The longitudinal analysis for the association between smoking and the risk of depressive symptoms.

BACKGROUND: Despite high smoking rate in people with depressive symptoms, there is ongoing debate about relationship between smoking and depressive symptoms. METHODS: Study participants were 57,441 Korean men. We collected their baseline data between 2011 and 2012, and conducted follow-up from 2013 to 2019. They were categorized by smoking status (never: < 100 cigarettes smoking in life time, former: currently quitting smoking, and current smoker: currently smoking), smoking amount (pack/day and pack-year) and urine cotinine excretion. The development of depressive symptoms was determined in CES-D score ≥ 16. Cox proportional hazards model was used to analyze the multivariable-adjusted hazard ratio (HR) and 95% confidence intervals (CI) for depressive symptoms in relation to smoking status, smoking amount, and urine cotinine excretion. RESULTS: During 6.7 years of median follow-up, the risk of depressive symptoms increased in order of never (reference), former (HR = 1.08, 95% CI: 1.01-1.15) and current smoker (HR = 1.24, 95% CI: 1.16-1.32). Among current smoker, the risk of depressive symptoms increased proportionally to daily smoking amount (< 1 pack; HR = 1.21, 95% CI: 1.13-1.29, and ≥ 1 pack; HR = 1.34, 95% CI: 1.23 - 1.45). This pattern of relationship was consistently observed for pack-year in former smoker and current smoker. Additionally, urine cotinine excretion was proportionally associated with the risk of depressive symptoms. CONCLUSION: Exposure to smoking was associated with the increased risk of depressive symptoms. Dose dependent relationship was observed between smoking amount and the risk of depressive symptoms.

Comparison of secondhand smoking exposure between self-report and creatinine-corrected urine cotinine: Result from Korean NHANES 2009-2018.

BACKGROUND/PURPOSE: Second-hand smoking (SHS) is usually examined by self-report (SR). However, there is a possibility that SR may not accurately measure SHS exposure. This study aimed to identify yearly trends and gender differences in SHS by SR and cotinine. METHODS: We used data from the 2009-2018 Korea National Health and Nutrition Examination Survey (KNHANES) and included adults aged 19 years and older. We analyzed data of 47,907 respondents on SHS exposures in the past week and of 23,572 respondents who had both urine cotinine and creatinine measurements. SHS exposure was defined as those who answered 'yes' to whether or not they were exposed to smoking by SR. We performed descriptive analysis, Average annual percentage change (AAPC), and multiple regression analysis. All analyses were weighted reflecting the multi-stratified cluster sampling. RESULTS: Exposure to SHS indoors at the work place (WSHS) (2009: 44.8%, 2018: 12.3%), indoors at home (HSHS) (2009: 14.1%, 2018: 3.9%), and indoors at public places (PSHS) (2013: 55.6%, 2018: 15.4%) decreased steadily over the years. WSHS and PSHS exposure was higher for males but HSHS was higher for females. However, the concentration of cotinine-to-creatinine ratio (Co/Cr) was higher among females regardless of SHS exposure status and environment. Multiple regression analysis showed that among males, the association between Co/Cr education level and WSHS was the strongest, and among females, the association was the strongest with HSHS. In addition, home exposure to SHS intensified the differences in Co/Cr levels between males and females. CONCLUSION: Our study confirmed that cotinine-induced SHS showed different results by year and gender compared to SR. In particular, Co/Cr level in females was higher than in males regardless of exposure by SR, suggesting that SR did not correctly evaluate SHS. To reflect reality more accurately, biomarkers should be monitored along with SR.

Variability in the association of smoking status with the prevalence of diabetes mellitus in the Korean population according to different definitions of smoking status: analysis based on the Korea National Health and Nutrition Examination Survey (2014-2020).

