title: Evaluation of objective measures of smoking status--a prospective clinical study in a group of head and neck cancer patients treated with radiotherapy.
abstract: The present study was undertaken to evaluate objective measures of the smoking status of head and neck cancer patients during the course of radiotherapy. This was done by conducting a weekly structured interview, and measurement of carbon monoxide in expired air and of serum concentration of cotinine, the major metabolite of nicotine. These methods were tested prospectively in a series of 20 patients with head and neck cancer treated with radiotherapy. The results showed significant differences in the levels of end-expired carbon monoxide as well as serum cotinine among the different self-reported smoking groups. Combining the two objective measures and the interview data, the study revealed that up to 50% of self-reported non-smokers were in fact smoking actively. Measurement of end-expired carbon monoxide levels was found to be a precise indicator of smoking in the hours preceding measurement. Serum cotinine was a valuable measure of true smoking status. Assuming that this assay reflects the true smoking status, sensitivity, specificity and positive predictive value of self-reporting in this patient population was 79%, 80%, and 92%, respectively. In research aiming to investigate possible relations between smoking and radiotherapy, it is recommended that patients' smoking status be evaluated objectively as a supplement to self-reporting, at least in the head and neck cancer patients.
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jonas
authors.initials: J
authors.lastname: Hald
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
authors.forename: Cai
authors.initials: C
authors.lastname: Grau
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001944:Breath Tests; D002248:Carbon Monoxide / Q000378:metabolism*; D003367:Cotinine / Q000097:blood*; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012650:Self Disclosure; D012680:Sensitivity and Specificity; D012907:Smoking; D016540:Smoking Cessation / Q000379:methods*
chemical_list: D015415:Biomarkers; D002248:Carbon Monoxide; D003367:Cotinine