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Gender differences in reoffending after discharge from medium-secure units

National cohort study in England and Wales

Published online by Cambridge University Press:  02 January 2018

Anthony Maden*
Affiliation:
Institute of Psychiatry, London
Petros Skapinakis
Affiliation:
Departments of Psychiatry, University of Bristol, UK and University of Ioannina School of Medicine, Greece
Glyn Lewis
Affiliation:
Department of Psychiatry, University of Bristol, Bristol
Fiona Scott
Affiliation:
Institute of Psychiatry, London
Rachel Burnett
Affiliation:
Drugs Analysis and Research, Home Office, London
Elizabeth Jamieson
Affiliation:
Broadmoor Hospital, West London Mental Health Trust, Crowthorne, UK
*
Professor Anthony Maden, Department of Forensic Psychiatry, Academic Centre, West London Mental Health NHS Trust, Southall, Middlesex UB1 3EU, UK. Email: a.maden@ic.ac.uk
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Abstract

Background

Previous research has shown that there are gender differences in reoffending after discharge from medium-secure units, but these have not been adequately explained.

Aims

To investigate gender differences in reoffending after discharge from medium-secure psychiatric units.

Method

All people discharged from medium-secure units in England and Wales between April 1997 and March 1998 were followed up for 1 year (n=959; 12% women). Reoffending was estimated by collecting reconviction data from the Home Office's Offenders' Index or from files at the mental health unit up to 2 years after discharge.

Results

Women were less likely than men to be reconvicted within 2 years of discharge (9% v. 16%, OR=0.49, 95% CI 0.25 – 0.98). Adjustments for history of self-harm, drug or alcohol problems and previous offending substantially reduced the gender difference. In the full model the OR was 0.97 (95% CI 0.45–2.12).

Conclusions

Some or all of the gender differences in reoffending between men and women are explained by self-harm, alcohol and drug problems and previous criminal history.

Type
Papers
Copyright
Copyright © 2006 The Royal College of Psychiatrists 

Previous studies of psychiatric patients discharged from medium-secure psychiatric units have suggested that women are less likely to reoffend after discharge compared with men (Reference Coid, Kahtan and GaultCoid et al, 2000; Reference Edwards, Steed and MurrayEdwards et al, 2002). However, results have been inconclusive because of the comparatively small numbers of women. Lower rates may be owing to the confounding effect of variables from psychiatric or forensic history that are known to differ between men and women, such as a history of self-harm (Reference Hawton, Hall and SimkinHawton et al, 2003), physical and sexual abuse (Reference Edwards, Holden and FelittiEdwards et al, 2003), drug or alcohol problems (Reference Farrell, Howes and BebbingtonFarrell et al, 2001) and previous criminal history (Reference Maden, Scott and BurnettMaden et al, 2004). It is important to know whether these variables explain the gender differences in reoffending because this may help to identify patients with lower or higher risk for reoffending.

In a previous paper (Reference Maden, Scott and BurnettMaden et al, 2004) we examined the incidence and risk factors for reoffending in the whole sample. This paper examines data from the same national cohort study to see whether differences in reoffending between men and women exist and if any differences persist after having taken into account the possible confounding factors.

METHOD

Description of the data-set

We used data from the Pathways out of Medium Security study commissioned by the Department of Health (Reference Maden, Scott and BurnettMaden et al, 2004). This study included all individuals (n=959) discharged from medium-secure units in England and Wales between 1 April 1997 and 31 March 1998: 843 men (88%) and 116 women (12%). The sample was drawn from 34 units, 28 within the National Health Service (NHS) and 6 independent units. Further details about the aims and method of the original study are available on request from the authors.

Ethical approval for the main study was obtained from South Thames Medical Research Ethics Committee.

Measures

Socio-demographic and clinical variables

Socio-demographic variables and clinical characteristics of the sample were obtained from the patient notes. We collected information on the following variables: age at admission, source of referral, main diagnosis, history of previous admissions to psychiatric hospital, history of physical or sexual abuse during childhood/adolescence, history of self-harm, history of drug or alcohol problems.

Follow-up data

Follow-up location data, including readmission to a psychiatric hospital, were collected for a period of 12 months after discharge or transfer by writing to the consultant who took over care when the person was discharged or transferred. When patients had been transferred to other hospitals, data were collected from the receiving hospital's medical records department.

