Assessment of nicotine dependence symptoms in adolescents: a comparison of five indicators

OBJECTIVE: To examine the psychometric properties, test-retest reliability, and convergent construct validity of five indicators of nicotine dependence (ND) symptoms in adolescents. DESIGN: Analysis of baseline data from a prospective study on the natural history of ND in 1264 adolescents aged 12-13 years. SETTING: Ten Montreal high schools. SUBJECTS: 233 grade 7 students who had smoked cigarettes one or more times in the three months preceding the baseline data collection. MAIN OUTCOME MEASURES: Five indicators of ND symptoms including two that are multi-dimensional (a proxy measure of ICD-10 criteria for tobacco dependence; the Hooked on Nicotine Checklist (HONC)) and three new indicators of "symptom clusters" that emerged from principal component analysis (ND/cravings, withdrawal symptoms, self medication). RESULTS: All five indicators demonstrated acceptable internal and test-retest reliability. The correlation between the HONC and ND/cravings was 0.910. All other correlations between indicators ranged between 0.716-0.824. There was considerable overlap in the independent correlates identified for each indicator. CONCLUSIONS: All five indicators performed well psychometrically. Until the meaning, relative importance, and usefulness of each scale is clarified in longitudinal work, decisions regarding which scale(s) are most informative will depend more on the content of the scales, the need for a multi- or unidimensional indicator, and whether or not the scale is theory based.     

Responsiveness of homocysteine concentrations to food and supplemental folate intakes in smokers and never-smokers enrolled in a diet intervention trial.

We investigated circulating homocysteine concentrations in relation to smoking, folate intake (from food and supplements), serum folate concentrations, and other dietary variables. The present study is part of a parent trial assessing the effects of increasing vegetable, fruit, and fiber intakes and reducing the percentage of energy obtained from fat on breast cancer recurrence in 3,088 women previously diagnosed with breast cancer. Of the 121 smokers enrolled in the parent trial, 85 were available at baseline for the present study and were randomly matched to 85 never-smokers on baseline folate intake, age, and intervention status. Follow-up data were available on 53 smokers (22 intervention and 31 comparison) and 56 never-smokers (24 intervention and 32 comparison). No significant differences in circulating homocysteine and folate concentrations were observed between smokers and never-smokers at baseline. For smokers, significant decreases in circulating homocysteine and significant increases in folate concentrations (p < .05) from baseline to 12 months were observed in the comparison group. For never-smokers, significant decreases in circulating homocysteine and significant increases in folate concentrations were observed in the intervention and comparison groups (p < .05). In the multivariate analysis, changes in serum folate concentration and supplemental folic acid were significantly associated with change in plasma homocysteine concentrations (p < .05). These findings show that increasing supplemental folic acid can reduce homocysteine concentrations, which may have implications for lowering cardiovascular disease risk for smokers and never-smokers.     

Long-term changes in sleep and depressive symptoms of smokers in abstinence.

Few studies have evaluated the impact of smoking cessation on objective measures of sleep. The present study assessed the long-term effects of tobacco smoking abstinence on sleep and depression. A total of 15 chronic smokers with Hamilton Rating Scale for Depression (HAM-D) scores of less than 9 were evaluated. Subjects were screened for baseline data when they were smoking chronically. They underwent a 5-week psychological treatment for tobacco smoking, after which their depressive symptoms and sleep architecture were evaluated at 1, 2, 4, 6, 9, and 12 months of abstinence. We report the results of the seven patients who completed 1 year of evaluations and of those patients who achieved only partial abstinence. Polysomnographic recordings were taken, level of depression was measured with the HAM-D, and urinary cotinine levels also were evaluated. HAM-D scores were analyzed with and without sleep items. Nicotine abstinence reduced latency to rapid eye movement (REM) sleep and increased HAM-D scores, suggesting that chronic smokers have depressive symptoms that may be controlled by nicotine administration.     

Obtaining DNA from a geographically dispersed cohort of current and former smokers: use of mail-based mouthwash collection and monetary incentives.