We evaluated the association between smoking and diabetes, as well as the effects of gender differences and hidden smoking among females on this association using nationally representative data. Analyzing data from 44,049 individuals aged 19 and older, we utilized multivariable logistic regression to investigate associations, controlling for sociodemographic factors. Subgroup analysis based on smoking status determined factors associated with diabetes. To better our understanding of the smoking-diabetes relationship, we introduced a new variable, survey-cotinine verified smoking status (SCS). This study provides valuable insight by exploring the correlation between smoking and diabetes using different definitions of smoking status. Both male and female smokers showed correlations with diabetes according to cotinine-verified smoking status (OR: 1.22 and 1.48, respectively). According to smoking amount, cotinine-verified heavy smokers correlated with diabetes in males (OR: 1.37), while light smokers exhibited a negative correlation with diabetes in females for both cotinine-verified smoking status (OR: 0.60) and survey-cotinine verified status (OR: 0.58) Smoking was associated with diabetes in the overall population, with gender differences observed. When evaluating this association, we should consider variables of smoking amount, passive and intermittent smoking, and specifically, account for the influence of hidden smoking among females, particularly when utilizing self-reported questionnaires in Korea.

This study examines the association between smoking status and diabetes, focusing on gender-specific patterns, using a nationally representative sample. To increase the accuracy of smoking assessments, a new variable based on cotinine-determined smoking status is used. The study sheds light on the prevalence of under-reporting among female smokers in the Korean population, revealing important insights for future research and public health interventions. These findings underscore the importance of considering hidden smoking among women when investigating the relationship between smoking and diabetes, particularly when using self-reported questionnaires.

Concentrations of urine cotinine and hydroxycotinine among US children, adolescents, and adults: data from NHANES 2013-2014.

Purpose: The objective of this study was to evaluate variabilities in the levels of urine cotinine and hydroxycotinine by age, gender, race/ethnicity and smoking status among US residents.Materials and methods: Data from NHANES (N = 3135) were analysed by fitting regression models with log10-transformed values of urine cotinine and hydroxycotinine as dependent variables. Separate models were fitted for children aged 6-11 years, adolescents aged 12-19 years, and adults aged ≥20 years. Models were stratified by smoking status. Those self-reporting using combustible and/or smokeless tobacco products during the last 5 days were classified as being smokers.Results: No gender differences were observed. Among non-smokers, non-Hispanic blacks had the highest levels of cotinine and hydroxycotinine and Hispanics had the lowest levels of cotinine and hydroxycotinine. Among smokers, non-Hispanic whites had the highest levels of cotinine and hydroxycotinine. Exposure to environmental tobacco smoke at home and other indoor environments was associated with as much as 500% higher levels of cotinine and hydroxycotinine.Conclusions: In addition to currently available data on cotinine in serum and NNAL in urine, availability of data on cotinine and hydroxycotinine in urine provides another tool to monitor the smoking health of the US population.

Exposure to prenatal secondhand smoke and early neurodevelopment: Mothers and Children's Environmental Health (MOCEH) study.

BACKGROUND: The association between exposure to secondhand smoke (SHS) during pregnancy and a child's neurodevelopment has not been established yet. We explored the association between prenatal exposure to SHS and neurodevelopment at 24 months of age considering genetic polymorphism and breastfeeding in 720 mothers and their offspring enrolled in the Korean multicenter birth cohort study (Mothers and Children Environmental Health, MOCEH). METHODS: We quantified urine cotinine concentrations in mothers once from 12th to 20th gestational weeks and excluded those whose urine cotinine levels exceeded 42.7 ng/ml to represent SHS exposure in early pregnancy. Mental developmental index (MDI) and psychomotor developmental index (PDI) values were measured using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II) at 24 months of age. A general linear model was used to assess the relationship between maternal urinary cotinine level and neurodevelopment. RESULTS: MDI scores were inversely associated with cotinine [ß = - 2.73; 95% confidence interval (CI): - 5.32 to - 0.15] in children whose mothers had early pregnancy urinary cotinine levels >1.90 ng/ml. No association was evident in children whose mothers had cotinine levels ≤1.90 ng/ml. This negative association was more pronounced in children whose mothers had both Glutathione S-transferases mu 1 (GSTM1) and theta 1 (GSTT1) null type [ß = - 5.78; 95% CI: -10.69 to - 0.87], but not in children whose mothers had any present type of GSTM1/GSTT1 [ß = - 1.64; 95% CI: -4.79 to 1.52]. The association was no longer significant when children received breast milk exclusively for up to 6 months [ß = - 0.24; 95% CI: -4.69 to 4.20] compared to others [ß = - 3.75; 95% CI: -7.51 to 0.00]. No significant association was found for PDI. CONCLUSIONS: Maternal exposure to SHS during pregnancy may result in delayed MDI in early childhood. This effect might be modified by genetic polymorphism and breastfeeding behavior.

