Tobacco-free nicotine pouch use in Great Britain: a representative population survey 2020-2021

Characterising smoking and nicotine use behaviours among women of reproductive age: a 10-year population study in England

BACKGROUND

Tobacco smoking affects women's fertility and is associated with substantial risks of adverse pregnancy outcomes. This study explored trends by socioeconomic position in patterns of smoking, use of non-combustible nicotine products, and quitting activity among women of reproductive age in England.

METHODS

Data come from a nationally representative monthly cross-sectional survey. Between October 2013 and October 2023, 197,266 adults (≥ 18 years) were surveyed, of whom 44,052 were women of reproductive age (18-45 years). Main outcome measures were current smoking, vaping, and use of nicotine replacement therapy (NRT), heated tobacco products (HTPs), and nicotine pouches; mainly/exclusively smoking hand-rolled cigarettes and level of dependence among current smokers; past-year quit attempts among past-year smokers; and success of quit attempts among those who tried to quit. We modelled time trends in these outcomes, overall and by occupational social grade (ABC1 = more advantaged/C2DE = less advantaged).

RESULTS

Smoking prevalence among women of reproductive age fell from 28.7% [95%CI = 26.3-31.2%] to 22.4% [19.6-25.5%] in social grades C2DE but there was an uncertain increase from 11.7% [10.2-13.5%] to 14.9% [13.4-16.6%] in ABC1. By contrast, among all adults and among men of the same age, smoking prevalence remained relatively stable in ABC1. Vaping prevalence among women of reproductive age more than tripled, from 5.1% [4.3-6.0%] to 19.7% [18.0-21.5%], with the absolute increase more pronounced among those in social grades C2DE (reaching 26.7%; 23.3-30.3%); these changes were larger than those observed among all adults but similar to those among men of the same age. The proportion of smokers mainly/exclusively smoking hand-rolled cigarettes increased from 40.5% [36.3-44.9%] to 61.4% [56.5-66.1%] among women of reproductive age; smaller increases were observed among all adults and among men of the same age. Patterns on other outcomes were largely similar between groups.

CONCLUSIONS

Among women of reproductive age, there appears to have been a rise in smoking prevalence in the more advantaged social grades over the past decade. Across social grades, there have been substantial increases in the proportion of women of reproductive age who vape and shifts from use of manufactured to hand-rolled cigarettes among those who smoke. These changes have been more pronounced than those observed in the general adult population over the same period.

Tobacco-Free Nicotine Pouches and Their Potential Contribution to Tobacco Harm Reduction: A Scoping Review

Tobacco harm reduction (THR) refers to strategies designed to reduce the health risks associated with tobacco smoking but may involve continued use of nicotine and/or tobacco. Next-generation products (NGPs) are a THR alternative as they do not burn tobacco or produce smoke and deliver nicotine and have fewer and substantially lower levels of harmful chemicals compared to cigarettes. Tobacco‑free nicotine pouches (TFNPs) are an emerging category of nicotine‑containing oral products that do not combust or contain tobacco leaf. Similar to Swedish snus, TFNPs are placed between a user's lip and gum, and nicotine is absorbed through the oral mucosa rather than being inhaled. The aim of this scoping review was to systematically collate and evaluate published scientific evidence (cut‑off of 31 May 2023) identified from bibliometric databases investigating the potential of TFNPs to contribute to THR. Overall, studies examining chemical constituents indicated that the use of TFNPs may result in lower exposure to toxicants than other tobacco or nicotine-containing products, both combustible and non‑combustible. This reduction in toxicant exposure has been demonstrated by multiple human biomarker studies and in vitro toxicological assessments to translate to harm reduction potential in smokers switching to TFNPs. However, further study is warranted. At present, there is some evidence from human behavioral research that TFNPs can support either transitioning away from smoking or reducing cigarette consumption. Furthermore, TFNP use appears very much limited to current users of traditional tobacco products, and youth uptake has been limited. In conclusion, the findings of this review indicate that TFNPs have the potential to support THR efforts and may help inform evidence‑based regulation.

A Cross-Sectional Survey on Oral Nicotine Pouches: Characterizing Use-Motives, Topography, Dependence Levels, and Adverse Events

INTRODUCTION

Oral nicotine pouches (ONPs) contain a crystalized nicotine powder instead of tobacco leaves. ONPs come in a variety of flavors and are often marketed as "tobacco-free," but research on ONP use-motivations and related experiences is limited.

