When surveyed in a recent study, Danish people living with HIV underestimated the extent to which smoking would likely cut into their life expectancy, aidsmap reports.

Publishing their findings in the Journal of Acquired Immune Deficiency Syndromes, researchers in Denmark polled two groups of people about their perceived life expectancy, including 937 HIV-positive people and 6,147 age-matched controls from the general population.

The participants with HIV had a median age of 51 while the controls had a median age of 53. Eighty-eight percent of the overall group was male. Among those with HIV,30 percent werecurrentsmokers and 35 percent were former smokers. Among those without the virus, 14 percentwere currentsmokersand 38 percentwere former smokers.

On average, the people with HIV believed they would live to 80.5 years old, while the control group anticipated living to 85.2 years old.

People with HIV said they believed smoking would cut into their life expectancy by 3.65 years while the control group believedsmoking would shave 4.36 years off their own lives.

Aside from taking antiretrovirals (ARVs), quitting smoking is the most effective move smokers living with well-treated HIV can make to lower their risk of illness and death, sincesmoking perhaps doubles their overall risk of death. Research has suggested that people with HIV who smoke—about 40 percent of those with the virus in the United States do so—losemore years of life to smoking than to the virus provided they are taking ARVs. One study estimated that the average 35-year-old man living with fully suppressed HIV has a life expectancy of 78 if he doesn’t smoke and just 70 if he does.

For a POZ feature article on smoking’s particular harms among people with HIV as well as tips on how to quick, click here.

To read the aidsmap article, click here.

To link to the letter to the editor, click here.