A review of the validity and reliability of smokeless tobacco dependence measures

Introduction

With the growing marketing of alternate tobacco products, advocacy of harm reduction, and smoke free air policies, an overall increase in Smokeless Tobacco (ST) use has been observed since the 1970s. Numerous studies have been published addressing nicotine dependence measures for smokers; however, research in the field of ST dependence measures is scarce.

Purpose

The aim of this study is to summarize the psychometric properties of ST dependence measures by evaluating the reliability and validity of these scales through peer review research.

Methods

A systematic literature search was conducted within the databases of PubMed and OVID Medline. Four publications reporting on the psychometric properties of ST dependence measures were identified; two regarding FTQ based scales, one regarding an FTND based scale, and one comparing two of these modified scales. A predefined set of criteria was used to assess the psychometric properties of these measures.

Results

ST dependence measures depend heavily on two underlying factors, heaviness of tobacco use and withdrawal. The internal consistency of the measures was low to moderate, Cronbach's α ranging from 0.30 to 0.52 Cotinine was used as criterion variable to validate the results of the dependence measures. Concurrent validity against DIS-IV-ND based diagnosis was not established for modified FTQ scale. Predictive validity of these ST dependence scales was measured as abstinence of ST use at three and six months. FTQ-ST was predictive of abstinence at three months however failed to predict six months abstinence.

Conclusion

FTQ and FTND based measures have inherited shortcomings and have limited psychometric properties. With ease of use and wide application in tobacco research, these measures provide preliminary foundation for studying ST dependence. However, the complexity of tobacco dependence requires a multidimensional measure with high validity and reliability for effective prevention care and for research purposes.     

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.     

A multiple motive/multi-dimensional approach to measure smokeless tobacco dependence

Background

Unlike various research studies conducted to address dependence among smokers, only a few studies have examined smokeless tobacco (ST) dependence. The Fagerström Tolerance Questionnaire (FTQ) and Fagerström Test for Nicotine Dependence (FTND) based scales are the most widely used measures of nicotine dependence for both ST users and smokers. These scales were initially developed to measure physical dependence and tolerance and not to assess other salient dimensions of dependence such as craving, compulsion, or withdrawal, as defined by DSM-IV and ICD-10. The aim of this study is to develop and validate a multidimensional scale that has better content coverage, factor structure, and psychometric properties to measure dependence among ST users.

Methods

100 adult male smokeless tobacco users were recruited through email distribution lists and community referral. Participants completed three different nicotine dependence questionnaires and provided information related to their tobacco use and demographic characteristics. They also provided a saliva sample for cotinine measurement. In order to develop the new ST scale, subscales and items were selected based on correlation and factor analysis of the modified WISDM-68. Reliability and validity of the new scale, Oklahoma Scale for Smokeless Tobacco Dependence (OSSTD) were also assessed.

Results

The new ST scale identified seven latent constructs including 23 items to measure ST dependence. Internal consistency as measured by Cronbach's coefficient (α = 0.925) indicated better reliability of OSSTD than FTND-ST. Concurrent validity of OSSTD as evaluated by comparing it with dependence diagnosis and FTND-ST was affirmative. There was a significant correlation between the OSSTD total score and the cotinine levels and tobacco use characteristics among study participants.

Conclusion

OSSTD possesses better psychometric properties and provides an effective and efficient tool to measure ST dependence as a multidimensional construct.     

Evaluating strategies and costs to recruit smokeless tobacco users

We recruited smokeless tobacco users throughout Minnesota to participate in a trial testing telephone counseling versus a written self-help manual for cessation. This paper describes the recruitment strategies applied on a state-wide basis. We established a recruitment tracking system to monitor weekly rates of screened callers and returned consents, allowing us to adjust future recruitment efforts. Screening was completed with 783 callers, with 406 subjects enrolled. Overall 44% of initial contacts and 52% of those screened enrolled in the study. The overall average cost per consented subject was $99. Sports talk radio, small print ads, and newspaper articles based on press releases were consistently effective channels for recruitment. The overall cost was expensive but reflected the geographic diversity of recruitment and the prevalence of oral snuff use.     

