title: The Protective Effect of Hispanic Ethnicity on Chronic Obstructive Pulmonary Disease Mortality is Mitigated by Smoking Behavior.
abstract: BACKGROUND
  Studies in Hispanic/Latino populations have shown ethnicity to be either a predictive or protective factor for COPD mortality and it is unclear whether this disagreement is attributable to ethnic differences in smoking rates, smoking behavior or differences in genetic susceptibility.
  
  
  OBJECTIVE
  This study will examine the role of smoking behavior as a means of explaining differences in risk for COPD mortality between Hispanics and non-Hispanic whites.
  
  
  METHODS
  Participants were recruited into a cohort study from the San Luis Valley in Colorado beginning in the early 1980's and followed for mortality until 2012. COPD and cardiovascular disease are often comorbid conditions and account for the competing risk of CVD in the analysis of COPD mortality. Mortality searches were conducted regularly and all ICD codes were collected for mortality event. Primary and secondary causes of each event were assessed using appropriate codes.
  
  
  RESULTS
  Hispanic current smokers did not differ from NHW current smokers in years smoked (p=0.6) but Hispanic former smokers accumulated more years smoked compared to NHW former smokers (22 vs. 20, p=0.047). Hispanic ethnicity was significantly protective for COPD mortality adjusting for age, gender, pre-existing emphysema, hypertension and smoking status and accounting for the effect of CVD mortality (RR=0.58, 95% C.I. 0.34-0.99, p=0.035). Further adjustment for smoking behavior mitigated this effect.
  
  
  CONCLUSIONS
  The lower COPD mortality seen in Hispanic smokers may be due lower cumulative exposure to tobacco smoke. Thus, smoking behavior may play a key role in explaining differences in COPD mortality as they relate to Hispanic ethnicity.
authors: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora Colorado, USA.
authors: Gregory L
authors: GL
authors: Kinney
authors: Department of Geography and Environmental Sciences, University of Colorado Denver, Denver Colorado, USA.
authors: Deborah Sk
authors: DS
authors: Thomas
authors: National Jewish Hospital and University of Colorado Denver, Denver Colorado, USA.
authors: Lisa
authors: L
authors: Cicutto
authors: Department of Environmental Health, Colorado School of Public Health, University of Colorado Denver, Aurora Colorado, USA.
authors: Lee S
authors: LS
authors: Newman
authors: Department of Biostatistics, Colorado School of Public Health, University of Colorado Denver, Aurora Colorado, USA.
authors: Sharon
authors: S
authors: Lutz
authors: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora Colorado, USA.
authors: John E
authors: JE
authors: Hokanson
keywords: Cardiovascular Disease (CVD); Chronic obstructive pulmonary disease; International classification of disease; Smoking