Forensic data

Background data in relation to the index offence were collected from the medical records department at each unit. We also recorded the legal status of the admission (voluntary or involuntary) and the number of previous convictions. Reoffending was assessed by collecting information on reconvictions from the Offenders' Index at the Home Office. Data collection time was extended to 2 years for reconviction data because some offences may take many months to go to a court, and then there is a further delay between conviction in a court and recording of this information in the index. However, less-serious offences committed by people who were not sent to court were not recorded. In addition, all convictions that appeared in the Index the first 6 months after discharge were manually checked to ensure that they were referring to new offences committed after discharge and not to the index offence.

Data analysis

All data analyses were conducted using Stata version 7.0 for Windows. A non-parametric non-parametric kappa sample test for the equality of medians evaluated differences in the age at admission and length of stay between women and men. Pearson's χ2 test was used to test for gender differences in the various admission, clinical and forensic variables. The association between gender and reconviction was estimated with a series of logistic regression models using the logit command in Stata. We used the robust option of the logit command combined with the cluster option, to take into account the clustering of the observations within the medium-secure units. We used reconviction at either the first or the second year (Yes/No) as the dependent variable. Crude odds ratios (with 95% confidence intervals) were first obtained for gender; then we entered into the model age and history of self-harm, physical and sexual abuse, alcohol- and drug-related problems and the number of previous convictions. A final model adjusted for all these variables.

RESULTS

Demographic and admission characteristics

Table 1 shows gender differences in admission characteristics and other clinical variables. Women had higher historical levels of self-reported physical and sexual abuse and much higher levels of self-harm than men. Women, however, were less likely than men to have a drug problem and possibly less likely to have problems with alcohol, although the latter did not reach statistical significance. Women were more likely than men to be admitted with a personality disorder and were more likely to have had previous psychiatric treatment. No difference was found between men and women in terms of re-admission to any psychiatric hospital over follow-up.

Table 1 Gender differences in admission characteristics, clinical variables and clinical course of 959 patients discharged from medium-secure units

Women Men P
n % n %
Age at admission, years: median (range) 32 (17–70) 32 (16–70) 0.35 1
Length of stay, days: median (range) 259 (7–2619) 206 (7–3501) 0.09 1
Diagnosis on discharge
   Schizophrenia 60 52 575 68 <0.01 2
   Personality disorder 34 29 79 10
   Depression–neurosis 17 15 103 12
   Other 5 4 84 10
Previous psychiatric treatment
   Yes 108 93 725 87 0.065 2
   No 8 7 107 13
History of physical childhood abuse
   Yes 31 28 155 19 0.025 2
   No 79 72 658 81
History of sexual abuse
   Yes 46 41 88 11 <0.01 2
   No 65 59 723 89
History of self-harm
   Yes 88 78 309 38 <0.01 2
   No 25 22 500 62
Drug problem
   Yes 40 35 428 53 <0.01 2
   No 75 65 379 47
Alcohol problem
   Yes 40 35 341 42 0.12 2
   No 76 65 472 58
Readmission to hospital 3 (n=549)
   Yes 24 27 131 21 0.24 2
   No 65 73 480 79

1. Non-parametric kappa sample test for equality of medians; χ2 P corrected for continuity

2. Pearson's χ2

3. At 12 months after discharge. Patients who spent all of their time in hospital units (n=251) or could not be traced (n=159) were excluded

Forensic characteristics

Table 2 shows details of gender differences in various forensic variables. The forensic profile of men differed significantly from that of women. Men were more likely to be referred from prison, and the index offence was more likely to concern property or be of a sexual nature. Men were also more likely to have two or more previous convictions and/or previous prison sentences.

Table 2 Gender differences in forensic-related variables of 959 patients discharged from medium-secure units

Women Men P
n % n %
Admission source
   High security 17 15 121 14 <0.05 1
   Other hospital 44 38 197 23
   Prison 39 34 406 48
   Community 16 14 117 14
Legal section
   Voluntary 10 9 39 5 <0.01 1
   Civil 47 41 235 28
   Criminal 57 50 560 67
Discharge placement 2
   High-security/medium-security/locked ward 33 28 211 25
   Open ward/general hospital unit 25 22 166 20 0.33 1
   Prison 8 7 115 14
   Community 50 43 351 42
Index offence
   None 30 26 118 14 <0.01 1
   Violent 49 42 409 49
   Property 26 22 65 8
   Sexual 0 0 70 8
   Other 11 10 181 22
Number of previous convictions
   0 or 1 73 63 297 35 <0.01 1
   2 or more 43 37 546 65
Number of previous prison sentences
   0 90 78 404 48 <0.01 1
   1 14 12 150 18
   2 or more 12 10 289 34

