People in prison are among the most vulnerable groups in society. They are more likely to have been homeless and unemployed than people in the general community and often come from socioeconomically disadvantaged backgrounds (AIHW 2019).

People in contact with the criminal justice system have higher levels of mental health conditions, at-risk alcohol consumption, tobacco smoking, illicit drug use, chronic disease and communicable disease than the general population (AIHW 2019). This means that people in prison often have complex, long-term health needs. The health of people in prison is so much poorer than that of the general population, such that people in prison are often considered to be elderly at ages 45–55 (compared with at age 65 and over in the general community) (Baidawi 2011; Stojkovic 2007; Williams et al. 2014).