AIMS AND METHODS

This cross-sectional web-based survey collected self-report data on ONP use-characteristics (eg, frequency), brands and flavors used, use-motivations, dependence (Fagerström Test for Nicotine Dependence-Smokeless Tobacco [FTND-ST]), and ONP-related adverse events (AEs) experienced.

RESULTS

The sample included 118 adults who reported current (past 30-day) ONP use. On average (SD), participants reported ONP use on 13 (6) days during the past month. Most participants (% of the sample) also reported the use of tobacco cigarettes (74%) and/or electronic cigarettes (53%) during the past month. Zyn (27%) and Lucy (19%) were the most currently used ONP brands with mint (23%) and tobacco (16%) as the most currently used flavors. The availability of preferred flavors was the most frequently reported (31%) ONP use-motivation. The sample demonstrated significant dependence levels (FTND-ST = 7, SD = 2). Reported AEs included mouth lesions (48%), upset stomach (39%), sore mouth (37%), sore throat (21%), and nausea (9%). Results should be interpreted in the context of study limitations, including using a relatively small and homogeneous online convenience sample. Acknowledging the limitations, this sample was deemed appropriate to include considering the novelty of the findings, the dearth of related research, and the necessity of examining foundational ONP use-characteristics (eg, topography, AEs); however, future research should consider recruiting larger and more generalizable samples.

CONCLUSIONS

The availability of preferred flavors was a key ONP use-motivation in this sample. Mint and tobacco were the most currently used flavors, with Zyn and Lucy being the most currently used ONP brands. Participants reported dependence and a substantial number of ONP-related AEs. Nationally representative surveys should investigate ONP use along with outcomes included in the current study (eg, AEs) to inform ONP surveillance and policy development efforts.

IMPLICATIONS

This study is among the first to assess reasons for initiating/maintaining ONP use as well as other relevant use-experiences (eg, AEs, dependence). These results highlight the role of flavors and nicotine dependence in ONP use, which are important considerations for informing ONP regulations.

Associations of prevalence of e-cigarette use with quit attempts, quit success, use of smoking cessation medication, and the overall quit rate among smokers in England: a time-series analysis of population trends 2007-2022

INTRODUCTION

This study aimed to: (i) provide up-to-date estimates of how changes in prevalence of e-cigarette use have been associated with changes in smoking cessation activities and use of licensed treatments among smokers in England; and (ii) explore any changes in these associations over time.

METHODS

Data were aggregated quarterly on 67,548 past-year smokers between Q1-2007 and Q4-2022. Explanatory variables were prevalence of (i) current e-cigarette use among smokers and (ii) e-cigarette use during a quit attempt. Outcomes were rates of quit attempts and overall quits among past-year smokers, and the quit success rate and use of licensed treatments among those who made a quit attempt.

RESULTS

The success rate of quit attempts increased by 0.040% (95%CI 0.019; 0.062) for every 1% increase in the prevalence of e-cigarette use during a quit attempt. No clear evidence was found for an association between current e-cigarette use and the quit attempt rate (Badj=0.008 [95%CI -0.045; 0.061]) or overall quit rate (Badj=0.063 [-0.031; 0.158]); or between use of e-cigarettes during a quit attempt and the overall quit rate (Badj=0.030 [-0.054; 0.114]), use of prescription medication (varenicline/bupropion/NRT: Badj=-0.036 [-0.175; 0.102]), or use of over-the-counter NRT (Badj=-0.052 [-0.120; 0.015]). There was no clear evidence this pattern of associations has changed substantially over time.

CONCLUSIONS

Changes in prevalence of e-cigarette use in England through to 2022 have been positively associated with the success rate of quit attempts but not clearly associated with the quit attempt rate, overall quit rate, or use of licensed smoking cessation treatments.

IMPLICATIONS

If the association between the increase in e-cigarette use and the quit success rate is causal, then the use of e-cigarettes in quit attempts has helped in the region of 30,000 to 50,000 additional smokers in England to successfully quit each year since they became popular in 2013, over and above the number who were quitting before the advent of e-cigarettes.