A comparison of three smokeless tobacco dependence measures

Smokeless tobacco (ST) use is associated with tobacco dependence and long-term adverse health consequences. Clinical and research tools that can accurately assess ST dependence are needed to improve research and treatment of ST users. Measures of ST dependence have been developed to address this need. We used data from a study evaluating the effectiveness of bupropion sustained release for the treatment of ST use (N = 225) to compare the Fagerström Tolerance Questionnaire for Smokeless Tobacco (FTQ-ST) users, the Severson Smokeless Tobacco Dependency Scale (SSTDS), and the Glover-Nilsson Smokeless Tobacco Behavioral Questionnaire (GN-STBQ). We observed that despite the intention of the scale: (1) all scales were significantly correlated with ST cans consumed per week; (2) the FTQ-ST was significantly correlated with serum nicotine and cotinine concentrations and craving; (3) the GN-STBQ and SSTDS were significantly associated with both craving and withdrawal; and (4) none of the scales were significantly associated with ST abstinence. When all of the scales were entered simultaneously in a multivariable analysis, the SSTDS was the only scale independently associated with withdrawal and craving. As when used with cigarette smokers, the FTQ-ST appeared to measure the construct of physical dependence. The GN-STBQ and SSTDS, designed to measure broader constructs of dependence, were found to predict both withdrawal and craving which may be advantageous in clinical settings. The GN-STBQ and the FTQ-ST did not contribute significantly to the prediction of withdrawal and craving beyond what was accomplished using the SSTDS. The use of the scales is discussed in terms of clinical usefulness and how each scale might assess differing aspects of tobacco dependence.     

The potential impact of a low-nitrosamine smokeless tobacco product on cigarette smoking in the United States: estimates of a panel of experts

OBJECTIVE: To predict the impact on tobacco use in the US of a "harm reduction" policy that requires that the smokeless tobacco product meet low nitrosamine standards, but could be marketed with a warning label consistent with the evidence of relative health risks. METHODS: Low nitrosamine smokeless tobacco (LN-SLT) and cigarette use are predicted by a panel of experts using a modified Delphi approach. We specify a thought experiment to isolate the changes that would occur after the new LN-SLT policy was implemented. RESULTS: The panel predicted that the new policy would accelerate a decrease in smoking prevalence from 1.3 to 3.1 percentage points over 5 years compared to the current SLT product policy, with greater effects on males than females. Introduction of the new product was also predicted to result in modest additional use of SLT overall, with the greatest increases among males who initiated tobacco use under the new policy. CONCLUSION: An overall consensus was reached that the introduction of a new LN-SLT product under strict regulations would increase SLT use, but reduce overall smoking prevalence. This reduction would likely yield substantial health benefits, but uncertainties surround the role of marketing and other tobacco control policies.     

Comparative effectiveness of the nicotine lozenge and tobacco-free snuff for smokeless tobacco reduction

Long-term smokeless tobacco (ST) use is associated with cardiovascular disease and cancer, but not all ST users want to quit. Previous studies have evaluated the effectiveness of nicotine lozenges and tobacco-free snuff for reducing ST use among ST users not ready to quit, but no comparative effectiveness trials of these two products have been conducted. We conducted a multicenter, randomized clinical pilot study evaluating the comparative effectiveness of the 4-mg nicotine lozenge and tobacco-free snuff for reducing ST use and increasing tobacco abstinence among ST users with no intention of quitting in the next 30 days. Participants received 8 weeks of treatment and behavioral counseling on tobacco reduction strategies with follow-up to 26 weeks. We randomized 81 participants (40 nicotine lozenges, 41 tobacco-free snuff). No significant differences in reduction were observed between the two groups at weeks 8, 12, and 26. No significant differences were observed between groups in nicotine withdrawal or tobacco craving. However, both groups significantly reduced (p < .001) ST use in cans/week and dips/day from baseline which was sustained through the end-of-study. The observed biochemically-confirmed abstinence rates at week 26 were similar between groups (12% vs. 12%, one-tailed p = .615). The 4-mg nicotine lozenge and the tobacco-free snuff both appear to be effective and comparable for reducing ST use among ST users not ready to quit in the next 30 days.     

Residential treatment for smokeless tobacco use: a case series

We developed and implemented a novel 8-day residential treatment program for smokeless tobacco (ST) use. A multidisciplinary team delivered behavioral treatment, nicotine patches were adjusted to achieve 100% replacement of baseline peak serum nicotine concentrations, and bupropion sustained-release was prescribed. Mean participant age (± SD) was 47.4 ± 18.2 years. Mean nicotine patch dose at program end was 43.2 mg/day ± 13.9 (range 14 to 66 mg/d). Median percent replacement by serum nicotine concentrations was 86.6% (IQR: 75–113.8%). At 1 year, the biochemically-confirmed (urine anabasine <2.0 ng/mL) self-reported 7-day point prevalence tobacco abstinence rate was 58% (14/24). A residential treatment program for ST users may be effective. More research is needed to replicate our findings and determine if comparable abstinence rates can be achieved with outpatient ST treatment programs using similar behavioral and pharmacotherapies.     

