Objectives

The aims of this study were to describe emergency department (ED) utilization by people in provincial prison and on release, and to compare with ED utilization for the general population.

Methods

We linked correctional and health administrative data for people released from provincial prison in Ontario in 2010. We matched each person by age and sex with four people in the general population. We compared ED utilization rates using generalized estimating equations, by sex and for high urgency and ambulatory care sensitive conditions.

Results

People who experienced imprisonment (N = 48,861) had higher ED utilization rates compared with the general population (N = 195,444), with rate ratios of 3.2 (95% CI 3.0–4.4) for men and 6.5 (95% CI 5.6–7.5) for women in prison and a range of rate ratios between 3.1 and 7.7 for men and 4.2 and 8.8 for women over the 2 years after release. Most ED visits were high urgency, and between 1.0% and 5.1% of visits were for ambulatory care sensitive conditions. ED utilization rates increased on release from prison.

Conclusions

People experiencing imprisonment in Ontario have higher ED utilization compared with matched people in the general population, primarily for urgent issues, and particularly in women and in the week after release. Providing high-quality ED care and implementing prison- and ED-based interventions could improve health for this population and prevent the need for ED use.