The relationship between nicotine dependence scores and biomarkers of exposure in adult cigarette smokers

Background: Tobacco dependence is a multidimensional phenomenon. The Fagerström Test for Nicotine Dependence (FTND) is a widely administered six-item questionnaire used as a measure of nicotine dependence. It has been suggested that this test may not represent the entire spectrum of factors related to dependence. Also the relationship of this test with biomarkers of exposure to cigarette smoke has not been extensively studied. Methods: Data from a multi-center, cross-sectional, ambulatory study of US adult smokers (the Total Exposure Study, TES) was analyzed. The FTND score and a number of additional questions related to smoking behavior, from an adult smoker questionnaire (ASQ) completed by 3585 adult smokers in the TES were analyzed. The 24-h urine nicotine equivalents, serum cotinine and blood carboxyhemoglobin were measured as biomarkers of exposure (BOE) to nicotine and carbon monoxide. Cigarette butts returned were collected during the 24-h urine collection period. Results: The FTND showed moderate correlations with BOE, while selected questions from ASQ although statistically significant, had weaker correlations. FTND scores showed substantially weaker correlations without the question about cigarettes smoked per day (CPD). CPD and time to first cigarette (TTFC) had the most impact on BOE. Conclusion: Additional questions from ASQ did not appear to contribute towards refining the FTND test. The correlation of the FTND scores with nicotine and carbon monoxide seems to be primarily driven by CPD. CPD and TTFC were the most important factors correlating with exposure.     

Time-varying effects of smoking quantity and nicotine dependence on adolescent smoking regularity

Background

Little is known about time-varying effects of smoking quantity and nicotine dependence on the regularity of adolescent smoking behavior.

Methods

The sample was drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns Study which followed adolescent smokers over 5 assessment waves spanning 48 months. Participants included former experimenters (smoked <100 cigarettes/lifetime but did not smoke in past 90 days), recent experimenters (smoked <100 cigarettes/lifetime and smoked in past 90 days), and current smokers (smoked >100 cigarettes/lifetime and smoked in past 30 days). Mixed-effects regression models were run to examine the time-varying effects of smoking quantity and nicotine dependence on regularity of smoking behavior, as measured by number of days smoked.

Results

Smoking quantity and nicotine dependence were each found to be significantly associated with regularity of adolescent smoking and the size of each effect exhibited significant variation over time. The effect of smoking quantity decreased across time for each smoking group, while the effect of nicotine dependence increased across time for former and recent experimenters. By the 48-month follow-up, the effects of smoking quantity and nicotine dependence had each stabilized across groups.

Conclusions

This study reveals that smoking quantity and nicotine dependence are not static risk factors for the development of more regular smoking patterns. At low levels of smoking when nicotine dependence symptoms are less common, smoking quantity is a stronger predictor of increased regularity of smoking, while for more experienced smokers, nicotine dependence predicts further increases in regularity.     

Effects of abstinence and smoking on information processing in adolescent smokers

RATIONALE: Although adolescent smokers appear to display some of the hallmark features of dependence, the biological and behavioral effects of smoking in this population are poorly understood. OBJECTIVES: This study aimed to define empirically the effects of abstinence and smoking in adolescent smokers, using indices validated in adult smokers. METHODS: Subjects were 16 young novice smokers (five male, 11 female), ages 14-18 years. A modified Stroop task measured the ability to inhibit attention to smoking-related cues; the classic Stroop task measured the ability to inhibit a pre-potent response (i.e. reading a word); a rapid information processing (RIP) task measured vigilance. RESULTS: Abstinence increased and smoking decreased the intrusiveness of smoking cues. Parallel effects were seen in commission errors on the RIP task. These effects were restricted to heavier smokers (>11 cigarettes/day). Subjective withdrawal effects predicted the intrusiveness of smoking words during abstinence. The number of cigarettes smoked per day predicted the beneficial effect of smoking on the classic as well as modified Stroop tasks. The physiological effects of abstinence and smoking predicted RIP performance. CONCLUSIONS: Abstinence impairs and smoking improves inhibitory information processing in young novice smokers in a manner similar to adult smokers. Daily frequency of smoking is a critical moderator of these effects.     

Alcohol use as a signal for sensitivity to nicotine dependence among recent onset smokers

Objective

This study evaluated the association between alcohol use, abuse and dependence and cigarette smoking to determine whether alcohol may signal greater sensitivity to nicotine dependence at very low levels of smoking.