Trends in children's exposure to second-hand smoke in the INMA-Granada cohort: an evaluation of the Spanish anti-smoking law.

The smoke-free legislation implemented in Spain in 2006 imposed a partial ban on smoking in public and work places, but the result did not meet expectations. Therefore, a more restrictive anti-smoking law was passed five years later in 2011 prohibiting smoking in all public places, on public transport, and the workplace. With the objective of assessing the impact of the latter anti-smoking legislation on children's exposure to second-hand smoke (SHS), we assessed parent's smoking habits and children's urine cotinine (UC) concentrations in 118 boys before (2005-2006) and after (2011-2012) the introduction of this law. Repeated cross-sectional follow-ups of the "Environment and Childhood Research Network" (INMA-Granada), a Spanish population-based birth cohort study, at 4-5 years old (2005-2006) and 10-11 years old (2011-2012), were designed. Data were gathered by ad-hoc questionnaire, and median UC levels recorded as an objective indicator of overall SHS exposure. Multivariable logistic regression was used to examine the association between parent's smoking habits at home and SHS exposure, among other potential predictors. An increase was observed in the prevalence of families with at least one smoker (39.0% vs. 50.8%) and in the prevalence of smoking mothers (20.3% vs. 29.7%) and fathers (33.9% vs. 39.0%). Median UC concentration was 8.0ng/mL (interquartile range [IQR]: 2.0-21.8) before legislation onset and 8.7ng/mL (IQR: 2.0-24.3) afterwards. In the multivariable analysis, the smoking status of parents and smoking habits at home were statistically associated with the risk of SHS exposure and with UC concentrations in children. These findings indicate that the recent prohibition of smoking in enclosed public and workplaces in Spain has not been accompanied by a decline in the exposure to SHS among children, who continue to be adversely affected. There is a need to target smoking at home in order to avoid future adverse health effects in a population that has no choice in the acceptance or not of SHS exposure-derived risk.

Role of Environmental Factors in the Development of Pediatric Eosinophilic Esophagitis.

BACKGROUND: Despite accumulating data on the pathogenesis of eosinophilic esophagitis, not much is known about risk factors for the development of the disease. The role of factors such as smoking, breastfeeding, early antibiotic exposure and other factors that have been associated with other allergic diseases has not been well studied in children with eosinophilic esophagitis. AIM: To explore the role of environmental and medication exposures in the development of pediatric eosinophilic esophagitis. METHODS: We conducted a cross-sectional case-control study, utilizing a parent and child questionnaire and medical chart review. Urine cotinine levels, measured by high-performance liquid chromatography, were obtained as objective evidence for smoking exposure. RESULTS: One hundred and two children with eosinophilic esophagitis and 167 controls were recruited. The controls were mainly diagnosed with functional gastrointestinal disorders (33%) and gastroesophageal reflux disease (29%). Food allergy, specifically for peanuts and tree nuts, and allergy to pollen, tree, and grass were significantly higher among eosinophilic esophagitis children. Smoking exposure, both primary and secondary, was not associated with pediatric eosinophilic esophagitis when compared to controls (odds ratio 0.96, 95% confidence interval 0.58-1.59). Furthermore, early smoking exposure in the first year of life was higher among controls. Common accepted risk factors for allergy and atopy, such as breastfeeding practices, antibiotics exposure, animals' exposure, and others, were not found to be associated with eosinophilic esophagitis in our study. CONCLUSION: Common risk factors in other allergic and atopic conditions were not found to be associated with eosinophilic esophagitis.

