The Impact of Smoking and Multiple Health Behaviors on All-Cause Mortality

Four common health risk behaviors have the greatest impact on all-cause mortality risk, but studies are needed with larger samples and the appropriate age range for cigarette smokers. We examined the impact of smoking in the context of multiple health behaviors on all-cause mortality using a nationally representative sample of adults aged 30 and older in the United States. National Health Interview Survey data from 1997 to 2005 were linked to the National Death Index with a follow-up to December 2015. The primary dependent variable was all-cause mortality, and the primary predictors were smoking, heavy drinking, physical inactivity, and unhealthy weight (underweight or obesity). The sample contained 189,087 individuals (≥ age 30; population estimate = 140.7 million). Our primary statistical analysis tool involved fitting Cox proportional hazards models. Our findings demonstrated that smoking led to the highest mortality risk among the four risk behaviors examined, but more than half of smokers engaged in at least one additional health risk behavior. Smokers who engaged in multiple health behaviors experienced higher increased mortality risks: smoking combined with one other health risk behavior increased mortality risk by 32% and by 82% when combined with two behaviors. Engaging in all four risk behaviors more than doubled the mortality risk of smokers. Smoking cessation interventions that address multiple risk behaviors-physical inactivity, heavy drinking, and unhealthy weight-will likely prevent premature death better than interventions that address only smoking.