How can we maximise the benefits of smoke-free prisons? Decision analytic model to predict potential impacts on public health

Introduction

Tobacco smoking prevalence remains high in disadvantaged populations such as people in prison. Smokefree prisons protect from smoking harms, however around 90% of people who smoke pre-prison, relapse to smoking shortly after release. If people released from smokefree prisons maintain abstinence this could benefit their health and finances. Knock-on effects of smoking relapse on families could also be avoided. Offering an intervention to reduce relapse to smoking on release has the potential to benefit the health and finances of the released person and their family.

This study assesses potential costs and outcomes for people previously imprisoned and their families, of smokefree prison policy and a hypothetical smoking cessation intervention.

Methods

A Markov model was developed for three populations: people previously in prison, partners, and children. Model states are based on smoking/vaping status. Four scenarios were modelled depending on whether vaping is permitted in prison and whether a hypothetical intervention was applied. The analysis was from healthcare payer and personal perspectives, over a lifetime. Costs include healthcare, personal (vaping and smoking) and the intervention. Outcomes include quality adjusted life-years. Several plausible scenarios were conducted due to uncertainty in parameters.

Results

Offering an intervention was beneficial for both vaping scenarios. For the person released from prison, results indicated that specific scenarios without vaping permitted in prison were more cost-effective (less costly and more beneficial) than with vaping permitted. However, sensitivity analyses highlighted the significant impact of vaping prevalence and relapse rates on outcomes, emphasising uncertainty in some parameters.

For both partner and child(ren), costs were higher and quality adjusted life-years lower for those living with a released prisoner who smokes compared to one who vapes or does not smoke/vape.