Abstract

Author(s)

Grant Sara, Patrick Gould

Introduction

Mental health service users experience significant health inequalities, including less access to preventative care and higher rates of physical health conditions. This study investigates the risks of hospitalisation for vaccine-preventable conditions among mental health service users in New South Wales, Australia.

Method

Using linked population data, we identified all hospitalisations for 19 vaccine-preventable conditions between 2015 and 2020 for adult mental health service users and other NSW residents. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were calculated to determine the relative risks of VPH, after standardising for age and sex. A secondary analysis examined admissions including the NSW COVID-19 delta wave up to September 2021.

Results & Findings

We identified 94,180 vaccine preventable hospitalisations. Mental health service users had more than three times the rate of vaccine-preventable hospitalisations compared to other NSW residents (aIRR 3.2, 95% CI 3.1 – 3.3). Risks were highest for hepatitis B (aIRR 4.4, 95% CI 4.3 – 4.6) but elevated for all conditions, including influenza, herpes zoster and COVID-19 (aIRR 2.0, 95% CI 1.9 – 2.2). Mental health service users were younger at the time of their first VPH admission, with the largest age gap observed for vaccine-preventable pneumonias (11-13 years younger).

Discussion

High VPH rates may reflect lower vaccination rates, greater risk of severe illness, or barriers in accessing community care. The findings highlight the importance of vaccine-preventable illness as a contributor to health inequalities. MH service users need equal access and prioritisation in vaccination policies and strategies. Collaborative approaches, with mental health services, physical health services and lived experience experts working together, are crucial if we are to succeed in “Becoming an Equally Well Country”.