The feasibility of collecting DNA through the mail from a cohort of current and former smokers was assessed. Also examined was whether monetary incentives would increase response rates. A random sample of 300 subjects, stratified by 20 U.S. communities, was selected to participate. The sampling frame included the 6,726 people who were in both the Community Intervention Trial for Smoking Cessation (COMMIT) between 1988 and 1993 and the follow-up study in 2001, and who consented to being contacted again. Subjects were further randomized within communities to incentive arms of 10 US dollars, 2 US dollars, or 0 US dollars. A total of 110 usable samples were returned (37%), and the 10 US dollars incentive arm had the highest response (43%). Logistic regression revealed no significant predictors of sending a DNA sample, although in a larger study, similar-sized odds ratios would be statistically significant for subjects who received the 10 US dollars incentive and for those who were White, female, or college graduates or whose household incomes were more than 60,000 US dollars per year. The spectrophotometer-determined median DNA yield was 44.93 microg (range=4.00-425.86 microg). Assuming that 50 ng of DNA would be needed for polymerase chain reaction amplification to determine any given genotype, 80-8,517 runs would be attainable. Qualitative findings suggest several methodological improvements to boost response rates. Institutional review board requirements, which are standardized on the inpatient, clinical protocol model, stipulated that noninstitutionally based subjects needed a witness to initial and date every page as well as sign the consent form. This pilot study showed that this requirement could pose some challenges in population-based research.     

A self-administered questionnaire to measure cigarette withdrawal symptoms: the Cigarette Withdrawal Scale.

Because few tobacco withdrawal scales have been submitted to appropriate validity analyses, we sought to develop and assess the validity of a new, self-administered scale measuring cigarette withdrawal symptoms. We generated the instrument content by conducting a qualitative survey of 404 smokers and ex-smokers. Then we tested 61 items on the Internet in 3,050 smokers and ex-smokers. Subsamples provided comprehensive retest data after 17 days (n = 1218) and smoking status after 41 days (n = 673). The study resulted in a 21-item, six-dimension scale labeled the Cigarette Withdrawal Scale (CWS-21). The six subscales cover the main components of nicotine or tobacco withdrawal in the Diagnostic and Statistical Manual of Mental Disorders and International Statistical Classification of Diseases and Related Health Problems and in qualitative data: Depression-anxiety, craving, irritability-impatience, appetite-weight gain, insomnia, and difficulty concentrating. The six scores had a satisfactory test-retest reliability (r = .60-.71) and a high internal consistency (Cronbach's alpha = .83-.96). The factor structure of the scale was robust in a bootstrap resampling procedure. In ex-smokers, all scores except appetite-weight gain and insomnia predicted relapse at 41-day follow-up. In recent ex-smokers who had quit smoking less than 14 days before baseline, all scores except appetite-weight gain decreased between baseline and the 17-day retest. In baseline ex-smokers who relapsed to smoking at the 17-day retest, appetite-weight gain decreased and craving increased between baseline and retest. CWS-21 is a reliable, valid, multidimensional measure of cigarette withdrawal symptoms that is sensitive to change over time and predicts relapse to smoking.     

Initial symptoms of nicotine dependence in adolescents

OBJECTIVES: It has been assumed that nicotine dependence has a slow onset and occurs only after prolonged daily use of tobacco. A cohort of young adolescents was followed to determine when the first symptoms of nicotine dependence occur with respect to the duration and frequency of tobacco use. DESIGN: A cohort of 681 seventh grade students (age 12-13 years) from seven schools in two small cities in central Massachusetts was followed over one year. Detailed information regarding tobacco use was obtained in individual confidential interviews conducted in school three times over the year. The latency time to the onset of symptoms of nicotine dependence was measured from the time a subject first smoked at a frequency of at least once per month. RESULTS: 22% of the 95 subjects who had initiated occasional smoking reported a symptom of nicotine dependence within four weeks of initiating monthly smoking. One or more symptoms were reported by 60 (63%) of these 95 subjects. Of the 60 symptomatic subjects, 62% had reported experiencing their first symptom before smoking daily or began smoking daily only upon experiencing their first symptom. DISCUSSION: The first symptoms of nicotine dependence can appear within days to weeks of the onset of occasional use, often before the onset of daily smoking. The existence of three groups of individuals-rapid onset, slower onset, and resistant-distinguishable from one another by their susceptibility to nicotine dependence, is postulated.     

Differences in risk-taking propensity across inner-city adolescent ever- and never-smokers.

