Melbourne, May 29 (IANS): Former prisoners with a history of risky drug use, mental illness or poverty are more likely to end up behind the bars again, says a study that looked into the health factors that influence repeat offence.

The researchers also found that ex-prisoners who are obese, suffer from various chronic diseases or have had a history of self-harm or suicidal behaviour are less likely to return to custody.

The results could be used to predict whether a person released from prison will end up in custody again or not.

"Most of these predictors are modifiable and could potentially serve as targets for re-entry interventions," said researcher Emma Thomas from the University of Melbourne in Australia.

The study involved interviews with 1,322 adult prisoners from seven prisons in Queensland in Australia before and after their release.

Participants who reported risky use of cannabis, amphetamines or opioids prior to being incarcerated or who had committed a drug-related crime were at higher risk of returning to prison.

These drug-related issues often go hand in hand with other health factors to compound the likelihood of further jail time.

Such factors include whether someone has evidence of an intellectual disability, has a history of mental illness or has been diagnosed with a sexually transmitted disease.

People who lived below the poverty level before being incarcerated and those who did not rate the importance of their physical health highly were also more likely to end up back in prison.

On the flip-side, obese and chronically ill ex-prisoners were less likely to return to custody. This was also true for those who lead a sedentary lifestyle.

According to Thomas, this might be partly because those with chronic ill health are less capable of engaging in some sort of criminal activity.

The study was published in Springer's journal Health & Justice.