1. Pearson's χ2

2. Discharge placement after first admission

Association between reconviction and gender

Table 3 shows that women were less likely to be reconvicted compared with men and the crude OR was 0.49 (95% CI 0.25-0.98), that is women were half as likely to be reconvicted compared with men. We hypothesised that a number of variables would reduce the gender differences in reconviction, and these models are also presented in Table 3. Adjustment for self-harm and number of previous convictions had the strongest effect. In the final model, adjustment for all variables reduced significantly the gender differences in reconviction (OR 0.97, 95% CI 0.45-2.12). In this model significant independent predictors of reconviction were age, self-harm, history of drug problems and number of previous convictions.

Table 3 Odds ratios for reconviction in 116 women compared with 843 men discharged from medium secure units

Variable Reconvicted in 2 years
n (%) OR (95% CI)
Gender
   Men 135 (16)
   Women 10 (9)
Association between reconviction and gender 1
Crude
   Men 1.00
   Women 0.49 (0.25–0.98)
Adjusted
   Model 1: age+previous sexual and physical abuse
      Men 1.00
      Women 0.47 (0.22–0.97)
   Model 2: age+self-harm
      Men 1.00
      Women 0.62 (0.31–1.25)
   Model 3: age+any drug problems+any alcohol problems
      Men 1.00
      Women 0.55 (0.27–1.13)
   Model 4: age+number of previous convictions
      Men 1.00
      Women 0.64 (0.32–1.29)
   Model 5: age+all variables (in models 1–4) 2
      Men 1.00
      Women 0.97 (0.45–2.12)

1. From logistic regression models

2. In the final model significant odds ratios were found for age (0.93, 95% CI 0.91–0.96), self-harm (0.45, 95% CI 0.30–0.68), history of drug problems (2.81, 95% CI 1.66–4.77) and number of previous convictions (4.46, 95% CI 2.60–7.66 for 2 or more convictions v. 0 or 1)

DISCUSSION

Summary of main findings

This study found that women were less likely to be reconvicted than men, but adjustment for a number of variables substantially reduced the gender difference. Logistic regression analysis showed that the gender difference in reconviction was partly explained by the increased level of self-harm in women, together with less previous offending and reduced drug problems in comparison with men. This study also found significant univariate differences between men and women in a number of demographic, clinical and forensic variables, with women being less criminal and more likely to have a past psychiatric history than men.

Comparison with other studies

One of the key findings from the literature review on women and secure psychiatric services (Reference Lart, Payne and BeaumontLart et al, 1999) was that, although women make up less than one-fifth of the population in secure settings in Britain, they are a heterogeneous group, with a wide range of ages and personal, psychiatric and forensic histories. This was found to be the case in this study. It was also observed in the 1999 review that women in secure psychiatric services have a different pattern of diagnosis compared with men; in particular, in the medium-secure services they are more likely to be diagnosed as having a borderline personality disorder than their male counterparts. Again, this was confirmed in our study.

Lart et al's (Reference Lart, Payne and Beaumont1999) review notes the absence of recent outcome studies including women. In high-secure hospital samples, Buchanan (Reference Buchanan1998) found that gender exerted no independent effect, and Jamieson & Taylor (Reference Jamieson and Taylor2004) also showed that there was no statistically significant difference between men and women in the proportion of each reconvicted.

Self-harm and physical or sexual abuse

In terms of levels of self-harm and abuse, there are few studies with which to compare our data as there is even less clinical detail available on women in medium security than on women in high security. Bland et al (Reference Bland, Mezey and Dolan1999) described 87 women in Broadmoor in 1994 and found that nearly 70% had a confirmed or suspected history of childhood sexual abuse and 94% had a history of self-harm. Heads et al (Reference Heads, Taylor and Leese1997) found that for women with schizophrenia in special hospitals, rates of childhood sexual and physical abuse were significantly higher than for their male counterparts. A history of self-harm and sexual abuse is more likely in women (Reference Lart, Payne and BeaumontLart et al, 1999). Histories of early physical or sexual abuse are particularly common in adults with a diagnosis of borderline personality disorder, and may represent a final common pathway for future impulsive and aggressive offending behaviour (Reference Ogata, Silk and GoodrichOgata et al, 1990; Reference Shearer, Peters and QuaytmanShearer et al, 1990). A compulsion to repeat early trauma may be a manifestation of the re-experiencing phenomena of post-traumatic stress disorder (Reference Deblinger, McLeen and AtkinsDeblinger et al, 1989). Physical abuse and sexual abuse may increase the risk of violence against others, whereas self-harm is violence against one's self and may lower the risk for violence against others. Self-harm has been shown to be associated with a lower risk of reconviction (Reference Maden, Scott and BurnettMaden et al, 2004), whereas a history of sexual abuse has been shown to be associated with a higher risk (Reference Maden, Scott and BurnettMaden et al, 2004).