Secondhand smoke exposure and urine cotinine concentrations by occupation among Korean workers: results from the 2008 Korea National Survey for Environmental Pollutants in the Human Body.

This study aimed to estimate the status of secondhand smoke (SHS) exposure through urine cotinine analysis among nonsmoking workers in Korea and to analyze factors affecting urine cotinine concentrations. Data were based on "The 2008 Korea National Survey for Environmental Pollutants in the Human Body," a cross-sectional study of the National Institute of Environmental Research of Korea. We selected 1448 nonsmoking adult workers from 200 localities to participate in this survey. Urine cotinine concentrations were analyzed using a gas chromatograph-mass selective detector. We calculated separate covariate-adjusted geometric means for socio-demographic variables for males, females, and total subjects by analysis of covariance (ANCOVA). Statistical analyses were performed using SPSS version 18.0 (SPSS Inc., Chicago, Ill.). The prevalence of self-reported exposure to SHS was 36.9%. The geometric mean (95% confidence interval) of urine cotinine concentrations among all participants was 16.50 (14.48-18.80) µg/L. Gender, living area, education, and SHS exposure showed significant differences in urine cotinine concentrations. The urine cotinine concentrations of farmworkers and blue-collar workers such as skilled agricultural, forestry, and fishery workers, and elementary occupations were higher than those of white-collar workers such as clerical support workers, technicians, and associate professionals. Such a high proportion of the population having high urine cotinine levels indicates widespread exposure to SHS among nonsmoking workers in Korea. Furthermore, the urine cotinine levels among nonsmoking workers exposed to SHS varied by occupation. The measured urine cotinine concentration is suggested to be a valuable indication of SHS exposure in Korea.

Evaluating the Impact of Chronic Care Model on Smoking Cessation: An Interventional Study.

BACKGROUND: This study aims to assess the effectiveness of the chronic care model (CCM) in helping primary healthcare workers quit smoking. The intervention involves implementing the CCM, which includes six key elements: the healthcare system, clinical care planning, clinical management information, self-management guidance, community resources, and decision-making. MATERIAL AND METHODS: The study is based on a population of 60 primary healthcare workers who smoke. The main outcome measure is smoking cessation, determined by cotinine levels in urine at the baseline, and at 6 and 12 months after the intervention. Other potential results include alterations in smoking-related behaviors and attitudes. Data analysis involves using descriptive statistics and inferential tests to determine the intervention's effectiveness in smoking cessation among primary healthcare workers. RESULTS:  The CCM is expected to have contributed to a substantial decrease in the smoking rate among primary healthcare workers. It is also seen that there is a great reduction in urine cotinine levels during the 12-month intervention period. Moreover, a positive shift in the smoking-related behaviors and attitudes of the participants is expected. CONCLUSION:  This study provides key data about the effectiveness of the CCM in helping primary healthcare workers stop smoking. This statement emphasizes the importance of considering socioeconomic factors in the design and implementation of smoking cessation interventions. This ensures that people of different incomes and social statuses have equal access to quitting smoking and achieve similar results.

Smoking cessation through nicotine replacement therapy for patients visiting the Dental College, Pune - A quasi-experimental study.

Background and Aim: Smoking leads to a very unhealthy lifestyle and has many deleterious effects on the body and surroundings. Studies have indicated that aiding contemplating smokers using behavior counseling and nicotine replacement therapy has shown positive results for abstaining from the habit. We aimed to assess and carry out smoking cessation for smokers using behavioral counseling, motivational interviewing, and nicotine replacement therapy (NRT) and assess their carbon monoxide (CO) cutoff level, Fagerstrom nicotine dependence test (FTND) scoring, and transtheoretical model (TTM) of change at baseline and 6 months, along with abstinence from the habit. Materials and Methods: CO cutoff, FTND scoring, and TTM of change were assessed at baseline and 6 months for smokers. Behavioral counseling with motivational interviewing was provided to the participants on the day of recruitment, and baseline data were recorded. All smokers included in the study were in the precontemplation and contemplation stages to quit smoking. Based on the frequency of smoking, NRT was prescribed to them in the form of a patch (21, 14, or 7 mg), only gums (2 mg), or a combination of both. Counseling was provided telephonically every month for 6 months. Urine cotinine assessment was carried out to verify the self-reported smoking status of the participants at the sixth month. Results: The CO cutoff, FTND scoring, and TTM of change showed statistically significant difference from baseline to the sixth month. Also, 20% (confidence interval [CI] 0.10-0.33) of participants who abstained from the habit were in the action and maintenance stages of change. Among 20% of participants, 16% (CI 0.10-0.36) of participants self-reported quitting within 6 months using combination therapy. Two percent (CI 0.00-0.40) each abstained by using nicotine gums and combination therapy of patch and gums, which was validated through urine cotinine. Conclusion: The cotinine test provided negative results, confirming the self-reported abstinence of 20% of participants, who were mostly male students and professionals in the age group of 20-40 years and those who used NRT. Nicotine patches provided the highest point prevalence of abstinence compared to gums and combination therapy.

