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Brief report
News coverage of the E-cigarette, or Vaping, product use Associated Lung Injury (EVALI) outbreak and internet searches for vaping cessation
  1. Eric C Leas1,2,
  2. Alicia L Nobles1,2,
  3. Theodore L Caputi3,
  4. Mark Dredze4,
  5. Shu-Hong Zhu1,
  6. Joanna E Cohen5,
  7. John W Ayers1,2
  1. 1 School of Medicine, University of California San Diego, La Jolla, California, USA
  2. 2 Center for Data Driven Health, Qualcomm Institute, La Jolla, California, USA
  3. 3 University College Cork National University of Ireland, Cork, Ireland
  4. 4 Computer Science, Johns Hopkins University, Baltimore, Maryland, USA
  5. 5 Institute for Global Tobacco Control, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
  1. Correspondence to Dr John W Ayers, Emergency Medicine, Children's Hospital Boston (Harvard), Boston, MA 02115, USA; ayers.john.w{at}gmail.com

Abstract

Background In the latter half of 2019, an outbreak of pulmonary disease in the USA resulted in 2807 hospitalisations and 68 deaths, as of 18 February 2020. Given the severity of the outbreak, we assessed whether articles during the outbreak era more frequently warned about the dangers of vaping and whether internet searches for vaping cessation increased.

Methods Using Tobacco Watcher, a media monitoring platform that automatically identifies and categorises news articles from sources across the globe, we obtained all articles that (a) discussed the outbreak and (b) primarily warned about the dangers of vaping. We obtained internet search trends originating from the USA that mentioned ‘quit’ or ‘stop’ and ‘e cig(s),’ ‘ecig(s),’ ‘e-cig(s),’ ‘e cigarette(s),’ ‘e-cigarette(s),’ ‘electronic cigarette(s),’ ‘vape(s),’ ‘vaping’ or ‘vaper(s)’ from Google Trends (eg, ‘how do I quit vaping?’). All data were obtained from 1 January 2014 to 18 February 2020 and ARIMA models were used with historical trends to forecast the ratio of observed to expected search volumes during the outbreak era.

Results News of the vaping-induced pulmonary disease outbreak was first reported on 25 July 2019 with 195 articles, culminating in 44 512 articles by 18 February 2020. On average, news articles warning about the dangers of vaping were 130% (95% prediction interval (PI): −15 to 417) and searches for vaping cessation were 76% (95% PI: 28 to 182) higher than expected levels for the days during the period when the sources of the outbreak were unknown (25 July to 27 September 2019). News and searches stabilised just after the US Centers for Disease Control and Prevention reported that a primary source of the outbreak was an additive used in marijuana vapes on 27 September 2019. In sum, there were 12 286 articles archived in Tobacco Watcher primarily warning about the dangers of vaping and 1 025 000 cessation searches following the outbreak.

Conclusion The vaping-induced pulmonary disease outbreak spawned increased coverage about the dangers of vaping and internet searches for vaping cessation. Resources and strategies that respond to this elevated interest should become a priority among public health leaders.

  • surveillance and monitoring
  • electronic nicotine delivery devices
  • public policy

https://doi.org/10.1136/tobaccocontrol-2020-055755

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    Introduction

    Vaping has exploded in popularity in the USA1 2 with many hopeful that e-cigarettes could be less harmful than smoking.3 The strategy the USA has adopted for vaping regulation has been less restrictive than some other countries4 and, potentially as a result, many US youth have begun using e-cigarettes under the presumption that they are less harmful than cigarettes.5

    However, a recent outbreak of pulmonary disease in the USA, which peaked in late 2019 and led to 2807 hospitalisations and 68 deaths as of 18 February 2020, may have influenced public perceptions of vaping products.6 While the investigation of cases is ongoing, the US Centers for Disease Control and Prevention (CDC) primarily linked the outbreak to an additive used in marijuana vaping solutions (vitamin E acetate) on 27 September 2019,7 introducing the potential for two distinct periods when the primary source of the outbreak was unknown and another when the primary source was known.

