Impact of smoking on asthma symptoms, healthcare resource use, and quality of life outcomes in adults with persistent asthma.

Background: Smoking habits of asthmatics are similar to those of the general population. However, little attention has been paid to the associations between smoking and asthma-related outcomes.

Objective: To evaluate relationships between cigarette smoking, asthma symptoms, and asthma-related resource utilization in subjects with persistent asthma.

Method: A stratified, random sample of adults from France, Germany, and the UK with persistent asthma were surveyed in 2001 through 2004. Statistical analyses compared asthma symptoms and healthcare resource utilization for cigarette smokers compared with those for non-smokers.

Results: Analyses included 1109 subjects with persistent asthma symptoms in 2001-2003 and 852 subjects with persistent asthma symptoms in 2004. Using multivariate analysis of data from eligible subjects in 2004 that did not have concomitant chronic obstructive pulmonary disease and adjusting for subjects' baseline and demographic characteristics, cigarette smokers were more likely to experience nighttime symptoms (OR 1.46, 95% CI 1.07, 1.97 P = 0.015) and were more likely to use healthcare resources than were non-smokers (P < or = 0.004). Findings were similar in a secondary analysis of subjects < or =55 years of age.

Conclusions: Cigarette smoking appears to be associated with more asthma symptoms and more ED visits and hospitalizations in adults with persistent asthma.