Concordance assessment through comparison with urine cotinine: Does self-report adequately reflect passive smoking?

INTRODUCTION: There is a paucity of studies evaluating passive smoking (PS) by comparing self-report (SR) and biomarkers. Our study aimed to confirm whether SR could accurately reflect PS compared to biomarkers, a golden standard for assessing the exposure of non-smokers. METHODS: We used the 2014-2020 Korea National Health and Nutrition Examination Survey data and selected 29622 non-smokers aged >19 years as the study participants. The PS rate by SR was assessed during the last 7 days, and participants were interviewed to investigate their exposure at home, work, indoors, and in public places. In addition, participants having a limit of detection ≥0.5 ng/mL in urine cotinine (UC) was defined as the exposure group. All analyses reflected the weights of complex sampling. We first compared the rates of PS using biomarkers and SR, and then the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated based on biomarkers. RESULTS: PS exposure by UC was the highest (44.4%), and the exposure by SR was significantly lower (5.1-29.5%). Kappa and sensitivity in PS in the indoor home (HPS) were lower than those in indoor workplaces (WPS) and indoor public places (PPS). Moreover, overall sensitivity and PPV were lower, and specificity and NPV were relatively higher in accuracy. Lastly, the sensitivity was poor, and the specificity was relatively good, which means that measurement by SR would identify people who were actually exposed to PS as non-exposed. CONCLUSIONS: Despite exposure to PS, the use of the SR method is more likely to classify participants in the non-exposed group. Hence, to overcome measurement error in SR and reflect exposure in any place and setting, biomonitoring and SR should be performed.

[Situations of Passive Smoking by Urine Cotinine Levels and Recognition of Passive Smoking in High School Students -Effectiveness of Smoking Prevention Education Using a Video Made by High School Students].

We investigated a situation of passive smoking and its damaging effects among high school students. Urine cotinine concentration was measured and quantified. Additionally, we evaluated the awareness of passive smoking and smoking regulations in high school students, and the educational effect on passive smoking using a questionnaire survey and educational videos produced by high school students. We conducted a self-reporting questionnaire survey with high school students before and after watching the video produced by the high school students. We gathered the scores of the Kano Social Nicotine Dependence Questionnaire (KTSND) and awareness of smoking restrictions. Consent was obtained through the questionnaire before watching the video and collecting urine samples. Urine cotinine concentrations from 54 samples were evaluated and indicated within the low value. The KTSND score significantly decreased for those who responded to both questionnaires, after watching the video. Furthermore, analysis of the KTSND questionnaire items showed a significant decrease in scores for lifestyle, stress, and smoking location. This suggests that the video produced in this study has a certain amount of educational effect on passive smoking and that the student-led educational method is effective. The survey using the KTSND revealed that there were some students who were not exposed to passive smoking, but instead had high smoking tolerance. Going forward, it will be necessary to promote education on passive smoking and smoking prevention by incorporating the video lecture and urine cotinine concentration was measured, as in this study, to encourage behavior that decreases passive smoking among high school students.

Monthly Motivational Interview Counseling and Nicotine Replacement Therapy for Smoking Parents of Pediatric Patients: A Randomized Controlled Trial.

