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Abstract: Aims: To conduct a systematic review and meta‐analysis of studies in order to estimate the effect of US medical marijuana laws (MMLs) on past‐month marijuana use prevalence among adolescents. Methods: A total of 2999 papers from 17 literature sources were screened systematically. Eleven studies, developed from four ongoing large national surveys, were meta‐analyzed. Estimates of MML effects on any past‐month marijuana use prevalence from included studies were obtained from comparisons of pre–post MML changes in MML states to changes in non‐MML states over comparable time‐periods. These estimates were standardized and entered into a meta‐analysis model with fixed‐effects for each study. Heterogeneity among the study estimates by national data survey was tested with an omnibus F‐test. Estimates of effects on additional marijuana outcomes, of MML provisions (e.g. dispensaries) and among demographic subgroups were abstracted and summarized. Key methodological and modeling characteristics were also described. Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were followed. Results: None of the 11 studies found significant estimates of pre–post MML changes compared with contemporaneous changes in non‐MML states for marijuana use prevalence among adolescents. The meta‐analysis yielded a non‐significant pooled estimate (standardized mean difference) of −0.003 (95% confidence interval = −0.012, +0.007). Four studies compared MML with non‐MML states on pre‐MML differences and all found higher rates of past‐month marijuana use in MML states pre‐MML passage. Additional tests of specific MML provisions, of MML effects on additional marijuana outcomes and among subgroups generally yielded non‐significant results, although limited heterogeneity may warrant further study. Conclusions: Synthesis of the current evidence does not support the hypothesis that US medical marijuana laws (MMLs) until 2014 have led to increases in adolescent marijuana use prevalence. Limited heterogeneity exists among estimates of effects of MMLs on other patterns of marijuana use, of effects within particular population subgroups and of effects of specific MML provisions. [ABSTRACT FROM AUTHOR]

Aims: This paper presents updated prevalence estimates of awareness, ever‐use, and current use of nicotine vaping products (NVPs) from 14 International Tobacco Control Policy Evaluation Project (ITC Project) countries that have varying regulations governing NVP sales and marketing. Design, Setting, Participants and Measurements: A cross‐sectional analysis of adult (≥ 18 years) current smokers and ex‐smokers from 14 countries participating in the ITC Project. Data from the most recent survey questionnaire for each country were included, which spanned the period 2013–17. Countries were categorized into four groups based on regulations governing NVP sales and marketing (allowable or not), and level of enforcement (strict or weak where NVPs are not permitted to be sold): (1) most restrictive policies (MRPs), not legal to be sold or marketed with strict enforcement: Australia, Brazil, Uruguay; (2) restrictive policies (RPs), not approved for sale or marketing with weak enforcement: Canada, Malaysia, Mexico, New Zealand; (3) less restrictive policies (LRPs), legal to be sold and marketed with regulations: England, the Netherlands, Republic of Korea, United States; and (4) no regulatory policies (NRPs), Bangladesh, China, Zambia. Countries were also grouped by World Bank Income Classifications. Country‐specific weighted logistic regression models estimated adjusted NVP prevalence estimates for: awareness, ever/current use, and frequency of use (daily versus non‐daily). Findings NVP awareness and use were lowest in NRP countries. Generally, ever‐ and current use of NVPs were lower in MRP countries (ever‐use = 7.1–48.9%; current use = 0.3–3.5%) relative to LRP countries (ever‐use = 38.9–66.6%; current use = 5.5–17.2%) and RP countries (ever‐use = 10.0–62.4%; current use = 1.4–15.5%). NVP use was highest among high‐income countries, followed by upper–middle‐income countries, and then by lower–middle‐income countries. Conclusions: With a few exceptions, awareness and use of nicotine vaping products varied by the strength of national regulations governing nicotine vaping product sales/marketing, and by country income. In countries with no regulatory policies, use rates were very low, suggesting that there was little availability, marketing and/or interest in nicotine vaping products in these countries where smoking populations are predominantly poorer. The higher awareness and use of nicotine vaping products in high income countries with moderately (e.g. Canada, New Zealand) and less (e.g. England, United States) restrictive policies, is likely due to the greater availability and affordability of nicotine vaping products. [ABSTRACT FROM AUTHOR]