Nicotine pouches: a review for the dental team

Nicotine pouches are tobacco-free products that are becoming increasingly popular in the UK. They are held between the user's lip and gum to provide a source of nicotine. This article describes the composition of nicotine pouches, the legality surrounding their production and sale, patterns of use and explores possible oral and general health effects of their usage.

Applications of biomarkers of exposure and biological effects in users of new generation tobacco and nicotine products: Tentative proposals

Despite efforts to eliminate smoking, more than 1 billion people worldwide continue to use combustible cigarettes through choice or inability to quit. With an associated 8 million deaths, the provision of noncombustible tobacco and nicotine products that smokers will accept to replace combustible cigarettes can lessen harm. However, most of these products have entered the market only in the past 20 years. Therefore, particularly for some smoking-related diseases, epidemiological studies to test harm reduction potential are only now becoming feasible. For cancer and chronic obstructive pulmonary disease, around two decades of data might be required. In this article, we discuss how the use of biomarkers might be applied to supplement epidemiological research for regulators. We further discuss how health providers and insurers can keep up with the rapid changes in biomarker research and recognize these reduced risks.

Impact of Heated Tobacco Products, E-Cigarettes, and Combustible Cigarettes on Small Airways and Arterial Stiffness

Smoking cessation is difficult but maintaining smoke-free without nicotine replacement therapy is even harder. During the last few years, several different alternative products, including heated tobacco products (HTP), have been introduced to the market. In this study, we investigated the acute effects of IQOSTM and gloTM (two HTP) consumption on small airway function and arterial stiffness in a head-to-head design, comparing them to combustible cigarettes, nicotine-free e-cigarettes and a sham smoking group. Seventeen healthy occasional smokers were included in a single-center, five-arm, crossover study. The parameters of small airway function and hemodynamics were collected at several time points before and after consumption using Mobil-O-Graph™ (I.E.M., Stolberg, Germany) and TremoFlo® c-100 (THORASYS Thoracic Medical Systems Inc., Montreal, QC, Canada). Small airway obstruction and resistance were both significantly increased after the consumption of cigarettes and substitute products. All products containing nicotine led to similar significant increases in blood pressure and arterial stiffness. Hemodynamic parameters were also increased after the consumption of e-cigarettes without nicotine, but compared to nicotine-containing products, the increase was shorter and weaker. We conclude that, although it has yet to be determined why, HTP have acute harmful effects on small airway function, possibly even exceeding the effects of combustible cigarettes. Like other nicotine-containing products, HTP leads to a nicotine-related acute increase in arterial stiffness and cardiovascular stress, similar to combustible cigarettes, which associates these products with an increased cardiovascular risk.

How has Expenditure on Nicotine Products Changed in a Fast-Evolving Marketplace? A Representative Population Survey in England, 2018-2022

INTRODUCTION

In the last 5 years, there has been a dramatic shift in the types of nicotine products being purchased. This study aimed to estimate how much users spend on types of cigarettes and alternative nicotine products (e-cigarettes, nicotine replacement therapy (NRT), heated tobacco, and nicotine pouches) and describe changes between 2018 and 2022.

AIMS AND METHODS

Monthly representative cross-sectional survey in England. 10 323 adults who smoked cigarettes or used alternative nicotine reported their average weekly expenditure on these products, adjusted for inflation.

RESULTS

Smokers spent £20.49 [95% CI = 20.09-20.91] on cigarettes each week (£27.66 [26.84-28.50] and £15.96 [15.49-16.28] among those who mainly smoked manufactured and hand-rolled cigarettes, respectively), e-cigarette users spent £6.30 [5.99-6.55] (£8.41 [7.17-9.78], £6.42 [5.58-7.39], and £5.93 [5.64-6.30] among those who mainly used disposable, pod, and refillable devices, respectively), NRT users £6.11 [5.53-6.69], and heated tobacco users £13.87 [9.58-20.09]. Expenditure on cigarettes grew by 10% from September 2018 to July 2020, then fell by 10% from July 2020 to June 2022. These changes coincided with a 13% reduction in cigarette consumption and a 14% increase in the proportion mainly smoking hand-rolled cigarettes. Expenditure on e-cigarettes was stable between 2018 and late 2020, then rose by 31% up to mid-2022. Expenditure on NRT increased slowly in 2018-2020 (+4%) and more quickly thereafter (+20%).