An epidemiologic review of smokeless tobacco health effects and harm reduction potential

A systematic review of the epidemiologic literature on the health effects of smokeless tobacco (ST) and its relevance to the harm reduction model for smoking was undertaken. Published epidemiologic studies, from the US and European countries, meeting defined inclusion criteria and assessing the health effects of smokeless tobacco products were examined. ST use showed evidence of a slightly increased risk for all-cause mortality. Little evidence was found to support a causal relationship between ST use and risk of oral, pancreatic or lung cancer. ST use was not associated with an increased risk of cardiovascular disease or stroke incidence, but evidence suggested ST use was associated with increased mortality from these diseases. Clinical trials evaluating the effectiveness of ST products in smoking cessation have been sparse, and no standardized method for measuring ST dependence has been used, limiting the assessment of their relationship to ST use. Several studies have examined if ST use increases the risk of smoking initiation, but few have modeled this complex behavior appropriately. Overall, epidemiologic studies have not shown strong evidence of elevated tobacco-related disease risks with ST use. More research is necessary to assess the smoking behavioral consequences of ST use prior to its consideration as a harm reduction tool.     

Potential role of autophagy in smokeless tobacco extract-induced cytotoxicity and in morin-induced protection in oral epithelial cells

Toxic components of STE induced serious, adverse human oral health outcomes. In the present study, we observed that STE was involved in oral toxicity by reducing the viability of human squamous epithelial cells, SCC-25, along with the simultaneous induction of both apoptosis and autophagic signaling. STE was also found to induce significant amount ROS generation in SCC-25 cells. The dietary flavonoid morin, found abundantly in a variety of herbs, fruits and wine, has been reported to attenuate ROS-induced pathogenesis including autophagy. In this study we designed three different treatment regimes of morin treatment, such as pre, co, and post – treatment of STE challenged SCC-25 cells. In all cases morin provided cytoprotection to STE challenged SCC-25 cells by augmenting STE induced ROS-dependent cytotoxic autophagy. Hence, morin is a potential option for antioxidant therapy in treatment of STE induced toxicity.     

A pilot study of mailed nicotine lozenges with assisted self-help for the treatment of smokeless tobacco users

Smokeless tobacco (ST) is associated with adverse health consequences yet treatment resources for ST are not widely available. Cost-effective behavioral interventions incorporating self-help materials and counseling calls have been demonstrated to reduce ST use rates and can be easily disseminated, but the feasibility and effectiveness of incorporating pharmacotherapy into this approach have not been evaluated. We conducted a clinical pilot study randomizing 60 patients to 12 weeks of the 4-mg nicotine lozenge or placebo delivered through the mail. All subjects received an assisted self-help intervention (ASH) with telephone support. At the end of the medication phase, lozenges were being used by 63% of subjects in the 4-mg nicotine lozenge group and 43% in placebo. The nicotine lozenge decreased composite withdrawal symptoms and adverse events were minimal. No significant differences were observed in abstinence rates between the two groups at 3 or 6 months. We conclude that the mailing of nicotine lozenges to ST users is a feasible and safe strategy the efficacy of which needs to be evaluated.     

Smokeless tobacco abstinence effects and nicotine gum dose

There were two experiments on abstinence from smokeless tobacco. The purpose of the first experiment was to determine abstinence effects from smokeless tobacco. The purpose of the second experiment was to examine the effects of different doses of nicotine gum on smokeless tobacco abstinence effects. The subjects were male Copenhagen smokeless tobacco users who underwent 3 days of baseline measurement while continuing to use smokeless tobacco ad libitum, and 5 days of the experimental condition. In the first experiment, the subjects were assigned randomly to one of two groups and compared: continuous smokeless tobacco users (n=10), and deprivation plus no nicotine gum (n=10). In the second experiment, subjects were assigned randomly and in a double-blind fashion to one of three groups and compared: (1) deprivation plus 0 mg nicotine gum (n=20); (2) deprivation plus 2 mg nicotine gum (n=20); and (3) deprivation plus 4 mg nicotine gum (n=20). The first experiment showed significant increases upon abstinence for the following variables: (1) craving; (2) difficulty concentrating; (3) restlessness; (4) excessive hunger; (5) eating; (6) reaction time; (7) variability of reaction time and (8) total withdrawal scores for both the self-rated and the observer-rated forms. The second experiment showed that nicotine gum failed to significantly reduce smokeless tobacco abstinence effects, although those with high cotinine levels may receive some benefit from nicotine gum.Sponsored by the National Institute on Drug Abuse Research Grant No. DA05013     

