Background: Men and women who smoke tend to show less compliance to screening guidelines than nonsmokers.However, a recent study in Korea showed that self-reported female smokers constituted less than halfof cotinine-verified smokers. Therefore, the aim of this study was to identify hidden smokers using cotinineverifiedmethod and examine cancer screening behavior according to biochemically verified smoking status.Materials and
Methods: Among 5,584 women aged 30 years and older who participated in the Fourth and FifthKorea National Health and Nutrition Examination Survey (KNHANES), 372 (6.66%) hidden smokers wereidentified based on interview responses and verified by urinary cotinine levels. We compared cancer-screeningbehavior (cervical, breast, stomach, and colon cancer) of female hidden smokers to that of non-smokers and selfreportedsmokers by cross-sectional analysis.
Results: Hidden female smokers had significantly lower adherenceto breast cancer screening compared to non-smokers (aOR (adjusted odds ratio) [95% CI] = 0.71 [0.51–0.98]).Adherence to stomach cancer (aOR [95% CI] = 0.75 [0.54–1.03]) and cervical cancer (aOR [95% CI] = 0.85[0.66–1.10]) screening was also lower among hidden female smokers compared to non-smokers. Self-reported(current) smokers showed lowest adherence to cervical cancer (aOR: 0.64, 95% CI0.47-0.87), breast cancer(0.47 [0.32-0.68]), stomach cancer (0.66[0.46-0.95]), and colon cancer (0.62 [0.38-1.01]) screening compared tonon-smokers, followed by female hidden smokers, then non-smokers. These lower adherence rates of currentsmokers were attenuated after we incorporated hidden smokers into the current smoker group.
Conclusions:Cancer screening adherence of female hidden smokers was lower than cotinine-verified non-smokers but higherthan current smokers. Considering the risk of smoking-related cancer among women, identifying hidden smokersis important to encourage appropriate cancer screening.