Assessment of the relationship between self-reported smoking rate and Ecolyzer measurement.

The relationship between self-reported smoking rates and Ecolyzer measurements of carbon monoxide was assessed in a series of 4 studies. Factors such as the reactive effects of prior measurement and the time period of administration were examined. In general, a close relationship between Ecolyzer readings and self-reported smoking rates was found. Prior Ecolyzer testing did not appear to reduce the strength of the relationship of Ecolyzer measurement to self-report at subsequent administrations. Thus, support was found for the use of carbon monoxide measurement as a valid means of corroborating self-report data. Implications for future research in this area were discussed.