Using MIMIC models to examine the relationship between current smoking and early smoking experiences

Subjective effects as predictors of substance use disorders in a clinical sample: A longitudinal study

BACKGROUND

The literature on the association between subjective effects (SEs; i.e., how an individual perceives their physiological and psychological reactions to a drug) and substance use disorders (SUDs) is largely limited to community samples. The present study addressed the following aims in a clinical sample: whether SEs predict general versus substance-specific SUD in adolescence and adulthood after controlling for conduct disorder symptoms (CDsymp); whether SEs predict SUDs across drug classes; whether SEs predict change in SUD from adolescence to adulthood; and whether there are racial/ethnic differences in associations.

METHODS

Longitudinal analyses were conducted using data from a sample of 744 clinical probands recruited from residential and outpatient SUD treatment facilities in CO during adolescence (Mage = 16.26) and re-assessed twice in adulthood (Mages = 22.56 and 28.96), approximately seven and twelve years after first assessment. SEs and CDsymp were assessed in adolescence. SUD severity was assessed at adolescence and twice during adulthood.

RESULTS

SEs assessed in adolescence robustly predicted general SUD for legal and illegal substances in adolescence and adulthood, whereas CDsymp predicted SUD primarily in adolescence. Higher positive and negative SEs in adolescence were associated with greater SUD severity after controlling for CDsymp, with similar magnitudes. Results indicated cross-substance effects of SEs on SUD. We found no evidence for racial/ethnic differences in associations.

CONCLUSIONS

We investigated the progression of SUD in a high-risk sample with greater odds of sustained SUD. In contrast to CDsymp, both positive and negative SEs consistently predicted general SUD across substances in adolescence and adulthood.

Menthol preference moderates the relationship between cigarette nicotine content choice and reactions in young adults who smoke infrequently

BACKGROUND

Half of young adults who smoke use menthol cigarettes, which is associated with continued smoking and greater nicotine dependence. Additionally, early subjective reactions to cigarettes predict future use. Menthol may blunt the sensory effects of nicotine. We investigated the moderating role of menthol on subjective reactions to, and choice of varied nicotine content cigarettes in young adults who smoke infrequently.

METHODS

In three counterbalanced, double-blinded sessions, young adults who smoke ≤ 15 days/month smoked fixed doses from very low (VLNC), intermediate (INC), and normal (NNC) nicotine content cigarettes, which were menthol or non-menthol depending on preference. Participants chose their preferred cigarette in a final session. Positive and negative subjective reactions were measured in each session. ANOVA tests investigated the relationship between menthol preference, nicotine content, and subjective reactions.

RESULTS

Participants (N = 87) were 18-25 years old and reported smoking 15.2 cigarettes per month over 8 days (35 % menthol). Non-menthol preferring participants had increased negative reactions with greater nicotine content (F(1, 55)= 10.76, p < .001); menthol preferring participants did not. Choice of higher nicotine cigarettes was associated with having reported a greater difference in positive reactions to NNC and VLNC for non-menthol preferring participants (F(1, 55)= 12.72, p < .001) but not for menthol preferring participants.

CONCLUSIONS

Young adults who smoke infrequently are a priority tobacco control population given their high risk of transitioning to daily smoking. Results from this study in the form of subjective reactions indicate that a menthol ban is required for a nicotine reduction standard to be maximally effective in this vulnerable group.

Reactions to reduced nicotine content cigarettes in a sample of young adult, low-frequency smokers

RATIONALE

Reducing nicotine content in cigarettes to ≤ 2.4 mg per g of tobacco [mg/g] reduces smoking behavior and toxicant exposure among adult daily smokers. However, cigarettes with similar nicotine content could support continued experimentation and smoking progression among young adults who smoke infrequently.

OBJECTIVES

This study evaluated the threshold for nicotine in cigarettes that produces reactions associated with smoking progression in a sample of young adults who smoke infrequently.

METHODS

Young adults (n = 87, 18-25 years, 49% female) using tobacco products ≤ 15 days per month completed three counterbalanced, double-blinded sessions, each measuring positive and negative subjective reactions to fixed doses of smoke from investigational cigarettes containing one of three different nicotine contents: normal (NNC; 15.8 mg/g); very low (VLNC; 0.4 mg/g); and intermediate (INC; 2.4 mg/g). In a final session, participants chose one of the cigarettes to self-administer.

RESULTS

Post-cigarette breath carbon monoxide was greater for VLNC than for NNC (p < 0.001). Positive reactions were greater for NNC than INC (p < 0.001) and for INC than VLNC (p = 0.001). Negative reactions were greater for NNC than INC and VLNC (both p < 0.001); INC and VLNC did not differ. Cigarette choices did not differ from an even distribution (43% NNC, 25% INC, 32% VLNC), but choice for NNC or INC was associated with higher ratio of positive to negative reactions during the NNC and INC fixed dose sessions, respectively (p < 0.001).

