Objective: To determine the frequency of active smoking among patients with asthma and individuals without asthma by self-report and urinary cotinine measurement. Methods: This was a cross-sectional study conducted in the city of Salvador, Brazil, and involving 1,341 individuals: 498 patients with severe asthma, 417 patients with mild-to-moderate asthma, and 426 individuals without asthma. Smoking status was determined by self-report (with the use of standardized questionnaires) and urinary cotinine measurement. The study variables were compared with the chi-square test and the Kruskal-Wallis test. Results: Of the sample as a whole, 55 (4.1%) reported being current smokers. Of those, 5 had severe asthma, 17 had mild-to-moderate asthma, and 33 had no asthma diagnosis. Of the 55 smokers, 32 (58.2%) were daily smokers and 23 (41.8%) were occasional smokers. Urinary cotinine levels were found to be high in self-reported nonsmokers and former smokers, especially among severe asthma patients, a finding that suggests patient nondisclosure of smoking status. Among smokers, a longer smoking history was found in patients with severe asthma when compared with those with mild-to-moderate asthma. In addition, the proportion of former smokers was higher among patients with severe asthma than among those with mild-to-moderate asthma. Conclusions: Former smoking is associated with severe asthma. Current smoking is observed in patients with severe asthma, and patient nondisclosure of smoking status occurs in some cases. Patients with severe asthma should be thoroughly screened for smoking, and findings should be complemented by objective testing.

Objective: To estimate the frequency of secondhand smoke exposure among patients with asthma. Methods: A cross-sectional study of asthma patients and non-asthmatic controls using questionnaires to identify secondhand smoke exposure at home, school, work, and public places. Results: We studied 544 severe asthma patients, 452 mild/moderate asthma patients, and 454 non-asthmatic patients. Among severe patients, the mean age was 51.9 years, 444 (81.6%) were female, 74 (13.6%) were living with a smoker, 383 (71.9%) reported exposure in public spaces and, of the 242 (44.5%) who worked/ studied, 46 (19.1%) reported occupational exposure. Among those with mild/moderate asthma, the mean age was 36.8 years, 351 (77.7%) were female, 50 (11.1%) reported living with a smoker, 381 (84.9%) reported exposure in public settings and, of the 330 (73.0%) who worked/ studied, 58 (17.7%) reported occupational exposure. An association between secondhand smoke exposure and disease control was found among patients with mild/moderate asthma. Among those interviewed, 71% of severe asthma patients and 63% of mild/moderate asthma patients avoided certain places due to fear of secondhand smoke exposure. Conclusion: Secondhand smoke exposure is a situation frequently reported by a significant proportion of asthma patients. Individuals with asthma are exposed to this agent, which can hamper disease control, exacerbate symptoms and pose unacceptable limitations to their right to come and go in public settings.