Importance An increasing proportion of US smokers smoke at low intensity and not every
day. Some nondaily smokers have always had this pattern, whereas others previously
smoked daily. The effect of reducing the level of smoking from daily to nondaily smoking and
the dose response at low smoking levels are poorly understood. Objective To evaluate risk
of all-cause and cause-specific mortality among nondaily and daily cigarette smokers, by
cigarettes per month, years after reducing from daily to nondaily smoking, and years since …