Background: Parental smoking is the dominant source of passive smoke exposure in the pediatric population. The current randomized controlled trial (RCT) study aimed to evaluate the effectiveness of a multi-component smoking reduction intervention in parental smoking reduction and children's environmental tobacco smoke exposure reduction in clinical settings. Methods: A single-blinded, 6-month randomized controlled trial recruited smoking parents (N = 210) of children who attended the pediatric wards or clinics at the Prince of Wales Hospital. Participants allocated to the intervention group (n = 105) received monthly motivational interviews on smoking reduction with emphasis on health hazards related to children's passive smoke exposure, 8-week nicotine replacement therapy, and referral to smoking cessation service if the parents preferred. The control group (n = 105) received simple verbal advice on smoking cessation. Primary outcomes were parental urine cotinine validated and self-reported ≥50% smoking reduction rates at 6 months. Results: Smoking parents in the intervention group had significantly more biochemically validated ≥50% smoking reduction than the control: 27.1 vs. 10.0% (OR = 3.34, 95% CI: 1.16-9.62, P = 0.02). The rate of self-reported ≥50% smoking reduction was also significantly higher in the intervention group than the control: 51.9 vs. 20.2% (OR = 4.40, 95% CI: 2.38-8.12, P < 0.001). For secondary outcomes, the rate of parental self-reported smoking cessation was higher in the intervention arm: 10.5 vs. 1.0% (OR = 12.17, 95% CI: 1.54-96.07, P < 0.001), however, no differences were detected in biochemically validated cessation and changes in children's passive smoke exposure between the groups. Conclusion: Monthly smoking reduction counseling together with nicotine replacement therapy is more effective than simple verbal cessation advice in the smoking reduction for parents of pediatric patients. However, this study did not demonstrate differences in smoking cessation or reduction in children's passive smoke exposure with a 6-month follow-up. Achievement of a smoke-free environment remains challenging. Trial Registration: Clinicaltrials.gov, identifier: NCT03879889.

Secondhand tobacco smoke exposure, urine cotinine, and risk of incident atrial fibrillation: The multi-ethnic study of atherosclerosis.

BACKGROUND: Secondhand tobacco smoke (SHS) exposure may reduce heart rate variability and lead to atrial fibrillation (AF); however prior study findings have not been confirmed using objective measures for both SHS and AF events. METHODS: We prospectively examined the association between SHS exposure and incident AF in 5731 participants, ages of 45-84 years and free of known AF and other cardiovascular diseases (CVD) at baseline (2000-2002), who were followed through 2015 in the Multi-Ethnic Study of Atherosclerosis (MESA). SHS weekly exposure time was identified by self-report. Urine cotinine was collected in a cohort subset of 3237 current non-smoking cohort participants. AF events were identified using Medicare claims, hospital records, and 12­lead electrocardiographic findings. A multivariable Cox proportional hazards regression analysis was used with simultaneous adjustment for demographic factors, educational level, health insurance status, active smoking status, tobacco pack-years, traditional CVD risk factors, depressive symptoms and medications. RESULTS: During a median follow-up of 14.0 years, 856 and 452 AF events were identified in the overall and the cohort subset, respectively. No association of SHS exposure time or urine cotinine with incident AF was observed. However, a higher AF risk with greater urine cotinine (8.53-442.0 ng/mL) compared with lower urine cotinine (≤7.07 ng/mL) was observed in never smokers [hazard ratios (HR) and 95% confidence intervals: 1.60 (1.16, 2.19)], but not in former smokers [HR: 0.88 (0.63, 1.23)] (p-value for multiplicative interaction: 0.009 and for additive interaction: 0.017, respectively). CONCLUSION: Objectively measured greater SHS exposure expressed by urine cotinine might be associated with 1.6-fold higher risk of incident AF in never smokers.

Association between urine cotinine and depressive symptoms in non-smokers: National representative sample in Korea.

