BACKGROUND@#In
firefighters,
smoking management is important because they are exposed to various harmful substances in their occupational
environment. Accurate surveys of
smoking status are essential to control
tobacco use. The main disadvantage of self-report
questionnaires, which are commonly used for investigating
smoking status, is the possibility that the subjects' response are invalid. If the validity of
firefighters' answers on
smoking questionnaires is not adequate, different
methods will be needed for investigating
smoking status in
firefighters.@*
METHODS@#This study was conducted on 445
male firefighters from 9
fire stations in Daegu (the city in
South Korea)
who visited a medical institution for medical checkup in 2016. The
urine cotinine test strip (DCT-102; CLIAwaived Inc., cut-off value = 200 ng/mL) was used to classify the actual
smoking status and to assess the validity of
self-reported
smoking status on
questionnaires. The
sensitivity,
specificity,
positive predictive value (PPV), and
negative predictive value (NPV) of the
smoking questionnaires were analyzed. Subjects testing positive in the
urine cotinine test (assumed the actual current
smokers) were selected. The frequency at which actual current
smokers were misclassified as current
non-smokers by the
questionnaire was calculated. Subjects' characteristics were analyzed for possible
association with any discrepancy between
self-reported
smoking status and
urine cotinine test results.@*RESULTS@#The
smoking rates among
firefighters surveyed using the
smoking questionnaire and the
urine cotinine test were 22.47% and 51.24%, respectively. Of the all subjects, 29.66% (n = 132) were misclassified. The
sensitivity of the
smoking questionnaire was 42.98%, the
specificity was 99.08%, the PPV was 98.00%, and the NPV was 62.32%. In the 228 subjects classified as current actual
smokers by the
urine cotinine test, 57.02% (n = 130) were misclassified on the
questionnaire. The misclassification rate increased with age. The degree of misclassification also increased when subjects had a
history of
disease.@*CONCLUSIONS@#In present study, the validity of the
smoking questionnaire for
firefighters was not suitable for investigating
smoking status due to low
sensitivity. To increase the validity of
smoking status
monitoring in
firefighters, consideration of the various factors like
survey environment, subjects' characteristics, and occupational factors is needed.