This paper models the predicted impact of tobacco price increases proposed in the United States and Australia during 2009 on smoking prevalence in 2010 while taking account of the effects of financial stress among smokers on cessation rates. Two models of smoking prevalence were developed for each country. In model 1, prevalence rates were determined by price elasticity estimates. In model 2 price elasticity was moderated by financial stress. Each model was used to estimate smoking prevalence in 2010 in Australia and the United States. Proposed price increases resulted in a 1.89% and 7.84% decrease in smoking participation among low socio-economic status (SES) groups in the United States and Australia, respectively. Model 1 overestimated the number of individuals expected to quit in both the United States (0.13% of smokers) and Australia (0.36% of smokers) by failing to take account of the differential effects of the tax on financially stressed smokers. The proportion of low-income smokers under financial stress increased in both countries in 2010 (by 1.06% in the United States and 3.75% in Australia). The inclusion of financial stress when modelling the impact of price on smoking prevalence suggests that the population health returns of increased cigarette price will diminish over time. As it is likely that the proportion of low-income smokers under financial stress will also increase in 2010, future population-based approaches to reducing smoking will need to address this factor. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the effectiveness of a combined internet and text message intervention for smoking cessation compared with an internet intervention alone. The text message intervention was optimized for engagement in an earlier multiphase optimization (MOST) screening phase. Design A parallel, two‐group, individually randomized clinical trial (RCT) was conducted in a MOST confirming phase. Recruitment spanned December 2018 to March 2019. Follow‐up was conducted at 3 and 9 months, beginning March 2019 and ending January 2020. Setting: United States: a digital study conducted among new registrants on a free tobacco cessation website. Participants: Eligible individuals were 618 adult current smokers in the United States, age 18 years or older who signed up for text messages during website registration (67.2% female, 70.4% white). Interventions: The treatment arm (WEB+TXT; n = 311) received access to the website and text messaging. The control arm (WEB; n = 307) received access to the website alone. Measurements The primary outcome was self‐reported 30‐day point prevalence abstinence (ppa) at 9 months post‐randomization analyzed under intent to treat (ITT), counting non‐responders as smoking. Secondary outcomes included 3‐month measures of 30‐day ppa, intervention engagement and intervention satisfaction. Findings Abstinence rates at 9 months were 23.1% among WEB+TXT and 23.2% among WEB (OR = 1.00, 95% CI = 0.69–1.45; P = 0.99). WEB+TXT increased engagement with 5 of 6 interactive features (standardized mean difference (SMD) = 0.26–0.47, all P < 0.001) and repeat website visits (48.7% vs 38.9%, SMD = 0.14, P = 0.02). Satisfaction metrics favored WEB+TXT (satisfied: 96.3% vs 90.5%, SMD = 0.17, P = 0.008; recommend to friend: 95.9% vs 90.1%, SMD = 0.16, P = 0.028). Conclusions: A randomized controlled trial found no evidence that a combined internet and text message intervention for smoking cessation compared with an internet intervention alone increased 9‐month abstinence rates among adult current smokers in the United States, despite evidence of higher levels of intervention engagement and satisfaction at 3 months. [ABSTRACT FROM AUTHOR]

