title: Asthma and risk of death from lung cancer: NHANES II Mortality Study.
abstract: OBJECTIVE
  Although smoking is the most important risk factor for lung cancer, nearly 10% of lung cancer is not attributable to smoking. Insights into risk factors for lung cancer other than smoking will become increasingly important, given decreasing trends in the prevalence of smoking. Prior research suggests asthma may increase the risk of lung cancer, particularly among nonsmokers.
  
  
  METHODS
  We used Cox regression analyses of data from a nationally representative sample of 9087 adults aged 30-75 years included in the NHANES II Mortality Study (1976-1992) to estimate the relative risk (RR) of death from lung cancer associated with self-reported asthma, independent of smoking.
  
  
  RESULTS
  Age-adjusted prevalence of smoking was 36.0%, and the age-adjusted prevalence of asthma was 6.1% (6.2% among nonsmokers) at baseline. During approximately 17 years of follow-up, 196 adults died of lung cancer (ICD-9 160-165). Among 6144 nonsmokers, the RR of lung cancer death comparing adults with asthma to those without was 1.69 (95% CI: 0.94-3.04) although the association was not statistically significant. For nonsmokers without a history of cancer, the RR was 2.53 (95% CI: 1.42-4.52). After exclusion of adults with emphysema and chronic bronchitis, the RR of lung cancer death associated with asthma was 3.54 (95% CI: 1.93-6.42).
  
  
  CONCLUSIONS
  Consistent with prior reports, we observed an increased risk of lung cancer mortality associated with asthma among nonsmokers without a history of cancer.
authors.affiliation: Emerging Investigations and Analytic Methods Branch, Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Brown
authors.forename: Karen E
authors.initials: KE
authors.lastname: Young
authors.forename: Robert F
authors.initials: RF
authors.lastname: Anda
authors.forename: Wayne H
authors.initials: WH
authors.lastname: Giles
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001249:Asthma / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D018570:Risk Assessment; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000401:mortality; D016019:Survival Analysis; D014481:United States