Because adolescent smoking is a significant public health concern, potential value lies in understanding and identifying the psychological factors that distinguish ever- and never-smokers. To that end, we examined the relationship between risk-taking propensity as measured by the Balloon Analogue Risk Task and ever-smoking (i.e., even one puff) versus never-smoking in a sample of 125 predominantly African American high-school adolescents (M = 15.1, SD = 1.5). Results indicated that ever-smokers and never-smokers differed on risk-taking propensity; further risk-taking propensity was related to smoking status above and beyond both demographic variables and a measure of self-reported impulsive sensation seeking. We discuss these results in relation to the potential utility of a multimethod assessment approach (i.e., self-report measures and behavioral tasks) to identify adolescents' risk-taking susceptibilities and engagement in smoking and other risk-taking behaviors.     

Use of the current population survey to characterize subpopulations of continued smokers: a national perspective on the "hardcore" smoker phenomenon.

The existence of "hardcore" smokers, those most likely to have substantial difficulty quitting, may have far reaching impact on how to best allocate cessation resources. It has been suggested that hardcore smokers make up only a small fraction of current smokers and therefore do not represent a significant public health problem. However, little is known about the prevalence and nature of this subgroup of smokers in the United States. Based on a national sample, the 1998-1999 Tobacco Use Supplement to the Current Population Survey, we categorized, based on smoking pattern, groups of current smokers who were over age 25 years (N=33,568). We compared hardcore smokers with other groups of current smokers on demographic, environmental, and smoking variables to assess whether hardcore smokers represent a unique group. Hardcore smokers were defined as established daily smokers, consuming 15 or more cigarettes per day with no reported history of quit attempts. Hardcore smokers represent 13.7% of all current smokers and 17.6% of all established smokers. They are more likely to be male, unmarried, not in the work force, and have lower education. They also are more likely to have started smoking at a younger age, smoke more, and are less likely to report contact with smoking restrictions. This analysis suggests that hardcore smokers are distinct from other groups of smokers. These results also indicate that hardcore smokers account for a substantial proportion of smokers and as such may represent a significant public health challenge that needs to be addressed.     

Nicotine dependence symptoms among adolescents with psychiatric disorders: using a Rasch model to evaluate symptom expression across time.

Little is known about the longitudinal course of symptoms of nicotine dependence among adolescents following interventions designed to affect smoking behavior, particularly among high-risk samples. We used an item-response modeling strategy to examine how well nicotine dependence symptoms cohere to a latent construct, the stability of the construct over time, and the sensitivity of the nicotine dependence symptoms to changes in smoking patterns among adolescents with comorbid psychopathology. Assessments occurred prior to cessation treatment delivered within a randomized clinical trial and again at 6 and 12 months after treatment. We used a Rasch item-response modeling approach to examine nicotine dependence as measured by a structured Adolescent Nicotine Dependence Interview (ANDI) and by the Modified Fagerstr?m Tolerance Questionnaire (mFTQ). These analyses provided support for a unidimensional latent measurement model that can be used to organize symptoms of nicotine dependence obtained from ANDI and mFTQ measures. The derived measure showed good construct validity with significant relationships to smoking levels and salivary cotinine levels. The typical symptom patterns and the relative severity of nicotine dependence symptoms remained stable over multiple assessments. Changes in smoking levels were related longitudinally to changes in nicotine dependence, and changes in nicotine dependence were related to changes in motivation to quit and readiness to change smoking behavior. Several behavioral symptoms were sensitive to change in smoking rate over time, whereas core symptoms of physiological dependence did not evidence significant changes. Results suggest that DSM-IV and mFTQ measures of nicotine dependence provide complementary information when assessing nicotine dependence levels among adolescents with psychiatric disorders.     

Adolescent smokers screened for a nicotine replacement treatment trial: correlates of eligibility and enrollment.

The enrollment process determines the study sample and external validity of clinical trial results; however, few reports describe the process and outcome of screening efforts for smoking cessation studies among adolescents. We describe and evaluate a screening protocol to enroll adolescent smokers for a randomized clinical trial of nicotine replacement therapy. Adolescent smokers obtained the recruitment call-in number (1-800-NO-SMOKE) via media and other advertisements. Trained recruitment staff collected information using an internally developed, targeted telephone screening interview, which was used to determine pre-eligibility for the clinical trial. Correlates of qualification and of study enrollment were determined. Among 1,347 adolescents screened, 329 (24.4%) were eligible to participate in the trial. Light smoking (39.1%) and lack of parental support (14.8%) were the biggest contributors to ineligibility. Eligible adolescents were more likely to be female (66.9% vs. 58.2%, p = .0052) and more likely to be European American (63.5% vs. 52.2%, p = .0003). The higher rates of ineligibility for African Americans and boys were partly explained by lower scores on the Fagerstr?m Test for Nicotine Dependence. Of those eligible to participate in the trial, 159 (48.3%) enrolled. Results underscore the need for screening instruments that are measurement-invariant across ethnicities and gender, and for enrollment strategies that maximize inclusion of eligible participants.     

