# Clinical features and mortality outcomes of people transferred from prison to forensic mental health units: a nationwide 14-year retrospective cohort study

## TL;DR

This study examines the clinical features and high mortality rates of individuals transferred from prison to psychiatric hospitals in New Zealand over 14 years.

## Contribution

The study provides a nationwide analysis of mortality outcomes in a forensic mental health cohort with detailed demographic and clinical data.

## Key findings

- The cohort had a mortality ratio 4.7 times higher than the general New Zealand population.
- 60% of deaths were from natural causes, and 40% were from injuries, including suicide.
- Most individuals had psychotic or bipolar disorders and high rates of substance use.

## Abstract

To describe a cohort of people transferred from prison to psychiatric hospital care and their mortality outcomes.

Retrospective nationwide cohort of people (n = 1320) transferred from prison to a psychiatric hospital in New Zealand from 2009 to 2022. Follow up commenced at the first transfer and ended on 30 June 2023 or death if earlier. Ministry of Health records were used to describe the cohort and their service utilization profile. Records were linked to official mortality data, and mortality ratios were calculated using publicly available life tables.

The cohort was 85% male and 55% Māori, with a median age of 31.2 years. Most had a psychotic disorder (74%) or bipolar disorder (11%) and there were high levels of coexisting substance use disorder. Follow-up duration ranged from 2 months to 14.5 years (median 7.5 years) after the first transfer, of which 17% was in a psychiatric hospital. The age and sex-standardised mortality ratio for the cohort compared to the New Zealand population was 4.7 (95% CI 3.6–5.9). Among deaths with a known cause, 60% were from natural causes and 40% were from injuries including suicide.

Despite extended periods of psychiatric hospitalization there was high mortality among people in the cohort. Investment in targeted prevention and coordinated, continuous healthcare is needed for people with a serious mental illness who experience incarceration.