BACKGROUND: Secondhand smoke (SHS) exposure is known to have negative effects on mental as well as physical health. However, the association between SHS and mental health problems has not been assessed in non-smokers. To evaluate the association of exposure to tobacco smoke and depressive symptoms, and that of the prevalence of having depressive symptoms and urinary cotinine (UCo) concentrations in non-exposed subjects. METHODS: Data was extracted from the Korea National Health and Nutrition Examination Survey (KNHANES). Depressive symptoms were determined based on a patient's overall score on the Patient Health Questionnaire (PHQ)-9, and SHS exposure was evaluated using self-reported data and UCo concentration. Overall, 13,219 non-smokers, ≥ 19 years were included in the study. Multinomial logistic regression analysis was conducted to identify factors related to depressive symptoms; independent t-test was conducted to confirm the differences in UCo concentration according to the prevalence of depression. RESULTS: Among the non-exposure groups, 2.0% of the males and 5.6% of the females showed depressive symptoms. Lower social-economic status, higher UCo concentration, and SHS exposure increased the prevalence of depressive symptoms. The UCo concentration of females with depressive symptoms was significantly higher than those of females without depressive symptoms. LIMITATIONS: This study only demonstrated an association between SHS exposure and depression, not the causal effects, because of the cross-sectional study design. CONCLUSION: SHS exposure and depressive symptoms are correlated. The association was also confirmed by evaluating the UCo concentration of those who were not exposed to SHS based on self-reported data.

Association between Self-Reported Survey Measures and Biomarkers of Second-Hand Tobacco Smoke Exposure in Non-Smoking Pregnant Women.

Second-hand tobacco smoke (SHS) causes adverse health outcomes in adults. Further studies are needed to evaluate psychosocial SHS exposure measures in comparison to SHS exposure biomarkers, particularly in pregnant women. This study aimed to compare self-reported SHS exposure to urinary cotinine levels in pregnant women. A cross-sectional correlation design was conducted using a convenience sample of 70 non-smoking pregnant women. Measures included self-reported questionnaires and laboratory confirmation of cotinine levels in the urinary samples. Multiple regression analysis was used to assess the correlation after controlling for potential confounding variables. The average level of urinary cotinine among non-smoking pregnant women was 6.77 ng/mL. Medium-strength correlations were found among psychosocial SHS exposure measures and urine cotinine levels. Questions regarding 'instances of smoking in front of the individual' and 'subjective perceived frequency of SHS exposure in past 7 days' are feasible items for pregnant women in clinics (particularly the first question). Hence, we suggest that these simple questions should be used to assist pregnant women in reducing the harm associated with SHS exposure.

Validity assessment of self-reported smoking status in firefighters using the urine cotinine test.

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.

Estimates of cutoffs with specificities and sensitivities for urine cotinine and hydroxycotinine for US adults aged ≥ 20 years to classify smokers and nonsmokers.

Data for urine cotinine and hydroxycotinine became available for the first time in the 2013-2014 cycle of the National Health and Nutrition Examination Survey administered by the US Centers for Disease Control and Prevention. Cutoffs to classify smokers and nonsmokers for both cotinine and hydroxycotinine for US adults aged ≥ 20 years were developed by using receiver operating characteristic curve methodology. The optimality criterion used to determine cutoffs simultaneously maximized both specificity and sensitivity. Cutoffs were determined for the total population, males, females, non-Hispanic whites, non-Hispanic blacks, Hispanics, and non-Hispanic Asians. Cutoffs for both cotinine and hydroxycotinine were determined with a minimum sensitivity of 95.5% and with a minimum specificity of 95.4%. For the total population, cutoff for urine cotinine was 91.7 ng/mL estimated with a specificity as well as a sensitivity of 97.1%. The cutoff for the total population for urine hydroxycotinine was 128.0 ng/mL estimated with a specificity as well as a sensitivity of 96.5%. The order in which cutoffs were observed for cotinine was non-Hispanic blacks (283.0 ng/mL) > non-Hispanic whites (111.0 ng/mL) > males (109.0 ng/mL) > females (91.7 ng/mL) > total population (91.7 ng/mL) > Hispanics (20.8 ng/mL) > non-Hispanic Asians (7.39 ng/mL). The order in which cutoffs were observed for hydroxycotinine was non-Hispanic blacks (530.0 ng/mL) > non-Hispanic whites (180.0 ng/mL) > females (97.0 ng/mL) > total population (96.5 ng/mL) > males (95.9 ng/mL) > Hispanics (20.6 ng/mL) > non-Hispanic Asians (13.8 ng/mL). Thus, the largest cutoffs were observed for non-Hispanic blacks and the lowest cutoffs were observed for non-Hispanic Asians.