CONCLUSIONS

Inflation-adjusted expenditure on cigarettes has fallen since 2020, such that the average smoker in England currently spends the same on cigarettes each week as in 2018. This has been achieved by smoking fewer cigarettes and switching to cheaper hand-rolled cigarettes. Expenditure on alternative nicotine has increased above inflation; users spent around a third more on these products in 2022 than between 2018-2020.

IMPLICATIONS

People in England continue to spend substantially more on smoking cigarettes than using alternative nicotine products. The average smoker in England spends around £13 a week (~£670 a year) more than people using only e-cigarettes or NRT. The average expenditure on manufactured cigarettes is double that of hand-rolled cigarettes.

Nicotine pouch awareness, use and perceptions among young adults from six metropolitan statistical areas in the United States

INTRODUCTION

Nicotine pouches, which emerged in the US in 2016 and are marketed as 'tobacco-free', may appeal to young adults. This study examined young adults' nicotine pouch awareness, use, use intentions, and related factors.

METHODS

We analyzed Spring 2022 survey data from 942 young adults recruited via social media from six US cities (mean age=27.61 years, 34.3% men, 33.1% racial/ethnic minority) to characterize nicotine pouch awareness, ever use, use intentions, exposure, and perceptions.

RESULTS

Nicotine pouch awareness and ever use were reported by 34.6% and 9.8%, respectively. Males (AOR=1.79; 95% CI: 1.33-2.38), non-White participants (vs White; AOR=1.64; 95% CI: 1.04-2.61), and those using cigarettes (AOR=2.67; 95% CI: 1.63-4.38), e-cigarettes (AOR=2.28; 95% CI: 1.57-3.31), and smokeless tobacco (SLT) (AOR=14.46; 95% CI: 1.81-115.61) had greater odds of awareness. Among those aware of nicotine pouches, males (AOR=2.27; 95% CI: 1.33-3.85), White participants (vs Asian; AOR=0.40; 95% CI: 0.17-0.94), and SLT users (AOR=4.90; 95% CI: 1.26-18.98) had greater odds of ever use; being male (B=0.39; 95% CI: -0.67 - -0.12) and using SLT (B=1.73; 95% CI: 1.10-2.36) predicted greater use intentions. Overall, 31.4% reported past-month advertising exposure, most often via tobacco retailers (67.3%). Ever users most commonly purchased them at gas stations (46.7%). The most frequently reported use motives were to quit combusted tobacco (16.8%) and reduce tobacco smell (15.4%). Nicotine pouches were perceived as less harmful and less addictive than cigarettes, e-cigarettes, and SLT, and more socially acceptable than cigarettes and SLT.

CONCLUSIONS

Young adults were exposed to advertising, accessed nicotine pouches via various sources, and perceived these products favorably. Marketing and use surveillance is needed to monitor their impact on those likely to use them (e.g. males, SLT users).

Awareness and use of short-fill e-liquids by youth in England in 2021: findings from the ITC Youth Tobacco and Vaping Survey

BACKGROUND

Refillable e-cigarettes were popular among youth in England in 2021. The UK Tobacco and Related Products Regulations (TRPR) limits e-liquids to 20 mg/mL of nicotine in a 10 mL bottle. Short-fill e-liquids, which are not covered by TRPR regulations, are typically nicotine-free and come in larger, underfilled bottles allowing customisation with the addition of 'nicotine shots'. This paper investigates awareness, use, and reasons for use of short-fill e-liquids among youth in England.

METHODS

Data are from the online 2021 International Tobacco Control Youth Survey, comprising 4224 youth (aged 16-19 years) in England. Weighted logistic regression models investigated associations between awareness and past 30-day use of short-fills by smoking status, vaping status, nicotine strength vaped and participant demographics. Reasons for use were also reported.

RESULTS

Approximately one-quarter (23.0%) of youth in England reported awareness of short-fill e-liquids. Among youth who had vaped in the past 30 days, 22.1% had used short-fills in the past 30 days; use was most prevalent among those who were also smoking (43.2%) and those who reported usually vaping nicotine concentrations of 2.1% (21 mg/mL) or more (40.8%). 'Convenience of a bigger bottle' was the most selected reason for use (45.0%), followed by 'less expensive than regular e-liquids' (37.6%).

