title: The impact of SHS exposure on health status and exacerbations among patients with COPD.
abstract: Secondhand smoke (SHS) is a major contributor to indoor air pollution. Because it contains respiratory irritants, it may adversely influence the clinical course of persons with chronic obstructive pulmonary disease (COPD). We used data from nonsmoking members of the FLOW cohort of COPD (n = 809) to elucidate the impact of SHS exposure on health status and exacerbations (requiring emergency department visits or hospitalization). SHS exposure was measured by a validated survey instrument (hours of exposure during the past week). Physical health status was measured by the SF-12 Physical Component Summary Score and disease-specific health-related quality of life (HRQL) by the Airways Questionnaire 20-R. Health care utilization for COPD was determined from Kaiser Permanente Northern California computerized databases. Compared to no SHS exposure, higher level SHS exposure was associated with poorer physical health status (mean score decrement -1.78 points; 95% confidence interval [CI] -3.48 to -0.074 points) after controlling for potential confounders. Higher level SHS exposure was also related to poorer disease-specific HRQL (mean score increment 0.63; 95% CI 0.016 to 1.25) and less distance walked during the Six-Minute Walk test (mean decrement -50 feet; 95% CI -102 to 1.9). Both lower level and higher level SHS exposure was related to increased risk of emergency department (ED) visits (hazard ratio [HR] 1.40; 95% CI 0.96 to 2.05 and HR 1.41; 95% CI 0.94 to 2.13). Lower level and higher level SHS exposure were associated with a greater risk of hospital-based care for COPD, which was a composite endpoint of either ED visits or hospitalizations for COPD (HR 1.52; 95% CI 1.06 to 2.18 and HR 1.40; 95% CI 0.94 to 2.10, respectively). In conclusion, SHS was associated with poorer health status and a greater risk of COPD exacerbation. COPD patients may comprise a vulnerable population for the health effects of SHS.
authors.affiliation: Division of Occupational and Environmental Medicine, University of California, San Francisco, CA 94143-0111, USA. mark.eisner@ucsf.edu
authors.forename: Mark D
authors.initials: MD
authors.lastname: Eisner
authors.forename: Carlos
authors.initials: C
authors.lastname: Iribarren
authors.forename: Edward H
authors.initials: EH
authors.lastname: Yelin
authors.forename: Stephen
authors.initials: S
authors.lastname: Sidney
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Katz
authors.forename: Gabriela
authors.initials: G
authors.lastname: Sanchez
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
mesh_terms: D000368:Aged; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006304:Health Status; D006760:Hospitalization; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D011788:Quality of Life; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D016138:Walking
chemical_list: D014028:Tobacco Smoke Pollution