Background and Aim: There have been substantial recent changes in youth tobacco product use in the United States—including, notably, a rapid increase in use of e‐cigarettes. It is not known whether, and if so how far, these changes are reflected in levels of nicotine dependence. This study used data from a large, nationally representative sample of US adolescents to (i) estimate the annual prevalence of nicotine dependence in relation to current use of tobacco products, (ii) describe trends in dependence over time and (iii) evaluate whether the increase in youth use of tobacco products has been paralleled by a similar increase in the population burden of nicotine dependence. Design Secondary analysis of National Youth Tobacco Surveys conducted annually, 2012–19. Setting: United States. Participants: A total of 86 902 high school students. Measurements Prevalence of (i) strong cravings to use tobacco in the past 30 days and (ii) wanting to use nicotine products within 30 minutes of waking, in relation to type of product used (cigarettes, other combustible tobacco, smokeless tobacco, e‐cigarettes). Findings Between 2012 and 2019 there was a marked decline in past 30‐day cigarette smoking and a surge in use of e‐cigarettes. Different products were associated with differing levels of nicotine dependence, with cigarettes characterized by highest dependence (strong craving 42.3%; wanting to use within 30 minutes 16.8% among exclusive users in 2019) and e‐cigarettes in otherwise tobacco‐naive students by low dependence (16.1 and 8.8% respectively in 2019). The overall 33.8% increase in population use of nicotine products between 2012 and 2019 (from 23.2 to 31.2%) was not accompanied by an equivalent increase in overall population burden of dependence {percentage reporting craving 10.9% [95% confidence interval (CI) = 9.8–12.2%] in 2012 and 9.5% (95% CI = 7.5–12.0%) in 2019; wanting to use within 30 minutes 4.7% (95% CI = 4.0–5.5%) in 2012, 5.4% (95% CI = 4.0–7.2%) in 2019}. Conclusions: Among US high school students, increases in the prevalence of nicotine product use from 2012 to 2019 do not appear to have been accompanied by a similar increase in the population burden of nicotine dependence. This may be at least partly attributable to a shift in the most common product of choice from cigarettes (on which users are most dependent) to e‐cigarettes (on which users are least dependent). [ABSTRACT FROM AUTHOR]

Background and Aims: Debate exists about whether health professionals (HPs) should advise smokers to use nicotine vaping products (NVPs) to quit smoking. The objectives were to examine in four countries: (1) the prevalence of HP discussions and recommendations to use an NVP; (2) who initiated NVP discussions; (3) the type of HP advice received about NVPs; and (4) smoker's characteristics related to receiving advice about NVPs. Design Cross‐sectional study using multivariable logistic regression analyses on weighted data from the 2016 ITC Four Country Smoking and Vaping Survey (ITC 4CV1). Setting: Four countries with varying regulations governing the sale and marketing of NVPs: 'most restrictive' (Australia), 'restrictive' (Canada) or 'less restrictive' (England and United States). Participants: A total of 6615 adult smokers who reported having visited an HP in the last year (drawn from the total sample of 12 294 4CV1 respondents, of whom 9398 reported smoking cigarettes daily or weekly). Respondents were from the United States (n = 1518), England (n = 2116), Australia (n = 1046), and Canada (n = 1935). Measurements Participants' survey responses indicated if they were current daily or weekly smokers and had visited an HP in the past year. Among those participants, further questions asked participants to report (1) whether NVPs were discussed, (2) who raised the topic, (3) advice received on use of NVPs and (4) advice received on quitting smoking. Findings Among the 6615 smokers who visited an HP in the last year, 6.8% reported discussing NVPs with an HP and 2.1% of smokers were encouraged to use an NVP (36.1% of those who had a discussion). Compared with Australia (4.3%), discussing NVPs with an HP was more likely in the United States [8.8%, odds ratio (OR) = 2.15, 95% confidence interval (CI) = 1.41–3.29] and Canada (7.8%, OR = 1.87, 95% CI = 1.26–2.78). Smokers in Australia were less likely to discuss NVPs than smokers in England (6.2%), although this was not statistically significant (OR = 1.47, 95% CI = 0.98–2.20). Overall, the prevalence of HPs recommending NVPs was three times more likely in the United States than in Australia (OR = 3.07, 95% CI = 1.45–6.47), and twice as likely in Canada (OR = 2.28, 95% CI = 1.06–4.87) than in Australia. Australia and England did not differ (OR = 1.76, 95% CI = 0.83–3.74). Just over half (54%) of respondents brought up NVPs themselves; there were no significant differences among countries. Conclusions: Discussions in Australia, Canada, England, and the United States between smokers and health professionals about nicotine vaping products appear to be infrequent, regardless of the regulatory environment. A low percentage of health professionals recommended vaping products. This was particularly evident in Australia, which has the most restrictive regulatory environment of the four countries studied. [ABSTRACT FROM AUTHOR]