Method

Data were drawn from five annual National Surveys on Drug Use and Health and included individuals age 12 to 21 who reported first exposure to smoking within the past two years and smoking at least once in the past month.

Results

Both alcohol abuse and alcohol dependence were associated with increased likelihood of symptoms that seem to tap tolerance for nicotine. These included items such as “the amount you smoke has increased”; “needing to smoke a lot more now in order to be satisfied”; and “smoking much more before starting to feel anything”. Alcohol dependence, but not abuse was associated with the remaining symptoms, “after not smoking for a while, needing to smoke to feel less restless and irritable”; “craving cigarettes after not smoking for a while”; and “worrying about running out of cigarettes”. All associations were not better accounted for by either alcohol use or amount smoked.

Conclusion

If causally associated, treatment of alcohol-use disorders may prevent or reduce the early emergence of nicotine dependence symptoms among new smokers, very early in the smoking uptake process. If instead alcohol disorders are a signal of sensitivity for nicotine dependence best accounted for by a third variable, then adolescents with alcohol dependence and/or abuse during early exposures to smoking represents an important subgroup that may benefit from interventions directly targeting this association.     

Risk factors for adolescent smoking: parental smoking and the mediating role of nicotine dependence

Background

Parental smoking and early-emerging nicotine dependence symptoms are well-documented risk factors for adolescent smoking. However, very little is known about the mediating pathways through which these risk factors may act, or whether parental smoking may cause or signal early-emerging nicotine dependence symptoms.

Methods

Data were drawn from the longitudinal Social and Emotional Contexts of Adolescent Smoking Patterns Study. Adolescents who had smoked under 100 cigarettes in their lifetime (n = 594; low-exposure group) and adolescents who had smoked over 100 cigarettes, but fewer than 5 cigarettes per day (n = 152) were included in the analyses. Path analysis was performed on longitudinal data to investigate the association between parental smoking and smoking frequency at the 48 months follow-up, both directly and through mediating variables of smoking frequency, smoking quantity, and nicotine dependence.

Results

Father's smoking was associated with higher adolescent nicotine dependence scores at the baseline assessment wave. Structural equation modeling revealed that mother's smoking at baseline was associated with adolescent's smoking frequency at the 48-month follow-up, and its effect was partially mediated by both smoking frequency and nicotine dependence among low-exposure adolescent smokers.

Conclusions

Parental smoking is a risk factor for future smoking in low-exposure adolescent smokers, above and beyond the risks posed by smoking behavior and nicotine dependence. Moreover, parental smoking is associated with early-onset nicotine dependence in low-exposure adolescent smokers. As an easily measureable risk factor, parent smoking status can be used to identify and intervene with novice adolescent smokers who are at high risk for chronic smoking behavior.     

Dependence on the nicotine gum in former smokers

We conducted an Internet survey in 2004–2007 in 526 daily users of the nicotine gum, to assess use of, and dependence on the nicotine gum in former smokers. We used modified versions of the Nicotine Dependence Syndrome Scale (NDSS-G), the Cigarette Dependence Scale (CDS-G) and the Fagerström Test (FTND-G). After 30 days, 155 participants (29%) indicated their gum use. Higher dependence on the gum predicted a lower chance of stopping using it at follow-up (odds ratio = 0.36 for each standard deviation unit on CDS-G, p = 0.001). More long-term (> 3 months) than short-term (< = 3 months) users of the gum agreed with: “I use the nicotine gum because I am addicted to it” (83% vs. 7%, p < .001), and fewer long-term users reported that they used the gum to avoid relapsing to smoking (42% vs. 92%, p < .001). Long-term users had higher ratings of dependence on the gum than short-term users, as assessed with NDSS-Gum, CDS-Gum and FTND-Gum (all p < .001). Most long-term users reported symptoms of dependence on the nicotine gum. Lower levels of dependence on the gum predicted cessation of gum use. However, long term use of the nicotine gum has no known serious adverse consequence, and may be beneficial if it prevents late relapse.     

Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers

Introduction

Smoking family predicts adolescent smoking, but whether the level of nicotine addiction is affected by exposure to secondhand smoke (SHS) is unclear. We investigated the associations of smoking family and SHS exposure at home with morning smoking and heavier smoking among Chinese adolescent smokers.