CONCLUSIONS

Reducing nicotine content will likely lower the abuse liability of cigarettes for most young, low-frequency smokers. Additional work is needed to determine if compensatory smoking may lead to increased toxicant exposure, and if a subset of individuals choosing lower nicotine cigarettes may continue to smoke regardless of nicotine content.

The effect of maternal smoking on offspring smoking is unrelated to heritable personality traits or initial subjective experiences

INTRODUCTION

Maternal smoking is a risk factor for offspring smoking. Lifetime maternal smoking vs. prenatal tobacco exposure (PTE) appear to act through different mechanisms. This study tested the hypothesis that maternal smoking measures' effects on offspring smoking could be attributable to hereditary mechanisms: personality traits (novelty-seeking, impulsivity, neuroticism, self-esteem) and initial subjective smoking experiences (pleasurable, unpleasurable, dizziness).

METHODS

Data were drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns (SECASP) study, an 8-year longitudinal study of 9 th or 10 th graders at baseline (≈age 15) who experiment with smoking (<100 lifetime cigarettes; N=594) at baseline. Young adult smoking frequency at the 8-year follow-up (≈age 23) was examined as a function of baseline characteristics (heritable trait, maternal smoking, PTE, sex) and baseline smoking frequency and nicotine dependence. Structural equation models determined whether inclusion of each heritable trait among offspring confounded the effects of maternal smoking (PTE or maternal smoking) on offspring smoking and nicotine dependence.

RESULTS

Impulsiveness was associated with intermediate adolescent smoking frequency (B=0.135, SD=0.043 p=0.002) and nicotine dependence (B=0.012, SD=0.003, p<0.001). Unpleasurable first experience (B=0.886, SD=0.374, p=0.018) and dizziness (B=0.629, SD=0.293, p=0.032) showed a trend with intermediate smoking frequency that was non-significant after correcting for multiple comparisons. These traits did not confound maternal smoking's effects.

CONCLUSIONS

None of the heritable traits examined in this model explained the effect of maternal smoking measures on adolescence or young adulthood offspring smoking. Further research is needed to elucidate the mechanism by which PTE and maternal smoking are linked to offspring smoking.

Radiation effects on atherosclerosis in atomic bomb survivors: a cross-sectional study using structural equation modeling

Past reports indicated that total-body irradiation at low to moderate doses could be responsible for cardiovascular disease risks, but the mechanism remains unclear. The purpose of this study was to investigate the association between radiation exposure and atherosclerosis, an underlying pathology of cardiovascular diseases, in the Japanese atomic bomb survivors. We performed a cross-sectional study measuring 14 clinical-physiological atherosclerosis indicators during clinical exams from 2010 to 2014 in 3274 participants of the Adult Health Study cohort. Multivariable analyses were performed by using a structural equation model with latent factors representing underlying atherosclerotic pathologies: (1) arterial stiffness, (2) calcification, and (3) plaque　as measured with indicators chosen a priori on the basis of clinical-physiological knowledge. Radiation was linearly associated with calcification (standardized coefficient per Gy 0.15, 95 % confidence interval: CI [0.070, 0.23]) and plaque (0.11, 95 % CI [0.029, 0.20]), small associations that were comparable to about 2 years of aging per Gy of radiation exposure, but not with arterial stiffness (0.036, 95 % CI [− 0.025, 0.095]). The model fitted better and had narrower confidence intervals than separate ordinary regression models explaining individual indicators independently. The associations were less evident when the dose range was restricted to a maximum of 2 or 1 Gy. By combining individual clinical-physiological indicators that are correlated because of common, underlying atherosclerotic pathologies, we found a small, but significant association of radiation with atherosclerosis.

Confirmatory factor analysis comparing incentivized experiments with self-report methods to elicit adolescent smoking and vaping social norms