Self-reported smoking among adolescents: How accurate is it with the urine cotinine strip test?

BACKGROUND & OBJECTIVE: In the local setting, the prevalence of smoking among adolescents varies, as it is based only on self-reporting without biomarker validation. The objective of the present study was to determine the accuracy of self-reported smoking among adolescents as compared to that of the urine cotinine strip test. METHODS: We performed a cross-sectional study of 314 adolescents aged 16 years from February 2015 to April 2015 in Putrajaya, Malaysia. The accuracy of self-reporting was assessed using a data collection sheet and was validated by the urine cotinine strip test. Three schools were chosen by the simple random method, where all Form 4 students constituted the sample unit. The kappa statistic was used for determining agreement between self-reporting and urine cotinine strip testing. RESULTS: There was a substantial agreement between self-reporting and the urine cotinine strip test (kappa = 0.757, 95% confidence interval [CI]: 0.63, 0.88); there was 95.86% overall agreement. The prevalence of self-reported smoking was 8% (95% CI: 7.47, 8.53) and that of urine cotinine strip testing was 10.8% (95% CI: 10.20, 11.41). There was a discrepancy with the results of the urine cotinine strip test in 8% of self-reported smokers and 3.8% of self-reported nonsmokers. Self-reporting had 67.6% sensitivity and 99.3% specificity as compared to those of urine cotinine strip testing and had 92% positive predictive value and 96.2% negative predictive value. CONCLUSION: Self-reporting can be used to assess smoking status but should be used with care among adolescents. Urine cotinine strip test validation of self-reporting enables the measurement of the true prevalence of smoking among adolescents.

Differences between the effects of conventional cigarettes, e-cigarettes and dual product use on urine cotinine levels.

INTRODUCTION: The goal of this study was to evaluate the differences in urine cotinine (UC) concentration based on the use of conventional cigarettes, e-cigarettes (ECs), and dual product use, and determine the use of ECs in the real world. METHODS: In total, 15099 subjects were classified into non-smokers, cigarette smokers (c-smokers), e-cigarette smokers (e-smokers), and dual users, and their UC (a classical biomarker of smoking) values were compared. Analysis of covariance (ANCOVA) was performed after adjusting for age, sex and job status to analyze the differences in UC concentration in relation to type of smoking. The reasons for using ECs and the experience of cigarette use before using ECs were analyzed. RESULTS: Of the 15099 people, 76.4% were non-smokers, 20.9% c-smokers, 2.3% dual users, and 0.4% were e-smokers. There were significant differences in UC concentration among the groups (p<0.001). The geometric mean (GM) UC concentration was 4.45 ng/mL. UC concentration was the highest among dual users (GM: 1030.5, median: 1258.9 ng/mL), followed by c-smokers (GM: 842.5, median: 1163.0 ng/mL), e-smokers (GM: 119.5, median: 309.7 ng/mL), and non-smokers (GM: 0.8, median: 0.8 ng/mL). Among the EC users, the rate of using ECs for health or social convenience was 81.9%. Among e-smokers, 11.4% had never smoked previously. CONCLUSIONS: The UC concentration was the highest among dual users. However, for the female population, the UC concentration was the highest among e-smokers. The vast majority of EC users were dual users. In addition, there were no differences in the frequency of cigarette smoking between the dual user and c-smoker groups. Consequently, EC use did not lead to a decrease in cigarette use, but did lead to an increase in UC concentration. Therefore, in the real world, dual users have higher cotinine levels than the other groups, which could indicate that they take more nicotine by cigarettes or ECs, or are more addicted than others.