title: The effectiveness of breath carbon monoxide analyzer in screening for environmental tobacco smoke exposure in Saudi pregnant women.
abstract: BACKGROUND
  Exposure to environmental tobacco smoke (ETS) has harmful effects on the pregnancy outcomes similar to those observed in actively smoking pregnant women. The aim of this study was to estimate the sensitivity and specificity of the breath carbon monoxide (BCO) analysis in the assessment of smoking status among Saudi pregnant women, including ETS exposure compared to self-reported tobacco smoke exposure.
  
  
  METHODS
  A cross-sectional design was used during January 2012, 560 pregnant women, irrespective of their gestational age, agreed to undergo BCO testing and completed the data collection sheet for the study. Sensitivity, specificity, positive and negative predictive values were calculated to compare the BCO test with self-reported exposure to ETS.
  
  
  RESULTS
  Of the study population 151 (27%) women self-reported ETS exposure during the index pregnancy, 409 (73%) self-reported non-exposure. Sensitivity of the test was 32.5% (95% CI; 25.2-40.3%), the Specificity was much higher at 69.2% (95% CI; 64.4-73.5%), the positive predictive value was 28% (95% CI, 21.9-35.1%), and the negative predictive value was 73.5% (95% CI; 68.9-77.7%).
  
  
  CONCLUSIONS
  The BCO test is an ineffective tool to detect the level of ETS exposure among Saudi pregnant women.
authors.affiliation: Sheikh Bahamdan Research Chair of Evidence-based Healthcare and Knowledge Translation, Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Rasmieh Ayed
authors.initials: RA
authors.lastname: Alzeidan
authors.forename: Ahmed Amin
authors.initials: AA
authors.lastname: Mandil
authors.forename: Amel Ahmed
authors.initials: AA
authors.lastname: Fayed
authors.forename: Hayfaa Abdulmajeed
authors.initials: HA
authors.lastname: Wahabi
keywords: Breath carbon monoxide analyzer; Saudi Arabia; environmental tobacco smoke; pregnancy