Many adolescent smoking prevention programmes target social norms, typically evaluated with self-report, susceptible to social desirability bias. An alternative approach with little application in public health are experimental norms elicitation methods. Using the Mechanisms of Networks and Norms Influence on Smoking in Schools (MECHANISMS) study baseline data, from 12–13 year old school pupils (n = 1656) in Northern Ireland and Bogotá (Colombia), we compare two methods of measuring injunctive and descriptive smoking and vaping norms: (1) incentivized experiments, using monetary payments to elicit norms; (2) self-report scales. Confirmatory factor analysis (CFA) examined whether the methods measured the same construct. Paths from exposures (country, sex, personality) to social norms, and associations of norms with (self-reported and objectively measured) smoking behavior/intentions were inspected in another structural model. Second-order CFA showed that latent variables representing experimental and survey norms measurements were measuring the same underlying construct of anti-smoking/vaping norms (Comparative Fit Index = 0.958, Tucker Lewis Index = 0.951, Root Mean Square Error of Approximation = 0.030, Standardized Root Mean Square Residual = 0.034). Adding covariates into a structural model showed significant paths from country to norms (second-order anti-smoking/vaping norms latent variable: standardized factor loading [β] = 0.30, standard error [SE] = 0.09, p < 0.001), and associations of norms with self-reported anti-smoking behavior (β = 0.40, SE = 0.04, p < 0.001), self-reported anti-smoking intentions (β = 0.42, SE = 0.06, p < 0.001), and objectively measured smoking behavior (β = − 0.20, SE = 0.06, p = 0.001). This paper offers evidence for the construct validity of behavioral economic methods of eliciting adolescent smoking and vaping norms. These methods seem to index the same underlying phenomena as commonly-used self-report scales.

National quality evaluation of peri-surgical hearing care for pediatric otitis media with effusion

OBJECTIVE

Otitis media with effusion (OME) is a common disease among children that can lead to grave sequelae with respect to hearing. Thus, when treating OME, appropriate hearing care should be provided; ventilation tube insertion (VTI), a standard approach for treating OME, is no exception. This study examined hearing care for VTI and its associated factors, especially at the national level.

DESIGN

Retrospective database analysis.

SETTING

Taiwan's National Health Insurance Research Database.

PARTICIPANTS

One thousand one hundred and fifty-nine patients who received VTI (age ≤12 years; 2011-12).

INTERVENTION

No intervention.

MAIN OUTCOME MEASURES

Compliance to guidelines: sufficient observation time (OBS), tympanogram before VTI (TYM-B) and hearing tests before and after VTI (HEAR-B and HEAR-A, respectively).

RESULTS

The national proportions of completion for each procedure were 30.1% for OBS, 84.4% for TYM-B, 74.3% for HEAR-B and 36.0% for HEAR-A; those of OBS and HEAR-A were extremely low. Age, nasal allergy and even geographic area were associated with differences across completion patterns. Regression revealed some notable patterns. Compared with non-teaching hospitals, teaching hospitals administered HEAR-B most successfully (odds ratio [OR: 3.20, 95% CI: 1.06-9.63) and the smallest hospital group performed HEAR-B most successfully (OR: 2.92, 95% CI: 1.14-7.46).

CONCLUSION

Several findings surfaced concerning VTI-related hearing care and its association with many clinical and socioeconomic factors in this national study. These findings could serve as a map for improving hearing care quality among children with OME.

Small genome separates native and invasive populations in an ecologically important cosmopolitan grass

The literature suggests that small genomes promote invasion in plants, but little is known about the interaction of genome size with other traits or about the role of genome size during different phases of the invasion process. By intercontinental comparison of native and invasive populations of the common reed Phragmites australis, we revealed a distinct relationship between genome size and invasiveness at the intraspecific level. Monoploid genome size was the only significant variable that clearly separated the North American native plants from those of European origin. The mean Cx value (the amount of DNA in one chromosome set) for source European native populations was 0.490 ± 0.007 (mean ± SD), for North American invasive 0.506 ± 0.020, and for North American native 0.543 ± 0.021. Relative to native populations, the European populations that successfully invaded North America had a smaller genome that was associated with plant traits favoring invasiveness (long rhizomes, early emerging abundant shoots, resistance to aphid attack, and low C:N ratio). The knowledge that invasive populations within species can be identified based on genome size can be applied to screen potentially invasive populations of Phragmites in other parts of the world where they could grow in mixed stands with native plants, as well as to other plant species with intraspecific variation in invasion potential. Moreover, as small genomes are better equipped to respond to extreme environmental conditions such as drought, the mechanism reported here may represent an emerging driver for future invasions and range expansions.

Differences in Subjective Experiences to First Use of Menthol and Nonmenthol Cigarettes in a National Sample of Young Adult Cigarette Smokers

Purpose

Menthol has been hypothesized to ease the harshness of cigarette smoke. Thus, sensory experiences at first cigarette use may be one mechanism by which menthol facilitates progression to regular smoking. This study examined differences in subjective experiences to the first use of a menthol versus nonmenthol cigarette among new young adult smokers.

Methods

Data were drawn from waves 5-8 of the Truth Initiative Young Adult Cohort Study, a national sample of 18-34 year olds assessed every 6 months. Analyses included a subset of young adult current smokers (n = 251) who initiated smoking in the past 6 months. Subjective responses to first cigarette use were assessed across menthol and nonmenthol initiators in bivariate analyses and adjusted models controlling for smoking correlates.

