Mortality after release from incarceration in New Zealand by gender: A national record linkage study

Ruth Cunningham; Paula Toko King; Kendra Telfer; Sue Crengle; Julia Carr; James Stanley; Sheree Gibb; Bridget Robson

doi:10.1016/j.ssmph.2022.101274

Mortality after release from incarceration in New Zealand by gender: A national record linkage study

SSM Popul Health. 2022 Nov 1:20:101274. doi: 10.1016/j.ssmph.2022.101274. eCollection 2022 Dec.

Authors

Ruth Cunningham¹, Paula Toko King², Kendra Telfer¹, Sue Crengle³, Julia Carr⁴, James Stanley¹, Sheree Gibb¹, Bridget Robson²

Affiliations

¹ Department of Public Health, University of Otago, Wellington, New Zealand.
² Te Rōpū Rangahau Hauora a Eru Pōmare, University of Otago, Wellington, New Zealand.
³ Department of Preventive and Social Medicine, University of Otago, New Zealand.
⁴ School of Medicine, Griffith University, Australia.

Abstract

Background: People who enter and leave places of incarceration experience considerable health inequities and are at increased risk of premature death compared to the general population. Causes of premature death in this population vary markedly between countries and so country-specific information is needed. Additionally, there is a lack of large population-based studies which can disaggregate mortality risk based on person and incarceration factors. This study is the first examination of mortality in the period following release from incarceration in New Zealand.

Methods: We linked deidentified administrative data on incarceration and release between 1 January 1998 and 31 December 2016 with national mortality data for the same period to examine mortality after release in those who had been incarcerated for at least 1 day. Age standardised mortality rates and mortality ratios compared to the general New Zealand population were calculated separately for men and women, for releases from remand compared with prison, and by cause of death and time since release.

Results: 90,195 individuals (13% women, 49% Māori) were followed up for 9.4 years after release from incarceration, with 4,764 deaths over the follow-up period. The overall standardised mortality ratio was 3.3 (95% CI 3.2, 3.4) compared to the general population, and higher for women (3.8) than men (2.7). The most common causes of death were cardiovascular disease, cancer and suicide. Rates of death were similar following release from remand versus prison, however suicide rates were highest following release from remand. Regardless of the type of incarceration, mortality was highest in the first month after release.

Conclusion: Experience of incarceration in New Zealand is associated with high rates of mortality from both chronic conditions and external causes. There are urgent policy imperatives to recognise and actively address the increased health and mortality risks faced by people released from New Zealand prisons.

Keywords: Health equity; Incarceration; Mortality; Prison; Women; ‘Integrated data infrastructure’.