Background and aims Effective strategies are needed to address dramatic increases in hepatitis C virus (HCV) infection among people who inject drugs (PWID) in rural settings of the United States. We determined the required scale-up of HCV treatment with or without scale-up of HCV prevention interventions to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025 and 2030 in a rural US setting. Design An ordinary differential equation model of HCV transmission calibrated to HCV epidemiological data obtained primarily from an HIV outbreak investigation in Indiana. Setting Scott County, Indiana (population 24 181), USA, a rural setting with negligible baseline interventions, increasing HCV epidemic since 2010, and 55.3% chronic HCV prevalence among PWID in 2015. Participants PWID. Measurements Required annual HCV treatments per 1000 PWID (and initial annual percentage of infections treated) to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025/30, either with or without scaling-up syringe service programmes (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without re-treatment of re-infections, and whether greater intervention scale-up was required due to the increasing epidemic in this setting. Findings To achieve a 90% reduction in incidence and prevalence by 2030, without MAT and SSP scale-up, 159 per 1000 PWID (initially 24.9% of infected PWID) need to be HCV-treated annually. However, with MAT and SSP scaled-up, treatment rates are halved (89 per 1000 annually or 14.5%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (19.9%) need treatment annually. These treatment requirements are threefold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment. Conclusions Combined scale-up of hepatitis C virus treatment and prevention interventions is needed to decrease the increasing burden of hepatitis C virus incidence and prevalence in rural Indiana, USA, by 90% by 2025/30. [ABSTRACT FROM AUTHOR]

Aims To examine the transitions in smoking status among non-daily smokers who transitioned to daily or former smokers or remained as non-daily smokers during a 12-month period. We analyzed factors associated with these transitions, including the use of cigars and smokeless tobacco (SLT). Design Secondary data analyses using pooled data from the 2003, 2006/07 and 2010/11 Tobacco Use Supplements to the Current Population Survey (TUS-CPS). Setting United States. Participants Self-respondents aged 18+ who have smoked for more than 5 years and were non-daily smokers 12 months before the interview ( n = 13 673, or 14.5% of current smokers). Measurements Multinomial logistic regression model to determine the correlates of non-daily to daily, stable non-daily and non-daily to former smoking transitions among non-daily smokers at baseline. The model controlled for socio-demographic factors and the use of cigars and SLT. Findings Of the adults in our sample, 2.6% were non-daily smokers at baseline. Among these, 69.7% remained non-daily smokers (stable non-daily smokers), 18.4% became daily smokers (non-daily to daily smokers) and 11.9% quit smoking (non-daily to former smokers) after 12 months. The non-daily to daily versus stable non-daily smoking transition was less likely among those who were aged 65+ ( P = 0.018), male ( P < 0.001), Hispanic ( P < 0.001), with an income of $25 000-49 999 or ≥$75 000 and current users of SLT ( P = 0.003), but more likely among those without a college degree compared with the appropriate reference group. The non-daily to former versus stable non-daily smoking transition was less likely among those aged 25+, male ( P = 0.013), non-Hispanic Asian ( P = 0.032), without a college degree, widowed/divorced/separated ( P = 0.013) or never married ( P = 0.011) and current users of cigars ( P = 0.003) compared with the appropriate reference group. Conclusions While more than two-thirds of non-daily smokers in the United States remain as such after 12 months, others become daily smokers or quit. The likelihood of remaining stable non-daily smokers and of transition from non-daily to daily and non-daily to former smokers is associated with socio-demographic factors and current use of cigars and smokeless tobacco. [ABSTRACT FROM AUTHOR]

