Association between household type and false reporting of smoking among South Korean adults

Objective Self-reported smoking is prone to false reporting, potentially influenced by cultural norms and cohabiting family members. We examined the association between household type and false reporting among South Korean adults. Methods Using 2014–2021 Korean National Health and Nutrition Examination Survey data, we identified adults (≥19 years) with cotinine-verified smoking. Household types were classified as single-person, couple-only, parent-with-child or other. False reporting was defined as self-reporting as having never smoked or having previously smoked. Sex-stratified multivariable logistic regression was conducted after adjusting for relevant covariates. Results Among 8510 adults with cotinine-verified smoking (6754 males; 1756 females), false reporting prevalence (males/females) was 7.6%/24.2% in single-person households, 12.2%/37.4% in couple-only households, 12.1%/47.3% in parent-with-child and 11.9%/39.5% in other household types. Compared with single-person households, false reporting was more likely in parent-with-child (male, adjusted OR (aOR) 1.72, 95% CI 1.20 to 2.48; female, aOR 2.01, 95% CI 1.38 to 2.93) and other households (male, aOR 1.75, 95% CI 1.15 to 2.65; female, aOR 1.53, 95% CI 1.01 to 2.32). Moreover, among males, couple-only households showed increased odds (aOR 2.04, 95% CI 1.31 to 3.17). Individuals with false reporting were more likely to report having never smoked and, among males, were also more likely to report having previously smoked and current e-cigarette use. Conclusion These findings suggest that the presence and type of cohabiting family members increased the likelihood of false reporting of smoking, indicating identifiable high-risk groups and potential patterns in false reporting behaviour.