Methods

In a school-based anonymous survey, 2182 adolescent smokers reported their smoking behaviors, smoking status of family members and peers, and SHS exposure at home and outside home in the past 7 days. Families with one or more smoking members (excluding the subject) were classified as smoking families and otherwise as non-smoking families. Smoking or wanting to smoke first thing in the morning (morning smoking), and consuming more cigarettes (heavier smoking) denoted higher levels of nicotine addiction. Regression analysis yielded adjusted odds ratios (AORs) for morning smoking and β-coefficients for heavier smoking adjusting for potential confounders.

Results

Living with siblings and other co-residing family members who smoked was significantly associated with morning smoking and heavier smoking. Compared with non-smoking families without SHS exposure at home, the AORs (95% CI) for morning smoking were 0.99 (0.76 to 1.29) for 0 day/week, 1.19 (0.95 to 1.50) for 1–3 days/week, 1.76 (1.41 to 2.21) for 4–7 days/week (p for trend < 0.001) and 1.50 (1.23 to 1.83) for any days/week of SHS exposure at home in smoking families. Similarly, 4–6 days/week of SHS exposure at home significantly predicted heavier smoking.

Conclusion

Living with smoking family members and SHS exposure at home are associated with nicotine addiction in Chinese adolescent smokers.     

Respiratory retention of nicotine and urinary excretion of nicotine and its five major metabolites in adult male smokers

Urinary excretion of nicotine and its five major metabolites (nicotine-N-glucuronide, cotinine, cotinine-N-glucuronide, trans-3'-hydroxycotinine, and trans-3'-hydroxycotinine-O-glucuronide), expressed as nicotine equivalents (NE), has been used as a biomarker of smoking-related nicotine exposure. In this open-label, single center study, we investigated the relationship between nicotine retention from smoking and urinary excretion of NE in adult smokers. After a 4-day washout period, 16 adult male smokers smoked 6 cigarettes per day for four consecutive days according to three predefined smoking patterns: no inhalation (Pattern A), normal inhalation (Pattern B), and deep inhalation (Pattern C). The amount of nicotine retained in the respiratory tract during smoking was estimated from the difference between the amounts of nicotine delivered and exhaled. The daily excretion of urinary NE was measured in 24h urine samples by LC-MS/MS. The mean (+/-S.D.) amount of nicotine retained was 0.126+/-0.167, 0.960+/-0.214, and 1.070+/-0.223mg/cig for Patterns A, B, and C, respectively. The mean (+/-S.D.) relative retention (the amount retained relative to the amount delivered) was 11.2+/-14.7%, 98.0+/-1.6%, and 99.6+/-0.3% for Patterns A, B, and C, respectively. On the fourth day of smoking, an average of 86+/-20% of the total daily amount of retained nicotine was recovered as NE in 24h urine. Nicotine equivalents was treated as a single component and the data was described by a first-order elimination pharmacokinetic model which assumed instantaneous input and distribution. Based on this model, the elimination half-life of NE was 19.4+/-2.6h, and the NE excretion had reached approximately 96% of the steady state levels by Day 4. Our results suggest that most of the nicotine inhaled from a cigarette is retained (> or =98%) in the lung, and at steady state, daily urine NE excretion reflects approximately 90% of the retained nicotine dose from cigarette smoking.     

The relationship between impulsivity,risk-taking propensity and nicotine dependence among older adolescent smokers

Impulsivity and risk-taking propensity are neurobehavioral traits that reliably distinguish between smoking and non-smoking adults. However, how these traits relate to smoking quantity and nicotine dependence among older adolescent smokers is unclear. The current study examined impulsivity and risk-taking propensity in relation to smoking behavior and nicotine dependence among current older adolescent smokers (age 16–20 years; N = 107). Participants completed the Barratt Impulsiveness Scale‐11 (BIS-11), the Balloon Analogue Risk Task (BART), and self-report measures of smoking behavior and nicotine dependence. Results indicated a significant positive relationship between nicotine dependence and the Attention subscale (β = .20, t = 2.07, p < .05) and the Non-planning subscale (β = .19, t = 1.92, p < .06) of the BIS-11. Contrary to expectation, the results also indicated a significant negative relationship between performance on the BART and nicotine dependence (β = − .19, t = − 2.18, p < .05), such that greater risk-taking propensity was associated with less dependence. These data suggest that impulsivity and risk-taking propensity are related to older adolescent smoking but are separable traits with distinguishable associations with nicotine dependence among adolescents. These findings support the notion that impulsivity is related to heightened nicotine dependence, but suggest that the relationship between risk-taking propensity and nicotine dependence is more ambiguous and warrants further investigation.     

