Validation of the respiratory toxics exposure score (RTES) for chronic obstructive pulmonary disease screening

Int J Occup Med Environ Health. 2011 Dec;24(4):339-47. doi: 10.2478/s13382-011-0043-x. Epub 2011 Nov 16.


Objective: Our aim is to evaluate the validity of exhaled carbon monoxide (CO) and of a newly-created score as markers of Chronic Obstructive Pulmonary Disease (COPD).

Materials and methods: The CO level was measured in a derivation subsample of a cross-sectional study and linked to COPD diagnosis; its predictors were evaluated, and a scale was constructed. It was evaluated in a validation subsample and in a clinical setting.

Results: Individuals with COPD had higher CO levels than healthy individuals. CO level significant predictors were cigarettes per day, waterpipes per week, lower age, male gender, living close to diesel exhaust, heating home with the use of diesel, and having indoor family smokers. A score composed of CO predictors was able to significantly predict COPD (Ora = 4-7.5).

Conclusions: Coupled with the clinical judgment of physicians, this scale would be an excellent low-cost tool for screening COPD, in absence of spirometry.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Air Pollutants / adverse effects
  • Air Pollutants / analysis
  • Biomarkers
  • Breath Tests
  • Carbon Monoxide / analysis*
  • Cross-Sectional Studies
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Female
  • Hazardous Substances / adverse effects
  • Humans
  • Lebanon / epidemiology
  • Male
  • Population Surveillance / methods
  • Predictive Value of Tests*
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Pulmonary Disease, Chronic Obstructive / epidemiology


  • Air Pollutants
  • Biomarkers
  • Hazardous Substances
  • Carbon Monoxide