Results

Fifty-two percent of new young adult smokers used a menthol cigarette at first use. First use of a menthol cigarette was higher in those aged 18-24 (vs. 25-34). Most black smokers (93.1%) were menthol initiators compared to 43.9% of white smokers. More than half of menthol and nonmenthol initiates felt relaxed or calm, dizzy, lightheaded, liking the taste and a rush or buzz at first use. Menthol initiators were less likely in bivariate and multivariable analyses to experience feeling nauseated at first use (adjusted odds ratio = 0.45; p = .020) compared to nonmenthol initiators.

Conclusions

While few differences were found between menthol and nonmenthol initiators in their subjective experiences, fewer menthol initiates felt nauseated at first cigarette use. Future research needs to identify additional mechanisms linking menthol initiation to smoking progression.

Implications

Menthol initiators were more likely to be younger (18-24 vs. 25-34), and black (vs. white) compared to nonmenthol initiators. Our finding that menthol initiators were less likely to feel nauseated at first cigarette use compared to nonmenthol initiators suggests that menthol may reduce aversion to early cigarette use among young smokers and thus has the potential to facilitate continued experimentation. Interventions and policy approaches to reduce tobacco use initiation and progression are urgently needed in young people.

Functional multiple indicators, multiple causes measurement error models

Objective measures of oxygen consumption and carbon dioxide production by mammals are used to predict their energy expenditure. Since energy expenditure is not directly observable, it can be viewed as a latent construct with multiple physical indirect measures such as respiratory quotient, volumetric oxygen consumption, and volumetric carbon dioxide production. Metabolic rate is defined as the rate at which metabolism occurs in the body. Metabolic rate is also not directly observable. However, heat is produced as a result of metabolic processes within the body. Therefore, metabolic rate can be approximated by heat production plus some errors. While energy expenditure and metabolic rates are correlated, they are not equivalent. Energy expenditure results from physical function, while metabolism can occur within the body without the occurrence of physical activities. In this manuscript, we present a novel approach for studying the relationship between metabolic rate and indicators of energy expenditure. We do so by extending our previous work on MIMIC ME models to allow responses that are sparsely observed functional data, defining the sparse functional multiple indicators, multiple cause measurement error (FMIMIC ME) models. The mean curves in our proposed methodology are modeled using basis splines. A novel approach for estimating the variance of the classical measurement error based on functional principal components is presented. The model parameters are estimated using the EM algorithm and a discussion of the model's identifiability is provided. We show that the defined model is not a trivial extension of longitudinal or functional data methods, due to the presence of the latent construct. Results from its application to data collected on Zucker diabetic fatty rats are provided. Simulation results investigating the properties of our approach are also presented.

Subjective experiences at first use of cigarette, e-cigarettes, hookah, and cigar products among Texas adolescents

INTRODUCTION

Subjective experiences ("SEs") at first cigarette use have been thoroughly examined; however, limited research has examined SEs at first use of non-cigarette products. This study addresses this gap in the literature.

METHODS

Cross-sectional data from 6th, 8th and 10th grade students in four metropolitan areas of Texas (n=3907/N=461,069). Nausea, coughing, relaxation, rush/buzz, and dizziness at first use were assessed for cigarettes, e-cigarettes, hookah, and cigar products. Chi-square analyses examined differences in the prevalence of first use SEs by product. Weighted multiple logistic regression analyses examined the association of SEs and current product use. Covariates were grade, gender, race/ethnicity, and current other tobacco product use.

RESULTS

Exploratory factor analysis of SEs determined differing factor structures across tobacco products. For example, the following items loaded onto the positive SE factor: 1) relaxation, rush, and dizziness for cigarettes, and 2) relaxation and rush for e-cigarettes, hookah, and cigar products. Prevalence of negative SEs (coughing and nausea) were higher for cigarette and cigar products compared to e-cigarettes and hookah. Positive SEs for cigarettes were associated with increased odds of current cigarette use (AOR=1.51); similarly positive SEs for cigars were associated with increased odds of current cigar use (AOR=2.11). Feeling nauseous at first use of cigars was associated with decreased odds of current cigar use (AOR=0.18). No SEs were associated with current e-cigarette or hookah use.

CONCLUSIONS

Subjective experiences at first use differ by tobacco product. Longitudinal studies are needed to examine temporal relationships between SEs at first use and sustained tobacco use.

Genome-wide time-to-event analysis on smoking progression stages in a family-based study

BACKGROUND

Various pivotal stages in smoking behavior can be identified, including initiation, conversion from experimenting to established use, development of tolerance, and cessation. Previous studies have shown high heritability for age of smoking initiation and cessation; however, time-to-event genome-wide association studies aiming to identify underpinning genes that accelerate or delay these transitions are missing to date.