Measuring nicotine dependence among smokeless tobacco users

The objective of this study was to assess the concurrent validity of the FTQ-ST and the DIS-IV diagnosis of nicotine dependence among 68 adult ST users enrolled in a randomized, controlled clinical trial of bupropion SR. FTQ-ST scores were not found to differ between those with and without a current DIS-IV diagnosis of nicotine dependence (7.4+/-2.1 vs. 6.8+/-2.8, P=0.325). For all possible FTQ-ST cutoff scores, the observed agreement between the FTQ-ST and the DIS-IV was not found to be different from that expected due to chance. FTQ-ST total scores were positively correlated with serum cotinine (Spearman's r=0.40, P<0.001), amount of tobacco used (r=0.51 and r=0.41 for average dips/chews per day; average tins/pouches per week, respectively, P<0.001), and a reduced likelihood of abstinence at 3 months (OR=0.76, 95% C.I. 0.61-0.96; P=0.019). Participants meeting DIS-IV criteria had lower cotinine concentrations than those without this diagnosis (411+/-263 ng/ml vs. 493+/-246 ng/ml; P=0.042). Poor concordance was observed between the FTQ-ST and the DIS-IV in the assessment of nicotine dependence in ST users.     

A systematic review of the Diagnostic and Statistical Manual diagnostic criteria for nicotine dependence

The Diagnostic and Statistical Manual diagnostic criteria for nicotine dependence (DSM-ND) are based on the proposition that dependence is a syndrome that can be diagnosed only when a minimum of 3 of the 7 proscribed features are present. The DSM-ND criteria are an accepted research measure, but the validity of these criteria has not been subjected to a systematic evaluation.     

Shorter time to first cigarette of the day in menthol adolescent cigarette smokers

Menthol smoking is thought to contribute to the addictiveness of smoking. Given the high prevalence of menthol smoking among youth, the aim of the current analysis was to examine differences in consumption and tobacco dependence, including smoking urgency among menthol and non-menthol adolescent smokers. Data for the current analysis were collected from telephone interviews with adolescent smokers applying to a cessation treatment study. Of 572 adolescent smokers (mean age=15.6+/-1.6 years; 55.1% female; 46.9% African American, 48.2% European American), 531 smoked menthol cigarettes and 41 smoked non-menthol as their usual brand. Analysis using Fisher's Exact (one-tailed) Test revealed that menthol smokers had a significantly shorter time to first (TTF) cigarette of the day compared to non-menthol smokers (smoking within the first 5 min of the day, 45% vs. 29%, respectively; p<0.04). Independent t tests revealed no significant difference in number of cigarettes per day (CPD) (mean=12.2+/-8.5 vs. 11.4+/-8.8; p<0.28) or Fagerstrom Test for Nicotine Dependence (FTND) scores (3.4+/-1.4 vs. 3.2+/-1.3; p<0.23). While preliminary, our findings suggest greater smoking urgency among menthol compared to non-menthol adolescent cessation-treatment seekers. Further study in a broader sample of adolescent smokers is warranted to elucidate the mechanisms underlying the effects of menthol smoking for youths.     

Symptoms of alcohol dependence and smoking initiation and persistence: A longitudinal study among US adults

Background

A large number of adults report symptoms of, but do not meet diagnostic criteria for, an alcohol use disorder. Yet, little is known about the relationship between symptoms of alcohol use disorders and the initiation and persistence of smoking. This study prospectively examines the relationship between having 1–2 symptoms of alcohol dependence (without abuse) and smoking initiation and persistence as well as nicotine dependence over a 3-year period among adults in the United States.

Methods

Data were drawn from Wave 1 (2001–2002) and Wave 2 (2004–2005) of the National Epidemiologic Survey on Alcohol and Related Conditions. Relationships between Wave 1 symptoms of alcohol dependence, alcohol abuse, and alcohol dependence and initiation and persistence of cigarette smoking and nicotine dependence at Wave 2 were examined using logistic regression analyses. Analyses were adjusted for demographics, mood and anxiety disorders.