CONCLUSIONS

Awareness of short-fills was common among youth in 2021, including among those who had never vaped or smoked. Among youth who vaped in the past 30 days, short-fill use was more prevalent among those who also smoked and those who vaped nicotine-containing e-liquids. Integration of short-fill products into existing e-cigarette regulations should be considered.

Nicotine Pouch: Awareness, Beliefs, Use, and Susceptibility among Current Tobacco Users in the United States, 2021

Little is known about awareness, beliefs, and use of nicotine pouches (NPs). Data from 1583 U.S. adult (age ≥ 21 years) current tobacco users were collected in 2021. Respondents self-reported NP awareness, beliefs, use, and susceptibility as well as current tobacco product use and socio-demographics. We used weighted logistic and multinomial regression models to explore the associations between these variables. Overall, 46.6% of U.S. adult current tobacco users were aware of, 16.4% had ever used, and 3.0% currently used NPs. Younger individuals (vs. 61+ years) were more likely to have ever heard of NPs, while Black individuals (vs. White) were less likely to have ever heard of NPs. Individuals younger than 45 years (vs. 61+ years) and those using smokeless tobacco products (vs. non-users) were more likely to have ever used NPs. Additionally, younger than 45 years (vs. 61+ years) and current use of certain tobacco products (e.g., smokeless) were associated with current NP use. Holding favorable beliefs about NPs was associated with susceptibility to and more advanced NP use statuses (p < 0.05). Continuous surveillance of NP use and beliefs is important.

Impact of Chewing Bags, E-Cigarettes, and Combustible Cigarettes on Arterial Stiffness and Small Airway Function in Healthy Students

Several substitute products are discussed as a healthier alternative to smoking, thereunder e-cigarettes and smokeless tobacco products, e.g., chewing bags, which are increasingly used in this context. We investigated the acute effects of chewing bags compared to combustible cigarettes and e-cigarettes with and without nicotine on small airways and arterial stiffness in a head-to-head design. This single-center, four-arm cross-overstudy included 20 healthy occasional smokers (25 ± 0.6 years). On four test days, participants consumed one product per day. Before, during, and after consumption, peripheral and central hemodynamic as well as arterial stiffness parameters were measured by Mobil-O-Graph™ (I.E.M., Germany). Resistance and small airway function were assessed by tremoFlo® c-100 (THORASYS Thoracic Medical Systems Inc.). The combustible cigarette and the e-cigarettes with and without nicotine significantly increased the resistance of the small airways (p < 0.05), while chewing bags had no effect. All nicotine containing products (e-cigarette with nicotine, combustible cigarette, chewing bag) as well as the e-cigarette without nicotine significantly increased parameters of hemodynamic and arterial stiffness. Changes in blood pressure and arterial stiffness were similar after smoking, vaping, and using chewing bags. We conclude that e-cigarettes and combustible cigarettes have similar acute harmful effects on small airway dysfunction. All nicotine containing products are associated with an increased cardiovascular risk compared with no product use.

An Analysis of Nicotine Pouch Use by Middle School and High School Students Surveyed by the National Youth Tobacco Survey in 2021 and a Review of the Literature

OBJECTIVES

The use of alternative nicotine products by middle and high school students is a growing concern due to industry marketing techniques, availability, and popularity of new products, and ambiguous nicotine concentrations. The 2021 National Youth Tobacco Survey (NYTS) provides information about the frequency, and characteristics of middle, and high school students who have used nicotine pouches.

METHODS

The National Youth Tobacco Surveys provide important information about the frequency of use of tobacco and alternative nicotine products by a representative sample of students in schools in the United States. The 2021 survey included questions about the use of nicotine pouches/dissolvable tobacco products. The results from the survey were analysis using descriptive statistics, and logistic regression to model the association between the use of these alternative nicotine products, and the use of electronic cigarettes or the use of conventional cigarettes.

RESULTS

A total of 20 413 students participated in the survey year 2021; 17 842 were included in the final data analysis. Their ages ranged from 9 to 18+. Identified risk factors for the use of alternative nicotine products included race, and age. The adjusted odds ratio (OR) was lower in non-Hispanic Black and Hispanic students, as compared to non-Hispanic White students. Older students had a substantially higher risk of using nicotine/dissolvable tobacco products, specifically, compared to students less than or equal to 13 years old. The OR increased 174% (OR: 2.74; 1.70-4.41) in 17-year-old students. The perception of harm associated with electronic cigarettes increased the likelihood of using alternative nicotine products. Students who did not smoke cigarettes (OR: 0.39; 0.27-0.56) or did not smoke electronic cigarettes (OR: 0.20; 0.18-0.40) had significantly lower OR for using alternative nicotine products.