METHODS

We investigated which single nucleotide polymorphisms (SNPs) across the whole genome contribute to the hazard ratio of transition between different stages of smoking behavior by performing time-to-event analyses within a large Finnish twin family cohort (N = 1962), and further conducted mediation analyses of plausible intermediate traits for significant SNPs.

RESULTS

Genome-wide significant signals were detected for three of the four transitions: (1) for smoking cessation on 10p14 (P = 4.47e-08 for rs72779075 flanked by RP11-575N15 and GATA3), (2) for tolerance on 11p13 (P = 1.29e-08 for rs11031684 in RP1-65P5.1), mediated by smoking quantity, and on 9q34.12 (P = 3.81e-08 for rs2304808 in FUBP3), independent of smoking quantity, and (3) for smoking initiation on 19q13.33 (P = 3.37e-08 for rs73050610 flanked by TRPM4 and SLC6A16) in analysis adjusted for first time sensations. Although our top SNPs did not replicate, another SNP in the TRPM4-SLC6A16 gene region showed statistically significant association after region-based multiple testing correction in an independent Australian twin family sample.

CONCLUSION

Our results suggest that the functional effect of the TRPM4-SLC6A16 gene region deserves further investigation, and that complex neurotransmitter networks including dopamine and glutamate may play a critical role in smoking initiation. Moreover, comparison of these results implies that genetic contributions to the complex smoking behavioral phenotypes vary among the transitions.

Multiple indicators, multiple causes measurement error models

Multiple indicators, multiple causes (MIMIC) models are often employed by researchers studying the effects of an unobservable latent variable on a set of outcomes, when causes of the latent variable are observed. There are times, however, when the causes of the latent variable are not observed because measurements of the causal variable are contaminated by measurement error. The objectives of this paper are as follows: (i) to develop a novel model by extending the classical linear MIMIC model to allow both Berkson and classical measurement errors, defining the MIMIC measurement error (MIMIC ME) model; (ii) to develop likelihood-based estimation methods for the MIMIC ME model; and (iii) to apply the newly defined MIMIC ME model to atomic bomb survivor data to study the impact of dyslipidemia and radiation dose on the physical manifestations of dyslipidemia. As a by-product of our work, we also obtain a data-driven estimate of the variance of the classical measurement error associated with an estimate of the amount of radiation dose received by atomic bomb survivors at the time of their exposure.

A Multiple Indicators Multiple Cause (MIMIC) model of respiratory health and household factors in Chinese children: the seven Northeastern cities (SNEC) study

In China, with the rapid economic development and improvement of living standards over the past few decades, the household living environment has shifted dramatically. The aim of the present study is to assess the impact of home environment factors on respiratory symptoms and asthma in Chinese children. Investigators analyzed data collected in the 25 districts from the seven Northeastern cities to examine health effects on respiratory symptoms and asthma in 31,049 children aged 2-14 years. Factor analysis was used to reduce 33 children's lifestyle and household variables to six new 'factor' variables. The multiple indicators multiple causes approach was used to examine the relationship between indoor air pollution and respiratory health status, controlling for covariates. Factor analyses generated six factor variables of potential household risk factors from an original list of 33 variables. The respiratory symptoms and asthma were significantly associated with the recent home renovation factor (estimate = 0.076, p < 0.001), pet ownership factor (estimate = 0.095, p < 0.001), environmental tobacco smoke (ETS) exposure factor (estimate = 0.181, p < 0.001) and PVC-flooring factor (estimate = 0.031, p = 0.007). Home ventilation factor was not related to any respiratory condition (estimate = 0.028, p = 0.074). Independent respiratory health effects existed for multiple household environmental factors recent home renovation, pet ownership, ETS, and PVC-flooring.

Initial reactions to tobacco and cannabis smoking: a twin study

BACKGROUND AND AIMS

Initial subjective reactions to cannabis and tobacco, broadly classified as positive or negative, have previously been explored for their associations with onset and maintenance of subsequent abuse/dependence. We examine (i) the factorial architecture of self-reported initial reactions to cannabis and tobacco; (ii) whether these factors associate with concurrently reported age at onset of DSM-IV diagnosis of nicotine dependence and cannabis abuse/dependence; and (iii) estimate heritable variation in and covariation between the factors.

DESIGN

Factorial and exploratory structural equation modeling was conducted to examine the factor structure of initial reactions. Cox proportional hazards modeling was employed to examine their association with time to onset of diagnosis of DSM-IV nicotine dependence and cannabis abuse/dependence. Classical twin modeling, using univariate and multivariate models, was used to parse variance in each factor (and the covariance between factors) to their additive genetic, shared environmental and non-shared environmental sources.