Alcohol and drug problems

Further, alcohol and drug problems are more common in men and substance misuse has been shown to be associated with an increased risk of reconviction (Reference Maden, Scott and BurnettMaden et al, 2004; Reference Scott, Whyte and BurnettScott et al, 2004). Bland et al (Reference Bland, Mezey and Dolan1999) found that 38% of their high-secure hospital sample had an alcohol problem and 37% had a drug problem, levels very similar to those found in our study. There is a well-established link between substance misuse and higher rates of violence by people with major mental illness (Reference Arseneault, Moffitt and CaspiArseneault et al, 2000). In a medium-secure hospital sample, Baxter et al (Reference Baxter, Rabe-Hesketh and Parrott1999) found that comorbidity, with conduct disorder or problem alcohol use, doubled reoffending compared with schizophrenia alone, whereas young age or polydrug use or conduct disorder increased reconviction rates by factors between 2 and 3.

Previous convictions

It has been shown that the strongest predictor of reoffending is the number of previous convictions (Reference BowdenBowden, 1981; Reference Black, Gunn and FarringtonBlack, 1982) and the current study confirmed that. In our own study women appear to have a lower risk of being reconvicted because they tend to less often have a history of previous convictions or of drug problems, and more often have a history of self-harm.

Limitations of the study

The findings of the present study should be considered in the context of the following limitations. First, we were not able to record all types of new offences but only those that led to conviction. Therefore our results cannot be applied to people committing minor offences. This may underestimate the real impact of antisocial behaviour in both men and women. Second, data on reconviction were only obtained from the Offender's Index at the Home Office and this will be inaccurate. The interval between committing an offence and being convicted of it in a court is often many months (especially in the case of those with mental illness), and there is further delay between conviction in a court and recording of this information in the Index. In order to minimise this misclassification, we extended the period of data collection for 2 years regarding reconviction. In addition, all convictions that appeared in the Index within the first 6 months of discharge were manually checked, to ensure that they were referring to new offences committed after discharge and not to the index offence. For practical reasons, we were not able to collect information from other sources such as the national police computer records. In any case, we think that any misclassification would be more likely to bias the results towards the null value, i.e. to further reduce the gender difference in reoffending. Third, medical records, which were usually kept on the units themselves, were the main source of information related to the index admission. They provided details of demography, medical and offending history, source of referral, reason for referral, diagnosis and destination on discharge. Since the information was not collected for the purposes of this particular study, a degree of measurement bias is inevitable, particularly regarding information on self-harm, physical and sexual abuse and drug and alcohol use. If this bias was not random it could influence the results in either direction. Last, even in this large cohort of 959 patients, the number of women was relatively small and the power of the study may have been compromised.

The government is taking a wide-ranging approach to tackling the inequalities that affect women. The Department of Health's (2002) publication Women's Mental Health: into the Mainstream points out in regard to secure and forensic services that there are differences in the social and offending profiles of women and men, their experience of mental ill health, their patterns of behaviour, and their care and treatment needs. Our study highlights these differences and shows that it is possible to use a number of clinical and forensic variables to assess the risk of future offences in individuals discharged from medium-secure units in the UK. Future studies should try to address whether interventions aimed at reducing the impact of self-harm or abuse in women and of alcohol or drug problems in men could lower the risk of reoffending.

Footnotes

Declaration of interest

None.

