Revealing the multidimensional framework of the Minnesota nicotine withdrawal scale.
ABSTRACT The version of the Minnesota Nicotine Withdrawal Scale (MNWS) under consideration consists of nine items. No psychometric analyses of this version have been published. The objectives of this investigation were to perform a factor analysis and to further assess the psychometric properties of the MNWS.
Data came from three Phase II clinical trials on varenicline, developed for smoking cessation, in a sample of smokers. Exploratory factor analysis was used to examine the structure of the MNWS in the first completed study (n = 626) over various time periods. The postulated factor structure was then tested in a set of confirmatory analyses conducted on two subsequent studies (n = 627, n = 312). The proposed structure was further evaluated through construct validity and reliability analyses.
The nine items of the MNWS included the following: urge to smoke (craving); depressed mood; irritability, frustration, or anger; anxiety; difficulty concentrating; restlessness; increased appetite; difficulty going to sleep; and difficulty staying asleep. Each item was rated by a subject on an ordinal scale from 0 (not at all) to 4 (extreme).
Scree plots and rotated factor patterns from the exploratory factor analyses revealed two multi-item domains--Negative Affect with four items and Insomnia with two items--and three individual items (Craving, Restlessness, Increased Appetite). Confirmatory factor analyses supported the structure with fit indexes exceeding 0.90. The multidimensional framework of the MNWS correlated as expected with health status, depicted an expected course of withdrawal symptoms over time, predicted the sensitivity of withdrawal symptoms on subsequent cessation, and produced internal reliability estimates above 0.70.
Evidence is obtained to support the validity and reliability of the multidimensional structure of the nine-item MNWS. The data suggest that the MNWS has individual constructs on Negative Affect (depressed mood; irritability, frustration, or anger; anxiety; difficulty concentrating), Insomnia (difficulty going to sleep; difficulty staying asleep), Craving, Restlessness, and Increased Appetite. As such, analyzing each construct separately would strengthen the analysis of the popular MNWS.
[Show abstract] [Hide abstract]
ABSTRACT: Introduction: Improved smoking cessation rates are urgently required if New Zealand is to reach its target of a smokefree nation by 2025, during which some 600,000 smokers will need to quit. Nicotine replacement therapy remains a core part of the pharmacological approach to smoking cessation. Oral nicotine solutions with rapid onset have recently become available. We have examined the effect of a nicotine spray and a nicotine patch on smoking cessation for 12 months. Methods: We enrolled potential participants-smokers wanting to quit aged 18-70 years, who smoked >= 9 cigarettes per day-with Fagerstrom Test of Nicotine Dependence score >= 3 in a double-blind trial in 3 trial sites. Smokers were randomized to a nicotine or placebo spray for 6 months, and all received nicotine patches daily for 5 months. They were followed at regular intervals for 12 months. Results: A total of 1,423 subjects were randomized to nicotine oral spray (1 mg of nicotine free base per spray) plus nicotine patch or a placebo spray and nicotine patch. The nicotine mouth spray plus nicotine patch showed significant improvements in prolonged abstinence for all measures to 6 months (7 consecutive days at each visit for 6 months: 15.5% vs. 10.6%; p = .006) for the combination versus placebo and nicotine patch. Thereafter, the differences were not significant. Conclusions: The addition of a nicotine mouth spray to a nicotine replacement patch in a population of smokers receiving a low level of behavioral support improved early quitting, but the effects were not sustained.Nicotine & Tobacco Research 05/2014; 16(10). DOI:10.1093/ntr/ntu084 · 2.81 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Background and AimsNicotine vaccination has been proposed as a possible treatment to aid smoking cessation. First efficacy results of the nicotine vaccine 3′-AmNic-rEPA (NicVAX) showed that only a subgroup of the top 30% antibody responders achieved higher abstinence rates than placebo. The present study examined the efficacy of adding NicVAX versus placebo to varenicline and behavioural support as an aid in smoking cessation and relapse prevention.DesignRandomized placebo-controlled trial.SettingTwo research centres (Maastricht University Medical Centre and Slotervaart Hospital) in the Netherlands.ParticipantsA total of 558 smokers were assigned randomly to six injections with NicVAX (n = 278) or placebo (n = 280) both co-administered with open label varenicline and behavioural support.MeasuresOutcomes were prolonged carbon monoxide-validated abstinence from weeks 9 to 52 (primary) and weeks 37 to 52 (secondary). We also performed a pre-planned subgroup analysis in the top 30% antibody responders.FindingsThere was no difference in abstinence rates between NicVAX and placebo from weeks 9 to 52 [27.7 versus 30.0%, odds ratio (OR) = 0.89, 95% confidence interval (CI) = 0.62–1.29] or weeks 37 to 52 (33.8 versus 33.2%, OR = 1.03, 95% CI = 0.73–1.46). The top 30% antibody responders, compared to the placebo group, showed a non-significant tendency towards higher abstinence rates from weeks 37 to 52 (42.2 versus 33.2%, OR = 1.47, 95% CI = 0.89–2.42).Conclusion The nicotine vaccine, NicVAX, does not appear to improve the chances of stopping smoking when given in addition to varenicline and behavioural support.Addiction 06/2014; 109(8). DOI:10.1111/add.12573 · 4.60 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Background Waterpipe use has increased dramatically in the Middle East and other parts of the world. Many users exhibit signs of dependence, including withdrawal and difficulty quitting, but there is no evidence base to guide cessation efforts. Methods We developed a behavioral cessation program for willing-to-quit waterpipe users, and evaluated its feasibility and efficacy in a pilot, two arm, parallel group, randomized, open label trial in Aleppo, Syria. Fifty adults who smoked waterpipe ≥ 3 times per week in the last year, did not smoke cigarettes, and were interested in quitting were randomized to receive either brief (1 in-person session and 3 phone calls) or Intensive (3 in-person sessions and 5 phone calls) behavioral cessation treatment delivered by a trained physician in a clinic setting. The primary efficacy end point of the developed interventions was prolonged abstinence at three months post quit day, assessed by self-report and exhaled carbon monoxide levels of < 10 ppm. Secondary end points were 7 day point-prevalent abstinence and adherence to treatment. Results Thirty percent of participants were fully adherent to treatment, which did not vary by treatment group. The proportions of participants in the brief and intensive interventions with prolonged abstinence at 3-month assessment were 30.4% and 44.4%, respectively. Previous success in quitting (OR = 3.57; 95% CI = 1.03-12.43) predicted cessation. Higher baseline readiness to quit, more confidence in quitting, and being unemployed predicted better adherence to treatment (all p-values < 0.05). Conclusions Brief behavioral cessation treatment for waterpipe users appears to be feasible and effective.Addictive behaviors 06/2014; DOI:10.1016/j.addbeh.2014.02.012 · 2.44 Impact Factor