SETTING AND PARTICIPANTS

General population sample of Caucasian female twins aged 18-32 years, with a life-time history of tobacco [n = 2393] and cannabis [n = 1445] use.

MEASUREMENT

Self-report of initial subjective reactions to tobacco (cigarettes) and cannabis the first time they were used and time to onset of life-time history of DSM-IV diagnosis of abuse (cannabis) and dependence (cannabis or nicotine).

FINDINGS

Factors representing putatively positive and negative reactions to cannabis and tobacco emerged. Initial reactions to tobacco were associated with onset of DSM-IV diagnosis of nicotine dependence and cannabis abuse/dependence while initial reactions to cannabis were associated with onset of DSM-IV diagnosis of cannabis abuse/dependence alone. Genetic factors played a moderate role in each factor (heritability of 27-35%, P < 0.05), with the remaining variance attributed to individual-specific environment. Covariation across the factors indexing positive and negative initial reactions was attributable to genetic sources (0.18-0.58, P < 0.05) and to overlapping individual-specific environmental factors (-0.16 to 0.36, P < 0.05).

CONCLUSIONS

Initial subjective reactions to tobacco are associated with onset of DSM-IV diagnosis of nicotine dependence and cannabis abuse/dependence while initial subjective reactions to cannabis are only associated with onset of diagnosis of DSM-IV cannabis abuse/dependence. Genetic and environmental factors underpin the overlap across the factors representing initial reactions, both positive and negative.

Factor structure of early smoking experiences and associations with smoking behavior: valence or sensitivity model?

The Early Smoking Experience (ESE) questionnaire is the most widely used questionnaire to assess initial subjective experiences of cigarette smoking. However, its factor structure is not clearly defined and can be perceived from two main standpoints: valence, or positive and negative experiences, and sensitivity to nicotine. This article explores the ESE's factor structure and determines which standpoint was more relevant. It compares two groups of young Swiss men (German- and French-speaking). We examined baseline data on 3,368 tobacco users from a representative sample in the ongoing Cohort Study on Substance Use Risk Factors (C-SURF). ESE, continued tobacco use, weekly smoking and nicotine dependence were assessed. Exploratory structural equation modeling (ESEM) and structural equation modeling (SEM) were performed. ESEM clearly distinguished positive experiences from negative experiences, but negative experiences were divided in experiences related to dizziness and experiences related to irritations. SEM underlined the reinforcing effects of positive experiences, but also of experiences related to dizziness on nicotine dependence and weekly smoking. The best ESE structure for predictive accuracy of experiences on smoking behavior was a compromise between the valence and sensitivity standpoints, which showed clinical relevance.

Early smoking onset may promise initial pleasurable sensations and later addiction

There is converging evidence suggesting a particular susceptibility to the addictive properties of nicotine among adolescents. The aim of the current study was to prospectively ascertain the relationship between age at first cigarette and initial smoking experiences, and to examine the combined effects of these characteristics of adolescent smoking behavior on adult smoking. It was hypothesized that the association between earlier age at first cigarette and later development of nicotine dependence may, at least in part, be attributable to differences in experiencing pleasurable early smoking sensations. Data were drawn from the participants of the Mannheim Study of Children at Risk, an ongoing epidemiological cohort study from birth to adulthood. Structured interviews at age 15, 19 and 22 years were conducted to assess the age at first cigarette, early smoking experiences and current smoking behavior in 213 young adults. In addition, the participants completed the Fagerström Test for Nicotine Dependence. Adolescents who smoked their first cigarette at an earlier age reported more pleasurable sensations from the cigarette, and they were more likely to be regular smokers at age 22. The age at first cigarette also predicted the number of cigarettes smoked and dependence at age 22. Thus, both the age of first cigarette and the pleasure experienced from the cigarette independently predicted aspects of smoking at age 22.

Initial Smoking Experiences and Current Smoking Behaviors and Perceptions among Current Smokers

Purpose. We examine early-onset cigarette smoking and how, if at all, it is related to subsequent smoking practices. Methods. From 2004 to 2007, face-to-face interviews were conducted with 485 adult cigarette smokers residing in the Atlanta metropolitan area. Data analysis involved a multivariate analysis to determine whether age of smoking onset was related to current smoking practices when the effects of gender, age, race, marital/relationship status, income, and educational attainment were taken into account. Results. The mean age for smoking onset was 14.8, and more than one-half of all smokers had their first cigarette between the ages of 12 and 16. Most people reported an interval of less than one month between their first and second time using tobacco. Earlier onset cigarette smoking was related to more cigarette use and worse tobacco-related health outcomes in adulthood. Conclusions. Early prevention and intervention are needed to avoid early-onset smoking behaviors. Intervening after initial experimentation but before patterned smoking practices are established will be challenging, as the interval between initial and subsequent use tends to be short.