CONCLUSIONS

The 2021 National Youth Tobacco Survey indicates that a relatively small percentage of middle school and high school student have used nicotine pouches. However, with the increase in new, alternative tobacco products, understanding adolescent use in comparison to other tobacco products is an important trend to monitor.

Profiles of tobacco product use and related consumer characteristics in the US and Israel: A multiple-group latent class analysis

Despite tobacco marketing diversification, limited research has examined use profiles across countries, particularly in relation to consumer values (e.g. appeal of innovation, conscientiousness). Using 2021 data, latent class analysis assessed past-month use of seven tobacco products (cigarettes, electronic cigarettes [e-cigarettes], heated tobacco products, cigars, hookah, pipe, smokeless) among adults reporting past-month use in the United States (US n = 382) and Israel (n = 561). Multivariable multinomial regression examined consumer values and sociodemographics in relation to country-specific class membership. US classes included: primarily cigarette 58.1%; e-cigarette-no cigarette 17.5%; primarily cigar 14.9%; and poly-product 9.9%. Higher innovation correlated with e-cigarette-no cigarette and poly-product (vs. primarily cigarette) use. Other correlates included being: younger with e-cigarette-no cigarette; male, Black, and more educated with primarily cigar; and Black and Asian (vs. White) with poly-product. Israel classes included: primarily cigarette 39.0%; moderate poly-product 40.3%; high poly-product 13.4%; and hookah 7.3%. Lower conscientiousness correlated with moderate poly-product (vs. primarily cigarette) use; higher innovation correlated with high poly-product; lower innovation correlated with hookah. Other correlates included being: younger, male, and more educated with moderate poly-product; male and sexual minority with high poly-product; and Arab with hookah. Tobacco consumer segments within and across countries likely reflect different consumer values and industry marketing targets.

Biomarkers of Exposure and Potential Harm in Exclusive Users of Nicotine Pouches and Current, Former, and Never Smokers: Protocol for a Cross-sectional Clinical Study

Background

Tobacco harm reduction (THR) aims to reduce the health burden of cigarettes by encouraging smokers to switch to using alternative tobacco or nicotine products. Nicotine pouches (NPs) are smokeless, tobacco-free, oral products that may be beneficial as part of a THR strategy.

Objective

This 2-center, cross-sectional confinement study conducted in Denmark and Sweden aimed to determine whether biomarkers of exposure (BoEs) to tobacco toxicants and biomarkers of potential harm (BoPHs) in exclusive users of NPs show favorable differences compared with current smokers.

Methods

Participants were healthy NP users (target n=100) and current, former, or never smokers (target n=40 each), as confirmed by urinary cotinine and exhaled carbon monoxide concentrations. During a 24-hour confinement period, participants were asked to use their usual product (NP or cigarette) as normal, and BoEs and BoPHs were measured in blood and 24-hour urine samples, with compliance determined using anabasine, anatabine, and N-(2-cyanoethyl)valine. BoEs and BoPHs were compared between NP users and current, former, and never smokers. Urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (BoE to nicotine-derived nitrosamine ketone) and urinary 8-epi-prostaglandin F2α type III, exhaled nitric oxide, blood carboxyhemoglobin, white blood cell count, soluble intercellular adhesion molecule-1, and high-density lipoprotein cholesterol (BoPHs) were evaluated as primary outcomes. Other measures included urinary 11-dehydrothromboxane B2, forced expiratory volume, carotid intima-media thickness, self-reported quality of life, and oral health.

Results

The results of this study were received in mid-2022 and will be published in late 2022 to early 2023.

Conclusions

The results of this study will provide information on toxicant exposure and biomarkers associated with the development of smoking-related diseases among users of NPs compared with smokers, as well as on the potential role of NPs in THR.

Trial Registration

International Standard Randomised Controlled Trial Number (ISRCTN) ISRCTN16988167; https://www.isrctn.com/ISRCTN16988167

International Registered Report Identifier (IRRID)

DERR1-10.2196/39785