Cigarette,smokeless tobacco,and alcohol use among transgender adults in the United States

BackgroundResearch suggests that sexual minority adults face disparate risks for poor health outcomes. However, prior research on transgender populations has been limited by small and nonprobability samples and has potentially masked important differences between transgender subgroups. We examined disparities in cigarette, smokeless tobacco, and alcohol consumption by transgender and cisgender adults.Methods2014–2017 Behavioral Risk Factor Surveillance System data were used. Multivariable logistic regressions examined differences in cigarette, smokeless tobacco, and alcohol use between cisgender adults and transgender sub-identities: male to female (MTF), female to male (FTM), and gender nonconforming.ResultsCigarette and smokeless tobacco use were higher among transgender adults. The gender nonconforming subgroup reported more binge and heavy drinking. In a multivariable logistic analysis, higher odds of smokeless tobacco use were found for all transgender sub-identities compared to cisgender females. The gender nonconforming group had higher odds of heavy drinking (AOR = 2.09, 95% CI 1.14–3.82) and binge drinking (AOR = 1.94, 95% CI 1.25–3.02) compared to cisgender females. The MTF subcategory was more likely to binge drink (AOR = 1.88, 95% CI 1.44–2.46) compared to cisgender females. The FTM subcategory had lower odds of binge drinking (AOR = 0.49, 95% CI 0.33-0.73) compared to cisgender males.ConclusionsSignificant heterogeneity in smokeless tobacco and alcohol use were found among transgender subgroups, particularly when compared to cisgender females. Our findings demonstrate that it is important to consider sub-identities in both the transgender population and in the reference cisgender population.     

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.     

Bupropion SR for the treatment of smokeless tobacco use

BACKGROUND: No pharmacotherapies have been shown to increase long-term (> or = 6 months) tobacco abstinence rates among smokeless tobacco (ST) users. Bupropion SR has demonstrated potential efficacy for ST users in pilot studies. We conducted a multicenter, randomized, double-blind, placebo-controlled, clinical trial to assess the efficacy and safety of bupropion SR for tobacco abstinence among ST users. METHODS: Adult ST users were randomized to bupropion SR titrated to 150 mg twice daily (N=113) or placebo (N=112) for 12 weeks plus behavioral intervention. The primary endpoint was the 7-day point-prevalence tobacco abstinence rate at week 12. Secondary outcomes included prolonged and continuous tobacco abstinence rates, craving and nicotine withdrawal, and weight gain. RESULTS: The 7-day point-prevalence tobacco abstinence rates did not differ between bupropion SR and placebo at the end treatment (53.1% versus 46.4%; odds ratio (OR) 1.3; p=0.301). The 7-day point-prevalence abstinence did not differ at weeks 24 and 52. The prolonged and continuous tobacco abstinence rates did not differ at weeks 12, 24, and 52. A time-by-treatment interaction was observed in craving over time with greater decreases in the bupropion SR group. At 12 weeks, the mean (+/-S.D.) weight change from baseline among abstinent subjects was an increase of 1.7 (+/-2.9)kg for the bupropion SR group compared to 3.2 (+/-2.7)kg for placebo (p=0.005). CONCLUSIONS: Bupropion SR did not significantly increase tobacco abstinence rates among ST users, but it significantly decreased craving and weight gain over the treatment period.     