Results

Symptoms of alcohol dependence were associated with smoking initiation at Wave 2. There was no association between symptoms of alcohol dependence and smoking persistence. Symptoms of alcohol dependence predicted incident and persistent nicotine dependence. Findings persisted after adjusting for demographic characteristics and mood/anxiety disorders.

Conclusions

Even 1–2 symptoms of alcohol dependence are associated with increased vulnerability to smoking initiation and onset and persistence of nicotine dependence at a similar strength as alcohol use disorders. Efforts at smoking cessation must address problematic alcohol use, even at the subclinical level, in order to improve efficacy.     

Exposure to chronic intermittent nicotine vapor induces nicotine dependence

Animal models of drug exposure are important tools for the study of the neurobiological mechanisms of nicotine dependence and as preclinical models for medication development. There are few non-invasive animal models of nicotine exposure and currently there is no known animal model of second-hand exposure to nicotine. We hypothesized that chronic administration of nicotine vapors would produce blood levels of nicotine in rodents that are clinically relevant to those observed in human smoking and that rodents exposed to nicotine vapors would develop dependence to nicotine. We developed a system that vaporizes nicotine in the air in a stable, reliable and consistent manner. Intermittent exposure to nicotine vapor (0.2 mg/m³) for 8 or 14 h per day for 7 days produced a concentration of nicotine in the blood of 22 ng/mL. Sixteen hours after removal from nicotine vapors, rats showed significant somatic withdrawal signs precipitated by mecamylamine (1.5 mg/kg). These results provide a new rodent model of nicotine dependence using vapor administration that produces consistent levels of nicotine in the blood that are relevant for both heavy smoking and second-hand smoking, using a non-invasive technique that mimics the intermittent aspect and route of administration in humans.     

Evidence for greater cue reactivity among low-dependent vs. high-dependent smokers

Introduction

Cue reactivity paradigms are well-established laboratory procedures used to examine subjective craving in response to substance-related cues. For smokers, the relationship between nicotine dependence and cue reactivity has not been clearly established. The main aim of the present study was to further examine this relationship.

Methods

Participants (N = 90) were between the ages 18–40 and smoked ≥10 cigarettes per day. Average nicotine dependence (Fagerström Test for Nicotine Dependence; FTND) at baseline was 4.9 (SD = 2.1). Participants completed four cue reactivity sessions consisting of two in vivo cues (smoking and neutral) and two affective imagery cues (stressful and relaxed), all counterbalanced. Craving in response to cues was assessed following each cue exposure using the Questionnaire of Smoking Urges-Brief (QSU-B). Differential cue reactivity was operationally defined as the difference in QSU scores between the smoking and neutral cues, and between the stressful and relaxed cues.

Results

Nicotine dependence was significantly and negatively associated with differential cue reactivity scores in regard to hedonic craving (QSU factor 1) for both in vivo and imagery cues, such that those who had low FTND scores demonstrated greater differential cue reactivity than those with higher FTND scores (β = −.082; p = .037; β = −.101; p = .023, respectively). Similar trends were found for the Total QSU and for negative reinforcement craving (QSU factor 2), but did not reach statistical significance.

Discussion

Under partially sated conditions, less dependent smokers may be more differentially cue reactive to smoking cues as compared to heavily dependent smokers. These findings offer methodological and interpretative implications for cue reactivity studies.     

A measure of nicotine dependence for smokeless tobacco users

The objective of the present study was to examine the properties of a modification of the Fagerström Test of Nicotine Dependence in a large sample of smokeless tobacco (ST) users. The subjects for this study included 256 males who were recruited for a tobacco cessation intervention that involved a visit with a dentist and advice to quit smoking during the exam. At baseline, the modified dependence scale was administered to the participants and a saliva sample was collected to measure cotinine. The correlation between the total score and salivary cotinine was moderate among the ST only users (r = 0.34), whereas it was lower (r = 0.19) among the ST + cigarette users. Among ST only users, the coefficient alpha was 0.40; however it was considerably higher among the ST + cigarettes group (alpha = 0.61). In both cases, the coefficient alpha was lower than the recommended value of 0.70. Future research should focus on refining questionnaires that more precisely measure nicotine dependence in smokeless tobacco users.     

