This study validated a self-reported smoking prevalence questionnaire again
st urinary cotinine levels among women referred to a Sydney based public ho
spital colposcopy clinic over the period November 1997 to June 1998. Of 213
eligible women, 160 (75%) agreed to participate. Of these, 151 (94%) compl
eted the smoking prevalence item and 130 (86%) also provided a urine specim
en. 40% (95% CI: 33%-49%) of respondents self-reported as current smokers.
Observed agreement between self-reported and biochemically validated smokin
g status was 94% compared with 52% chance agreement (kappa = 0.87, p < 0.00
1). This high level of agreement was also robust to sensitivity analyses us
ing a more conservative cutoff for the urinary cotinine levels. We conclude
that self-reported smoking status provides valid estimates of actual rates
of smoking among women referred with abnormal cervical smears.