References

Arseneault, L., Moffitt, T. E., Caspi, A., et al (2000) Mental disorders and violence in a total birth cohort: results from the Dunedin Study. Archives of General Psychiatry, 57, 979986.CrossRefGoogle Scholar
Baxter, R., Rabe-Hesketh, S. & Parrott, J. (1999) Characteristics, needs and re-offending in a group of patients with schizophrenia formerly treated in medium security. Journal of Forensic Psychiatry, 10, 6983.CrossRefGoogle Scholar
Black, D. A. (1982) A 5-year follow-up study of male patients discharged from Broadmoor Hospital. In Abnormal Offenders, Delinquency and the Criminal Justice System (ed. Gunn, J. & Farrington, D. P.). London: John Wiley.Google Scholar
Bland, J., Mezey, G. & Dolan, B. (1999) Special women, special needs: a descriptive study of female special hospital patients. Journal of Forensic Psychiatry, 10, 3445.CrossRefGoogle Scholar
Bowden, P. (1981) What happens to patients released from the special hospitals? British Journal of Psychiatry, 138, 340345.Google Scholar
Buchanan, A. (1998) Criminal conviction after discharge from special (high security) hospital. Incidence in the first 10 years. British Journal of Psychiatry, 172, 472476.Google Scholar
Coid, J., Kahtan, N., Gault, S., et al (2000) Women admitted to secure forensic psychiatric services: I. Comparison of men and women. Journal of Forensic Psychiatry, 11, 275295.Google Scholar
Deblinger, E., McLeen, S. V., Atkins, M. S., et al (1989) Posttraumatic stress in sexually abused, physically abused and non-abused children. Child Abuse and Neglect, 13, 403408.CrossRefGoogle Scholar
Department of Health (2002) Women's Mental Health: Into the Mainstream – Strategic Development of Mental Health Care for Women. London: Department of Health.Google Scholar
Edwards, J., Steed, P. & Murray, K. (2002) Clinical and forensic outcome 2 years and 5 years after admission to a medium-secure unit. Journal of Forensic Psychiatry, 13, 6887.CrossRefGoogle Scholar
Edwards, V. J., Holden, G. W., Felitti, V. J., et al (2003) Relationship between multiple forms of childhood maltreatment and adult mental health in community respondents: results from the adverse childhood experiences study. American Journal of Psychiatry, 160, 14531460.CrossRefGoogle ScholarPubMed
Farrell, M., Howes, S., Bebbington, P., et al (2001) Nicotine, alcohol and drug dependence and psychiatric comorbidity. Results of a national household survey. British Journal of Psychiatry, 179, 432437.Google Scholar
Hawton, K., Hall, S., Simkin, S., et al (2003) Deliberate self-harm in adolescents: a study of characteristics and trends in Oxford, 1990–2000. Journal of Child Psychology and Psychiatry, 44, 11911198.CrossRefGoogle ScholarPubMed
Heads, T. C., Taylor, P. J. & Leese, M. (1997) Childhood experiences of patients with schizophrenia and a history of violence: a special hospital sample. Criminal Behaviour and Mental Health, 7, 117130.Google Scholar
Jamieson, E. & Taylor, P. J., (2004) A re-conviction study of special (high security) hospital patients. British Journal of Criminology, 44, 783802.CrossRefGoogle Scholar
Lart, R., Payne, S., Beaumont, B., et al (1999) Women and Secure Psychiatric Services. A Literature Review. NHS Centre for Reviews and Dissemination (CRD Report no 14). York: University of York.Google Scholar
Maden, A., Scott, F., Burnett, R., et al (2004) Offending in psychiatric patients after discharge from medium secure units: prospective national cohort study. BMJ, 328, 1534.CrossRefGoogle Scholar
Ogata, S. N., Silk, K. R. & Goodrich, S., et al (1990) Childhood sexual and physical abuse in adult patients with borderline personality disorder. American Journal of Psychiatry, 147, 10081013.Google Scholar
Scott, F., Whyte, S., Burnett, R., et al (2004) A national survey of substance misuse and treatment outcome in psychiatric patients in medium security. Journal of Forensic Psychiatry and Psychology, 15, 595605.CrossRefGoogle Scholar
Shearer, S. L., Peters, C. P., Quaytman, M. S., et al (1990) Frequency and correlates of childhood sexual and physical abuse histories in adult female borderline inpatients. American Journal of Psychiatry, 147, 214216.Google Scholar
Figure 0

Table 1 Gender differences in admission characteristics, clinical variables and clinical course of 959 patients discharged from medium-secure units

Figure 1

Table 2 Gender differences in forensic-related variables of 959 patients discharged from medium-secure units

Figure 2

Table 3 Odds ratios for reconviction in 116 women compared with 843 men discharged from medium secure units

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