Prison smoking bans are associated with a substantial reduction in deaths from smoking related causes, such as heart disease and cancer, finds a US study published on thebmj.com today. Smoking related deaths were cut by up to 11% in state prisons with long-term bans in place.

In the United States at year end 2011, there were 1.4 million people in state prisons. Fifty to 83 percent of people in prison smoke - substantially higher than the general population outside prison.

US prisons have increasingly implemented smoking and tobacco bans, but the effects of smoking on mortality and the health benefit of these policies have not been evaluated. England and Wales are also implementing or considering complete bans on smoking in prison.

So a team of US researchers set out to determine the mortality attributable to smoking and years of potential life lost from smoking among people in prison - and whether bans on smoking in prison are associated with reductions in smoking related deaths.

Their results are based on surveys of inmates in state correctional facilities and data on state prison tobacco policies and deaths in prisons across the United States.

The most common causes of deaths related to smoking among people in prison were lung cancer, heart disease, stroke, and chronic lung disease.

Smoking attributable mortality and years of potential life lost rates were 360 and 5,149 per 100,000, respectively. These figures are higher than rates in the general US population (248 and 3,501 per 100,000, respectively).

The number of states with any smoking ban increased from 25 in 2001 to 48 by 2011. In prisons, the mortality rate from smoking related causes was lower (110 per 100,000) during years with a ban than during years without a ban (129 per 100,000).

Prisons that implemented smoking bans had a 9% reduction in smoking related deaths. Bans in place for longer than nine years were associated with 11% reductions in all smoking related deaths, a 19% reduction in cancer deaths, and a 34% reduction in pulmonary deaths compared with places with no ban.

Smoking contributes to substantial excess mortality in prisons, and prison tobacco control policies are associated with reduced mortality, through reductions in smoking and exposure to second-hand smoke, say the authors.

"These findings suggest that smoking bans have health benefits for people in prison, although bans impose limits on individual autonomy and many people resume smoking after release," they add.

And they call for ongoing research and implementation efforts "to promote effective long term cessation in prisons and after release as part of a comprehensive tobacco strategy for this high risk group."