Self-harm and the prison environment (SHAPE): pilot cohort study
Research type
Research Study
Full title
Self-harm and the prison environment (SHAPE): a pilot prospective cohort study examining the effect of various prison-environmental factors on self-harm behaviour amongst imprisoned men, to inform the design of a future prospective cohort study and assess the feasibility of testing a risk stratification tool
IRAS ID
306528
Contact name
Thomas Stephenson
Contact email
Sponsor organisation
King's College, London
Clinicaltrials.gov Identifier
N/A, N/A
Duration of Study in the UK
0 years, 10 months, 1 days
Research summary
Research Summary
Self-harm in prisons is a major public health issue and significant risk factor for subsequent suicide. Existing research has identified a small number of environmental risk factors (e.g. placement in solitary confinement, work status in prison) contributing to self-harm risk amongst people in prison. Qualitative studies suggest a role for a wider range of prison environment factors on mental health outcomes in prison (such as the prison regime, unstable environment and relationships with staff). However, the full range of environmental factors relevant to self-harm behaviour remains unclear.
We want to identify and estimate the effect size of a fuller range of environmental factors on self-harm behaviour through a longitudinal pilot study. A pilot study will allow us to assess the feasibility of carrying out a comprehensive prospective cohort study in future, and will collect data to inform a power calculation for such a study.
The study will take place in HMP Wandsworth, a large category B men’s prison in South London. New entrants to HMP Wandsworth aged over 18 years are eligible to participate. We will recruit a simple random sample of 300 men.
Participants will complete a set of baseline questionnaires (50-55 minutes) in a private interview room on the prison wing within one week of informed consent. The researchers will then follow up participants' via their healthcare and custodial records for 3 months. No direct contact with participants is planned after baseline assessment. The researchers will extract environmental exposure data from participants’ custodial records and from group-level data provided by the prison.
Understanding which prison environment factors may contribute to self-harm will help to inform prison environments and prison-wide strategies for reducing self-harm and will lay the groundwork for further research looking to robustly quantify the effects of environmental factors and predict those at highest risk of self-harm in prison through prediction modelling.
Summary of Results
: Introduction Self-harm is a major public health issue in the imprisoned population. Little is known about the impact of different aspects of the prison environment (prison environment factors) on self-harm. This exploratory pilot prospective cohort study in a large male remand prison in England examined a range of prison environ mental factors in relation to self-harm and estimated how much each contributed to the outcome.
Methods
A random sample of all prisoners starting a period of imprisonment at the study prison, totalling 149 people, took part in a clinical research interview, which assessed a range of known risk factors for self-harm in prison. Information concerning environmental factors, including staff numbers, cell placement and movements, and engagement in work and activities were collected from prison records. Incidents of self-harm in the 3 months after entering prison were measured using medical records and self-report at end of follow-up. We analysed the data using logistic regression to produce an odds ratio for each of the 14 prison environment factors (multivariable logistic regression) and adjusted for the effects of age, ethnicity and previous violent offending.
Results
55.7% of participants completed follow-up (83/149). Placement in a single-occupancy cell (OR 4.31, 95% CI 1.06-18.24, p = 0.041) and more frequent changes of cellmate (OR 1.52, CI 1.14-2.17, p = 0.009) and cell (OR 1.83, 95% CI 1.28-2.86, p = 0.003) were associated with an increased risk of self-harming behaviour. Participants who spent time in areas where there was a higher number of prisoners per prison staff member was significantly associated with reduced likelihood (odds) of self-harm in adjusted models (OR 0.89, CI 0.78-0.99, p = 0.039). Following sensitivity analyses, the associations between frequent cell changes and self-harm behaviour, and between single cell placement and self-harm ideation, remained statistically significant.
Discussion
This exploratory pilot study provides evidence from prospective longitudinal data regarding relationships between prison environmental factors and self-harm. The findings on single cell placement and frequent cell changes being related to increased self-harm are consistent with evidence in the existing literature, which is largely based on data from case-control studies. The finding regarding frequent cellmate changes predicting self-harm is new. The most plausible explanation for the association between more time in areas with more prisoners per staff member and lower chance of self-harm is reverse causality (i.e. those with self-harm directed to areas with higher staffing). The next step required is to replicate the findings in larger cohort studies that address the limitations of this pilot study.REC name
Wales REC 3
REC reference
22/WA/0007
Date of REC Opinion
1 Mar 2022
REC opinion
Further Information Favourable Opinion