The relationship between subjective experiences during first use of tobacco and cannabis and the effect of the substance experienced first

INTRODUCTION

We examined the positive and negative subjective feelings associated with initial tobacco and cannabis use as well as the role of these experiences in regular use. Additionally, we investigated the effect of the first substance experienced on initial subjective experiences and later regular use.

METHODS

Baseline data from a representative sample of young Swiss men were obtained from an ongoing Cohort Study on Substance Use Risk Factors, which includes 2,321 lifetime tobacco and cannabis users. We assessed the age of first tobacco and cannabis use along with the subjective experiences associated with initial use. Additionally, subjective experiences related to regular use of both substances were analyzed.

RESULTS

The initial subjective experiences were divided into positive and negative for each substance, and we found that the feelings associated with first use of tobacco and cannabis were similar. Moreover, the participants who used cannabis before tobacco reported fewer negative experiences associated with first tobacco use, whereas the participants who initially used tobacco reported more negative experiences related to first cannabis use. Also, we identified that regular use was encouraged by positive experiences and that negative experiences were more adverse for regular use of cannabis compared with tobacco.

CONCLUSIONS

Taken together, these results indicate that similar subjective experiences were associated with the first use of tobacco and cannabis. Also, the use of cannabis before tobacco, which occurred in only a minority of users, had the potential to enhance the effects of initial tobacco use.

Modeling psychological well-being and family relationships among retired older people in Taiwan

Well-being is an important indicator of an individual's quality of life, especially for retired people. In the present study, we investigated the psychological well-being (PWB) of retired Taipei (Taiwan) older people and its associations with sex, family relationships, and health status. A structured questionnaire was used to measure demographics, family relationships, and perceived health status, as well as Ryff's PWB Scales. Data were analyzed from 268 retired olderpeople recruited from social service centres and public parks from September to November 2010. The Multiple Indicators Multiple Causes model demonstrated a very good fit of Ryff's PWB Scales and their relations to sex, family relationships, and perceived health status. The link with PWB was stronger for family relationships than for perceived health. The Mandarin translation of Ryff's PWB Scales was found to be suitable and easy to administer to Taiwanese olderpeople. The findings suggest that nurses should note that improving family relations will facilitate the PWB of retired olderpeople, which results in better outcomes of care.

Initial reactions to tobacco use and risk of future regular use

INTRODUCTION

Studies suggest that initial smoking pleasure influences future smoking behavior. We investigated how initial reactions to cigarettes or Swedish smokeless tobacco (snus) were associated with future use among 10,708 adults from the Swedish Twin Registry.

METHODS

The Early Smoking Experience questionnaire captured physiologic reactions to initial tobacco use. Binary recursive partitioning (BRP) identified combinations of initial reactions predictive of regular tobacco use. Analyses, stratified by sex, were conducted separately among those who experimented with only cigarettes (EC), only snus (ES), and both products (EC+S).

RESULTS

Among EC, 39.8% of men and 43.7% of women became smokers, while among ES, 78.6% of men and 53.7% of women became snus users. Among EC+S, 31.3% of men and 20.0% of women became dual users. BRP identified different reactions as predictive of future smoking for men (buzz) and women (dizziness, difficulty inhaling). No initial reaction predicted future snus use among men, but pleasant sensations, later age at first use, and relaxation predicted future snus use for women. Among EC+S, future exclusive use of either product was associated with a favorable initial reaction to that product. Dual users experienced higher prevalence of pleasant reactions and lower prevalence of unpleasant reactions in response to both products.

CONCLUSIONS

Our findings support that those who progress to regular tobacco use may be sensitive to the rewarding effects of nicotine but suggest that initial reactions differ by tobacco type. A high proportion of men became regular snus users regardless of initial reactions.

Subjective effects for alcohol, tobacco, and marijuana association with cross-drug outcomes

METHODS

The cross-drug relationship of subjective experiences between alcohol, tobacco, and marijuana and problem drug use behaviors were examined. Data were drawn from 3853 individuals between the ages of 11 and 30 years of age participating in the Colorado Center on Antisocial Drug Dependence [CADD]. Subjective experiences were assessed using a 13-item questionnaire that included positive and negative responses for alcohol, tobacco, and marijuana. Lifetime abuse and dependence on these three drugs was assessed using the Composite International Diagnostic Interview, Substance Abuse Module [CIDI-SAM].