Free-base nicotine in tobacco products. Part II. Determination of free-base nicotine in the aqueous extracts of smokeless tobacco products and the relevance of these findings to product design parameters

Reports in the peer-reviewed literature and popular press have alleged that smokeless tobacco product (STP) manufacturers increase the addictiveness of their products by adjusting formulae to increase the relative percentage of nicotine in STP that is not protonated. Such nicotine is more popularly, but incorrectly, known as free-base nicotine (“FBN”) as it is a calculated amount as opposed to a real chemical species in the STP. Some regulators have mandated reporting of FBN as estimated by Henderson–Hasselbalch equation (“HHE”) using the pH-value of an aqueous suspension (or extract) of STP. This is technically incorrect because the HHE is only valid in pure dilute aqueous solution of a single base and its conjugate acid. The aqueous suspensions (or extracts) of STP often contain high concentrations of salts and polymeric anions such as pectate and many other compounds, and there is a molar excess of ammonia over nicotine in some products. These are heretofore-unrecognized sources of error in use of the HHE to estimate relative amount of nicotine that is not protonated results in inaccurate FBN-values. Thus, it is not surprising that attempts to show the relevance of estimated value of FBN in STP to human physiology have failed.     

Effect of tobacco deprivation on the attentional blink in rapid serial visual presentation

When two targets are imbedded in rapid serial visual presentation (RSVP), identification of the second target (T2) is impaired if it occurs within 500 ms of the first target (T1). This attentional blink (AB) is thought to involve interference of resources in processing T1 and T2. The deleterious effect of tobacco deprivation on attention has been documented, but no studies have examined the AB. Nonsmokers (n=30), 12-h tobacco-deprived smokers (n=30), and nondeprived smokers (n=30) were randomly assigned to perform the RSVP with one of three stimulus-duration conditions (96, 113, or 130 ms). Participants completed 48 RSVP trials. Each trial consisted of 16 individually presented words (T1, T2, and 14 distractors), and T2 lagged T1 at serial positions 1-8. Participants verbalized T1 and T2 in order immediately after each trial. Identification of T2 (for correct T1 trials) was impaired at early versus late lag positions, which was especially pronounced in the most difficult (96 ms) condition. There was no evidence for group differences on the AB; however, deprived smokers were worse identifying T1 in the 113-ms condition. These results suggest that the AB is influenced by stimulus duration, but not by 12 h of tobacco deprivation.     

The association of smokeless tobacco use and pack-years of smokeless tobacco with age-related macular degeneration in Indian population

Aim: To explore the association of use versus no use and the influence of pack-year use of smokeless tobacco with that of early and late age-related macular degeneration (AMD) in rural and urban south Indian population. We hypothesized that the use and pack-years of use would be significantly associated with both early and late AMD. We therefore sought to examine subjects who gave a history of using smokeless tobacco and we quantified the usage as pack-years, to examine the association with that of early and late AMD.

Materials and methods: This was part of Sankara Nethralaya: Rural–Urban Age-related Macular degeneration study (SN-RAM study), which was conducted between 2007 and 2010. Subjects aged 60 years or older or those turning 60 in the present calendar year, with a history of using smokeless tobacco were noted along with duration and number of packs used per day. Smokeless tobacco was defined as chewed-tobacco (loose leaves) and/or snuff (finely chopped tobacco). Subjects underwent detailed ophthalmic evaluation including cataract grading using the Lens Opacities Classification System (LOCS III), 45° 4-field stereoscopic fundus photography and AMD evaluation. Pack-years of smokeless tobacco use was stratified as <15, 15–34 and ≥35 years; the association of tobacco use and pack-years of use with that of early and late AMD was examined. A p value of Results: The number of smokeless tobacco users was significantly higher in rural (n?=?767) than in urban groups (n?=?281), p?p?=?0.756 or that between AMD and no AMD, p?=?0.562. Use of smokeless tobacco compared with no use was significantly associated with late AMD, OR=?3.178, 95%CI: 1.095, 9.227, p?=?0.033, when adjusted for age, gender, rural-urban differences, presence of diabetes, socioeconomic status, systolic and diastolic blood pressure, total cholesterol, low-density and high-density lipoprotein levels. The association was not significant for early AMD, p?=?0.582. The pack-years of use did not show a statistically significant association with early or late AMD. Furthermore, out of the 1048 subjects, 547 reported as using areca nut. Of which, 415 (75.8%) subjects had no AMD, 119 (21.7%) showed evidence of early AMD and 13 (2.4%) had late AMD. There was no significant association between the use of areca nut and early AMD, (X² (1, N?=?930)?=?2.345, p?=?0.126) or with that of late AMD (X² (1, N?=?761)?=?0.075, p?=?0.785).

Conclusions: Smokeless tobacco use compared with no use, is associated with late AMD, regardless of the pack-years of use. Tobacco use is a modifiable risk factor. Efforts to reduce or stop the use of smokeless tobacco is indicated in an effort to prevent vision loss with respect to late AMD.