is perhaps unsurprising, as it is a severe and sometimes debilitating mental illness. The association with previous involuntary hospitalisation, meanwhile, could go some way to explaining why involuntary hospitalisation rates are accelerating. Other demographic, economic, social and clinical risk factors were also identified. However, the authors acknowledge that the pathways and mechanisms by which the various factors increase involuntary hospitalisation risk remain unclear. 

Strengths and limitations

This meta-analysis was appropriately conducted, followed a comprehensive search strategy, and successfully captured a large number of relevant studies on an international scale. 

However, some limitations of the study were as follows:

• The quality of included studies varied, with only 22 studies rated as high quality, limiting the robustness of the findings;
• Only unadjusted data were used in the meta-analyses, such that the reported associations may not represent independent and direct relationships;
• There were no studies from low-income countries, potentially due to the focus on peer-reviewed, published research;
• There was no analysis looking at the differences between high- and middle-income countries, which might differ significantly in different healthcare systems;
• There was high heterogeneity in the results, which remains unexplained;
• The authors were unable to investigate the interplay between risk factors, or to explore mechanisms (including possible moderators and mediators) in the observed associations.

Implications for practice

This work is timely, and sorely needed in light of rising involuntary admission rates and the recent review of the UK’s Mental Health Act. In identifying social and clinical risk factors for involuntary hospitalisation, this work tentatively highlights priority groups who could benefit from intervention before their mental health deteriorates to the point that involuntary admission becomes the only viable option. Targeting interventions in this way could reduce the need for involuntary admission, a restrictive and coercive approach to care that ideally should be used sparingly. 

However, this work also highlights gaps in the literature which need to be better understood before the findings can realistically shape policy and practice. Specifically, working with clinicians, patients and carers to understand the mechanisms causing certain groups to be at greater risk of involuntary hospitalisation would be beneficial. These mechanisms may operate at multiple levels. For instance, some service-level procedural aspects of the hospitalisation process might increase the risk for involuntary admission, and policy and austerity-related cuts to services may also play a role in how and why certain groups are at greater risk of involuntary hospitalisation. These issues are yet to be fully understood and should be a priority for future work.

Conflicts of interest

Alice Wickersham had no involvement in this research. She has previously conducted separate work on predictors of involuntary hospitalisation with Dr Bryn Lloyd-Evans (a co-author on this work) at University College London (Wickersham et al., 2019). She receives funding from the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. The views expressed are those of the author and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Links

Primary paper

Walker S, Mackay E, Barnett P, Sheridan Rains L, Leverton M, Dalton-Locke C, Trevillion K, Lloyd-Evans B, Johnson S. (2019) Clinical and social factors associated with increased risk for involuntary psychiatric hospitalisation: a systematic review, meta-analysis, and narrative synthesis. The Lancet Psychiatry Open Access Published: 22 November 2019 DOI: https://doi.org/10.1016/S2215-0366(19)30406-7

Other references

Barnett P, Mackay E, Matthews H. et al (2019) Ethnic variations in compulsory detention under the Mental Health Act: a systematic review and meta-analysis of international data. The Lancet Psychiatry 2019 6(4) 305-317.

Compulsory detention under the Mental Health Act: significantly more likely if you come from a BAME or migrant group

Keown P, Murphy H, McKenna D. et al (2018) Changes in the use of the Mental Health Act 1983 in England 1984/85 to 2015/16. The British Journal of Psychiatry 2018 213(4) 595-599. [PubMed abstract]

Wickersham A, Nairi S, Jones R. et al (2019) The Mental Health Act Assessment Process and Risk Factors for Compulsory Admission to Psychiatric Hospital: A Mixed Methods Study. The British Journal of Social Work bcz037. [Abstract]

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