Aims To determine whether abstinence or relapse on a quit attempt in the previous year is associated with current depressive symptoms. Design Prospective cohort with approximately annual waves. Mixed-effect logistic regressions tested whether time 2 (T2) quitting status was associated with reporting symptoms at T2, and whether time 1 (T1) symptoms moderated this relationship. Setting Waves 5-8 of the Four-Country International Tobacco Control Study: a quasi-experimental cohort study of smokers from Canada, the United States, the United Kingdom and Australia. Participants A total of 6978 smokers who participated in telephone surveys. Measurements T1 and T2 depressive symptoms in the last 4 weeks were assessed with two screening items from the PRIME-MD questionnaire. Quitting status at T2: (1) no attempt since T1; (2) attempted and relapsed; and (3) attempted and abstinent at T2. Findings Compared with no attempt, relapse was associated with reporting T2 symptoms [odds ratio (OR) = 1.46, 95% confidence interval (CI) = 1.33, 1.59]). Associations between T2 quitting status and T2 symptoms were moderated by T1 symptoms. Relapse was associated positively with T2 symptoms for those without T1 symptoms (OR = 1.71, 95% CI = 1.45, 2.03) and those with T1 symptoms (OR = 1.45, 95% CI = 1.23, 1.70). Abstinence was associated positively for those without T1 symptoms (OR = 1.37, 95% CI = 1.10, 1.71) and negatively for those with T1 symptoms (OR = 0.74, 95% CI = 0.59, 0.94). Age moderated these associations significantly. Relapse did not predict T2 symptoms for those aged 18-39 irrespective of T1 symptoms. The negative effect of abstinence on T2 symptoms for those with T1 symptoms was significant only for those aged 18-39 (OR = 0.61, 95% CI = 0.40, 0.94) and 40-55 (OR = 0.58, 95% CI = 0.40, 0.84). The positive effect of abstinence on T2 symptoms for those without T1 symptoms was significant only for those aged more than 55 (OR =1.97, 95% CI = 1.35, 2.87). Conclusions Most people who stop smoking appear to be at no greater risk of developing symptoms of depression than if they had continued smoking. However, people aged more than 55 who stop smoking may be at greater risk of developing symptoms of depression than if they had continued smoking. [ABSTRACT FROM AUTHOR]

To investigate changes in population smoking prevalence in jurisdictions which have implemented comprehensive smoke-free legislation, taking into account long-term trends in smoking behaviour. Interrupted time series analysis of population-level survey data using segmented regression. Twenty-one countries, American states or Canadian provinces which have implemented comprehensive smoke-free legislation. Respondents sampled in large representative surveys of smoking prevalence. For each jurisdiction, segmented regression models quantify any upwards or downwards trend in smoking prevalence prior to the introduction of smoke-free legislation, any immediate change in the level of smoking prevalence at the time smoke-free legislation was introduced, and any change in the trend in smoking prevalence post-legislation compared to the pre-legislation period. In all but three locations there was a statistically significant decline in smoking prevalence prior to the introduction of smoke-free legislation. In two locations, Washington and the Republic of Ireland, there was an immediate decline in the level of smoking prevalence at the introduction of legislation. In six American states there was a significant change in the rate of decline in smoking prevalence, with smoking prevalence declining more steeply in the post-legislation period compared to the pre-legislation period. No change in the level or trend of population smoking prevalence was seen in 13 of the 21 locations studied. The introduction of comprehensive smoke-free legislation has increased the rate at which smoking prevalence was declining in some locations, but in the majority of jurisdictions had no measureable impact on existing trends in smoking prevalence. [ABSTRACT FROM AUTHOR]