Value to smokers of improved cessation products: evidence from a willingness-to-pay survey.

The present study demonstrated the use of willingness to pay to value hypothetical new smoking cessation products. Data came from a baseline survey of participants in a clinical trial of medications for smoking cessation (N=356) conducted in New Haven, Connecticut. We analyzed individual willingness to pay for a hypothetical tobacco cessation treatment that is (a) more effective than those currently available and then (b) more effective and attenuates the weight gain often associated with smoking cessation. A majority of the respondents (n=280; 84%) were willing to pay for the more effective treatment, and, of those, 175 (63%) were willing to pay more if the increased effectiveness was accompanied by attenuation of the weight gain associated with smoking cessation. The present study suggests the validity of using willingness-to-pay surveys in assessing the value of new smoking cessation products and products with multifaceted improvements. From these data, we calculated estimates of the value of a quit. For the population studied, this survey suggests a substantial market for more effective smoking cessation treatments.     

Long term and transitional intermittent smokers: a longitudinal study

OBJECTIVE: To investigate differences in snuff consumption, sociodemographic and psychosocial characteristics between baseline intermittent smokers that had become daily smokers, stopped smoking or remained intermittent smokers at the one year follow up. DESIGN/SETTING/PARTICIPANTS/MEASUREMENTS: A population of 12 507 individuals interviewed at baseline in 1992-94 and at a one year follow up, aged 45-69 years, was investigated in a longitudinal study. The three groups of baseline intermittent smokers were compared to the reference population (all others) according to sociodemographic, psychosocial, and snuff consumption characteristics. A multivariate logistic regression model was used to assess differences in psychosocial conditions, adjusting for age, sex, country of origin, marital status, education, and snuff consumption. RESULTS: 60% of all baseline intermittent smokers had remained intermittent smokers, 16% had become daily smokers, and 24% had stopped smoking at the one year follow up. The long term intermittent smokers and those who had stopped smoking were young, unmarried, highly educated, and snuff consumers to a higher extent than the reference population. They also had more psychosocial resources than the reference population, while the psychosocial resources of those who had become daily smokers were poorer. CONCLUSIONS: The majority of intermittent smokers are long term intermittent smokers. The results suggest that long term intermittent smokers have other psychosocial characteristics than daily smokers.     

Abstention from smoking extends life and compresses morbidity: a population based study of health expectancy among smokers and never smokers in Denmark

OBJECTIVE: To estimate health expectancy--that is, the average lifetime in good health--among never smokers, ex-smokers, and smokers in Denmark. DESIGN: A method suggested by Peto and colleagues in 1992 for estimating smoking attributable mortality rates was used to construct a life table for never smokers. This life table and relative risks for death for ex-smokers and smokers versus never smokers were used to estimate life tables for ex-smokers and smokers. Life tables and prevalence rates of health status were combined and health expectancy was calculated by Sullivan's method. SETTING: The Danish adult population. MAIN OUTCOME MEASURES: The expected lifetime in self rated good health or without longstanding illness for never smokers and smokers. RESULTS: The expected lifetime of a 20 year old man who will never begin to smoke is 56.7 years, 48.7 (95% confidence interval (CI), 46.8 to 50.7) years of which are expected to be in self rated good health. The corresponding figures for a man who smokes heavily are 49.5 years, 36.5 (95% CI 35.0 to 38.1 ) years of which are in self rated good health. A 20 year old woman who will never begin to smoke can expect to live a further 60.9 years, with 46.4 (95% CI 44.9 to 47.8) years in self rated good health; if she is a lifelong heavy smoker, her expected lifetime is reduced to 53.8 years, 33.8 (95% CI 31.7 to 35.9) years of which are in self rated good health. Health expectancy based on long standing illness is reduced for smokers when compared with never smokers. CONCLUSIONS: Smoking reduces the expected lifetime in good health and increases the expected lifetime in poor health.