Adolescent nicotine dependence symptom profiles and risk for future daily smoking

Recent research on adolescent smokers suggests that there are important differences in the types of nicotine dependence (ND) symptoms that emerge and different patterns of ND symptoms. The purpose of this study was to use data from the longitudinal Social and Emotional Contexts of Adolescent Smoking Patterns Study to identify latent subgroups of adolescent experimental and nondaily smokers varying in number and types of endorsed ND symptoms. Profiles were identified using baseline level of smoking, individual patterns of ND symptoms and other ND risk factors. Discrete time survival analysis was used to examine profile differences in probability of becoming daily smokers 48 months later. Four distinct subgroups of smokers with different patterns of smoking behavior, ND symptoms, and alcohol and other substance use emerged. Heavier smoking adolescents with high symptom endorsement, particularly the need to smoke in the morning, were most likely to become daily smokers 48 months later. A subgroup of social smokers had high smoking exposure and symptom endorsement (except need to smoke in the morning), and high levels of other substance use. Despite lower rates of smoking frequency and quantity compared to the heavier smoking class, 36% of these adolescents smoked daily by 48 months, with a steeper decline in survival rates compared to other lighter smoking classes. Morning smoking symptoms and symptoms prioritizing smoking (i.e., choosing to spend money on cigarettes instead of lunch or smoking when ill or where smoking is forbidden) might quickly identify adolescent non-daily smokers with more severe dependence and higher risk for daily smoking. A focus on skills for avoiding social situations involving use of alcohol and other drugs and reducing peer smoking influences may be an important focus for reducing smoking and other substance use among social smokers.     

Dexamethasone attenuation of the cortisol response to nicotine in smokers

The effect of corticosteroids upon the cortisol response to nicotine from smoking was investigated in five heavy smokers. Corticosteroid activity was manipulated by administering dexamethasone, a synthetic glucocortoicoid (1 mg orally, 14 h before), in a doubleblind, placebo-controlled procedure. Testing took place in the middle of the day and involved the smoking of two high-nicotine (2.87 mg) research cigarettes over a 15-min period. The dexamethasone condition was characterized by a pronounced suppression of baseline plasma cortisol, as expected, and by a significant dampening of the cortisol response to nicotine, indicating diminished sensitivity to nicotine under conditions of enhanced corticosteroid activity.     

Carbon monoxide feedback in a motivational decision support system for nicotine dependence among smokers with severe mental illnesses

Health concerns are common reasons for wanting to quit smoking among smokers with mental illnesses. Motivational interventions have used feedback from a carbon monoxide monitor to increase awareness of health concerns, but this device is not commonly available. Whether brief motivational interventions can be effective without this feedback is unknown. Using a randomized controlled trial, this study tested the effect of carbon monoxide feedback within a brief, multi-component, computerized motivational intervention among 124 smokers with schizophrenia or mood disorders. The main outcome was initiating cessation treatment over two months. Although participants in the carbon monoxide group increased their knowledge about the carbon monoxide, (χ² = 6.97, df = 1, p = .008), the main and secondary outcomes did not differ significantly between groups. Overall, 32% of participants initiated treatment. This study suggests that a computerized motivational decision support system can lead users to initiate cessation treatment, and that carbon monoxide feedback is not a necessary component.     

Factors affecting exposure to nicotine and carbon monoxide in adult cigarette smokers

Exposure to cigarette smoke among smokers is highly variable. This variability has been attributed to differences in smoking behavior as measured by smoking topography, as well as other behavioral and subjective aspects of smoking. The objective of this study was to determine the factors affecting smoke exposure as estimated by biomarkers of exposure to nicotine and carbon monoxide (CO). In a multi-center cross-sectional study of 3585 adult smokers and 1077 adult nonsmokers, exposure to nicotine and CO was estimated by 24 h urinary excretion of nicotine and five of its metabolites and by blood carboxyhemoglobin, respectively. Number of cigarettes smoked per day (CPD) was determined from cigarette butts returned. Puffing parameters were determined through a CreSS® micro device and a 182-item adult smoker questionnaire (ASQ) was administered. The relationship between exposure and demographic factors, smoking machine measured tar yield and CPD was examined in a statistical model (Model A). Topography parameters were added to this model (Model B) which was further expanded (Model C) by adding selected questions from the ASQ identified by a data reduction process. In all the models, CPD was the most important and highest ranking factor determining daily exposure. Other statistically significant factors were number of years smoked, questions related to morning smoking, topography and tar yield categories. In conclusion, the models investigated in this analysis, explain about 30-40% of variability in exposure to nicotine and CO.