Does South Korea have hidden female smokers: discrepancies in smoking rates between self-reports and urinary cotinine level

Abstract

BackgroundFemale smoking is perceived very negatively in East Asian countries such as South Korea, Japan, and China, as well as in Islamic countries. These countries’ self-reported surveys (SRs) tend to produce results that underestimate the number of smokers, owing to the social desirability response bias. The present study seeks to assess South Korea, Europe, and the Americas, by comparing data from SRs with those from urinary cotinine samples.MethodsCurrent smoking rates were calculated using the SRs and the urinary cotinine concentration (UCC) methods according to socioeconomic factors. In order to examine response accuracy regarding current smoking status in the SRs, participants who both completed the SRs and acquired UCC results were subject to analyses of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and difference ratio (DR) with respect to gender, age, region, economic level, household status, and the presence of chronic disease.ResultsBased on self-reports, the current smoking rate among women was 7.1% (official smoking rates), while that according to the UCC was 18.2%; the rates for men were 47.8% and 55.1%, respectively. The sensitivity of males was 0.8553, the specificity 0.9768, PPV 0.9783, NPV 0.8465, and the difference ratio (DR) was 1.143. The sensitivity for females was 0.3670, the specificity 0.9956, PPV 0.9486, NPV 0.8761, and the DR was 2.6. These results exhibit a very low response alignment rate compared to males.ConclusionThis study shows that the actual female smoking rate is significantly higher than that reported officially, but also that the gap is decreasing steadily. Females exhibited a higher rate of false responses, which resulted in an underestimation of the female smoking rate.

The association between periodontitis and sleep duration

“…The association has shown to be prevalently non-linear for CPI ≥ 3 case definition models, and conversely prevalently linear for CPI = 4 models. Since the association became linear after restricting to females also in CPI ≥ 3 model, a possible explanation could be that the non-linear association observed in the total population was also in this case due to residual confounding by smoking (Korean women have low cigarette smoking rate, contrary to Korean men - Park et al 2014). However, it is not possible to exclude that the non-linear association was due to other factors, such as a direct biological effect of sleep duration on periodontitis or viceversa.…”

“…The reasons of these effect modifications need to be further investigated, but the reduction of the estimate for some subgroups could be at least in part related to residual confounding of smoking (e.g. in current smokers, males and higher lead blood levels) (Mannino et al 2005, Park et al 2014. The association has shown to be prevalently non-linear for CPI ≥ 3 case definition models, and conversely prevalently linear for CPI = 4 models.…”

Relationship between women's smoking and laryngeal disorders based on the urine cotinine test: results of a national population-based survey

“…4 Park et al measured the female smoking rate with urine cotinine concentrations and found that the female smoking rate in Korea was 18.2%, triple the self-reported smoking rate. In particular, women in their 30s had a biochemical test smoking rate that was three times higher than their self-reported smoking rate 3. The female smoking rate in Korea, as determined by urine cotinine concentration, is higher than the average female smoking rate of OECD countries.…”

“…Since East Asian countries have especially strong negative perceptions of women smokers, they tend not to let other people around them know about their smoking 24 18 19 According to Park et al ,3 a higher proportion of females hid their smoking than males, and one out of every two female smokers hid their smoking behaviour in self-reported questionnaire surveys. Since the self-reported smoking rate is likely to be underestimated, biochemical tests are required in addition to self-reported questionnaires in order to determine the exact relationship between smoking and laryngeal disorders.…”

Socio-demographic and clinical factors contributing to smoking cessation among men: a four-year follow up study of the Korean Health Panel Survey

“…This study used current smokers in Korean men, who account for most smokers in Korea. Females may not accurately report smoking status because of cultural reason [14]. Therefore we used 2,972 subjects who were current smokers among men aged 18 and older in 2009 as a baseline.…”