Secondhand smoke exposure and asthma outcomes among African-American and Latino children with asthma

Thorax. 2018 Nov;73(11):1041-1048. doi: 10.1136/thoraxjnl-2017-211383. Epub 2018 Jun 13.


Background: Secondhand smoke (SHS) exposures have been linked to asthma-related outcomes but quantitative dose-responses using biomarkers of exposure have not been widely reported.

Objectives: Assess dose-response relationships between plasma cotinine-determined SHS exposure and asthma outcomes in minority children, a vulnerable population exposed to higher levels of SHS and under-represented in the literature.

Methods: We performed analyses in 1172 Latino and African-American children with asthma from the mainland USA and Puerto Rico. We used logistic regression to assess relationships of cotinine levels ≥0.05 ng/mL with asthma exacerbations (defined as asthma-related hospitalisations, emergency room visits or oral steroid prescription) in the previous year and asthma control. The shape of dose-response relationships was assessed using a continuous exposure variable in generalised additive logistic models with penalised splines.

Results: The OR for experiencing asthma exacerbations in the previous year for cotinine levels ≥0.05 ng/mL, compared with <0.05 ng/mL, was 1.40 (95% CI 1.03 to 1.89), while the OR for poor asthma control was 1.53 (95% CI 1.12 to 2.13). Analyses for dose-response relationships indicated increasing odds of asthma outcomes related with increasing exposure, even at cotinine levels associated with light SHS exposures.

Conclusions: Exposure to SHS was associated with higher odds of asthma exacerbations and having poorly controlled asthma with an increasing dose-response even at low levels of exposure. Our results support the conclusion that there are no safe levels of SHS exposures.

Keywords: asthma epidemiology; tobacco and the lung.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Asthma / ethnology*
  • Asthma / etiology
  • Black or African American*
  • Child
  • Female
  • Hispanic or Latino*
  • Humans
  • Incidence
  • Male
  • Risk Assessment / methods*
  • Risk Factors
  • Tobacco Smoke Pollution / adverse effects*
  • United States / epidemiology
  • Young Adult


  • Tobacco Smoke Pollution