RESULTS

Positive and negative subjective experience scales were similar for alcohol, tobacco, and marijuana, although the hierarchical ordering of items differed by drug. Subjective experience scales for each of the three drugs examined correlated significantly, with the strongest relationship being for alcohol and marijuana experiences. Significant associations were identified between how a person experienced a drug and abuse and dependence status for the same or different drug.

CONCLUSION

Cross-drug relationships provide evidence for a common liability or sensitivity towards responding in a similar manner to drugs of abuse within and across different pharmacological classes.

Do early smoking experiences count in development of smoking?: temporal stability and predictive validity of an early smoking experience questionnaire in adolescents

AIMS

The experience during initial experimentation with smoking might influence later development of smoking behavior; however, measuring early smoking experience (ESE) usually requires self-reports for which stability and predictive validity are relatively understudied. The aims of the study are (a) to examine temporal stability of the ESE questionnaire and (b) to test the hypothesis that early pleasant and unpleasant experience scales predict changes in smoking status among adolescents.

METHODS

In two waves of the Budapest Adolescent Smoking study, a school-based longitudinal study, 1,286 ninth-grade students reported their ESE on both occasions (45.9% girls; mean age = 15.3, SD = 0.54). Questions related to smoking behavior and ESEs were administered in both waves (average 5 month apart). To examine temporal stability, test-retest correlations and a multiindicator autoregressive model were estimated. To test the predictive validity, 2 structural equation models with binary outcome variables (change in smoking status) were estimated in experimenters (N = 798) and nondaily smokers (N = 506) separately.

RESULTS

Test-retest correlations of pleasant and unpleasant experiences were .63 and .66, respectively. Pleasant and unpleasant experiences predict the change of smoking status in the group of experimenters (odds ratio [OR] = 1.57 [1.00-2.48] and 0.58 [0.42-0.80], respectively), but these coefficients (OR = 1.53 [0.79-1.74] and 1.17 [0.82-2.83], respectively) did not reach the level of significance in nondaily smokers.

CONCLUSIONS

Self-reports of ESE demonstrate good short-term temporal stability. The early unpleasant smoking experience might have a different role in different stages of smoking acquisition.

Alcohol expectancy increases positive responses to cigarettes in young, escalating smokers

RATIONALE

A large proportion of smokers consolidate their smoking patterns during young adulthood, and it is possible that the high rates of drinking found in this age group may facilitate the transition from nondaily to daily cigarette use.

OBJECTIVE

The primary aim of this study was to examine how alcohol alters the subjective effects of smoking in heavy-drinking young adults (age 21-25) who are still at an experimental stage of smoking but show recent increases in their smoking behavior.

METHODS

Using a within-subject design, we examined whether alcohol or the expectation of receiving alcohol increased either subjective responses to smoking or the amount smoked. Subjects participated in three sessions, in which they received alcohol (0.08 g/dL targeted blood alcohol level), a taste-masked placebo presented as alcohol, or a mixer beverage not presented as alcohol. Measures included positive and negative subjective reactivity (e.g., satisfaction, nausea, craving relief, and enjoyment of airway sensations) associated with smoking a single cigarette and subsequent ad lib smoking behavior.

RESULTS

Both conditions in which the subjects expected to receive alcohol increased positive effects of smoking (satisfaction, calm, and taste), compared to the mixer beverage. Alcohol, compared to the placebo and mixer beverages, decreased negative effects (nausea) associated with smoking a cigarette and increased subsequent smoking.

CONCLUSIONS

This initial study has implications for understanding how alcohol and the expectation of alcohol improves the experience of smoking in nondaily smokers who are still at an experimental stage of smoking.

Early smoking experience in adolescents

Initial smoking experience is a potential predictor of later smoking. Our study has a twofold aim: (1) to provide further support for construct validity of retrospective measurement of an early smoking experience questionnaire (ESE) in a representative sample of adolescents; and (2) to examine the association of initial smoking experience with sensation-seeking, current smoking and nicotine dependence. Participants were ninth-grade high-school students who had tried smoking, even if only a puff. Data from 1599 students (62% of the total sample) were analyzed, including tobacco use history, symptoms of early smoking experience (ESE), and sensation-seeking. Both exploratory and confirmatory factor analysis supported the two-factorial structure of ESE including pleasant and unpleasant experiences. A CFA analysis with covariates revealed that sensation-seeking, age and gender are significantly associated with pleasant experience, whereas gender is associated significantly only with unpleasant experience. A multinomial regression analysis revealed that pleasant experience positively and unpleasant experience negatively predicts intermittent and regular smoking compared with experimenters. Both pleasant and unpleasant experiences predict the nicotine dependence among intermittent and daily smokers. Our study supports the construct validity of the early smoking experience questionnaire in a large sample of adolescents.