title: Impact of cigarette smoking on symptoms and quality of life  of adults with asthma managed in public primary care clinics  in Singapore: a questionnaire study.
abstract: BACKGROUND
  Cigarette smoking aggravates asthma exacerbations, yet some patients with asthma continue to smoke.
  
  
  OBJECTIVE
  To compare the quality of life of adult smokers and non-smokers with asthma.
  
  
  METHODS
  Asthma Quality of Life (AQLQ) questionnaires were administered to adult patients with asthma managed in primary care in  Singapore. The survey also included data of their asthma status including symptom profiles. Independent two-sample t-test, ANCOVA  model, χ2 test and ordinal logistic regression were used to compare the mean domain scores and the effect of smoking on nocturnal  symptoms and awakening, respectively.
  
  
  RESULTS
  357 adult asthma patients (183 non-smokers and 174 smokers) were recruited. Smokers were mainly male (p<0.001), single  (p=0.008), and younger (mean age 30 years) (p=0.007). They were more affected by nocturnal cough and wheezing (p=0.016). After  adjustment for age, gender, and asthma medications, the mean scores of the AQLQ 'symptoms' and 'emotional function' domains of  smokers were 0.41 (95% CI 0.10 to 0.72) and 0.50 (95% CI 0.16 to 0.84) points lower than for non-smokers, with no statistical  differences in the 'activity limitations' and 'exposure to environmental stimuli' domains.
  
  
  CONCLUSIONS
  Adult patients with asthma who smoke are more affected by nocturnal symptoms, with lower 'emotional function' scores  in the AQLQ.
authors.affiliation: SingHealth Polyclinics, Pasir Ris, Singapore. Tan.Ngiap.Chuan@singhealth.com.sg
authors.forename: Ngiap Chuan
authors.initials: NC
authors.lastname: Tan
authors.forename: Soh Heng Agnes
authors.initials: SH
authors.lastname: Ngoh
authors.forename: Stephanie Swee Hong
authors.initials: SS
authors.lastname: Teo
authors.forename: Teck Sin
authors.initials: TS
authors.lastname: Swah
authors.forename: Zhaojin
authors.initials: Z
authors.lastname: Chen
authors.forename: Bee Choo
authors.initials: BC
authors.lastname: Tai
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D003371:Cough / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data; D011788:Quality of Life; D012135:Respiratory Sounds / Q000503:physiopathology; D012846:Singapore; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires