Self-Reported Smoking Status and Exhaled Carbon Monoxide

Using a cutoff value of 6 ppm would potentially miss a large number of smokers, although this may vary with ethnicity. Epidemiologic studies should continue to use biochemical markers to validate responses to smoking surveys. However, the use of exhaled carbon monoxide measurements as a method of assessing the validity of self-reported smoking status may require additional analyses of whether the cutoff level should vary for different populations.