    Given the severity of the outbreak, we hypothesised that media coverage shifted to more frequently warn about the dangers associated with vaping and that the outbreak prompted increased interest in vaping cessation (as expressed internet searches for vaping cessation), especially when the outbreak source was unknown and health concerns may have generalised to all vapes include e-cigarettes. To test these hypotheses, we relied on two data sources: (1) Tobacco Watcher to track media coverage and (2) Google Trends to track internet searches vaping cessation. News media monitoring is an important strategy to assess agenda setting and what ideas are most likely at the top of the mind among the public to plan responses,8 including for tobacco control.9 Internet search query trends reveal what the public is potentially thinking or doing based on the content and timing of their queries10 and can serve as a rapid response data resource especially when no other data are available.11–13

    Methods

    Tobacco Watcher (www.tobaccowatcher.org) is a global media monitoring platform that automatically identifies and categorises tobacco-related articles from over 374 000 news websites. We searched the archive (including more than 950 000 articles from sources all throughout the world) using the ‘Analyses’ feature to describe trends in (a) outbreak coverage, which we defined as articles containing ‘vaping’ with ‘lung,’ ‘respiratory,’ ‘illness’ or ‘outbreak’ and (b) articles primarily warning about the dangers of vaping by using Tobacco Watcher’s automatic ‘warning’ categorisation (eg, articles that are believed to primarily warn about the dangers of product use) in combination with articles primarily about vaping products.14 We tracked Google searches (www.google.com/trends) originating from the USA that mentioned ‘quit’ or ‘stop’ in combination with ‘e cig(s),’ ‘ecig(s),’ ‘e-cig(s),’ ‘e cigarette(s),’ ‘e-cigarette(s),’ ‘electronic cigarette(s),’ ‘vape(s),’ ‘vaping’ or ‘vaper(s)’ as indicators of internet searches for vaping cessation (eg, ‘how do I quit vaping?’). News and searches were obtained from 1 January 2014 to allow for historical trends to inform our forecasts for expected volumes during the outbreak, through 18 February 2020, the last day of available data when analyses were performed.

    Both news and searches were measured on a relative scale for statistical analyses. Rates of news were calculated as the number of articles matching our search criterion (keyword searches or labelled as warning) on a given day divided by the total number of articles in Tobacco Watcher occurring on the same day (expressed as per cent). Search rates provided by Google were calculated as the number of searches occurring in the USA that matched the search criterion on a given day divided by the total number of searches on the same day (expressed as per 10 million). Total counts of news were calculated by summing the number of articles matching the search criteria for the outbreak period in Tobacco Watcher and Google search counts for the outbreak period were estimated using the rates provided by Google and estimates of total search volume derived from ComScore.com.

    Our analytical approach was quasi-experimental, describing coverage of the outbreak following the first day of outbreak coverage. To define post-period cutpoints, we relied on the CDC’s archive of press releases. We considered two periods. First, the period when the source of the outbreak was unknown (through 27 September 2019), and second, the period when the CDC named vitamin E acetate as a primary cause of the outbreak (27 September 2019 and onward).15 To test our hypotheses, we applied an ARIMA model16 to all historical data (from 1 January 2014) to forecast the expected article and search volumes and computed the ratio of observed to expected volumes along with prediction intervals (PIs), following the first day of outbreak coverage identified in the archive. We summarise the average increases for each period and highlight key days with the largest increases from the expected values in the outbreak era. We then used the ‘Smart History’ feature of Tobacco Watcher to explore focal stories on key days in the time trend (eg, a story might appear first in the Associated Press and be republished on dozens of news sites as exact or near duplicates) and described articles within those focal stories by their title and engagement on Facebook (ie, the total number of shares). All statistical analyses were performed using R V.3.6.1 (R Foundation).

    Results

    The first news mention of the outbreak archived in Tobacco Watcher was in 25 July 2019 ‘The Patch’ article entitled ‘8 Teens Suffer Damaged Lungs After Vaping’ (figure 1). One hundred ninety-five articles appeared on the day the first article broke and rapidly increased, peaking with 1089 articles on 25 September 2019, and culminating with 44 512 articles through 18 February 2020. Forty-three per cent of these articles were published prior to the CDC identifying a potential cause of the outbreak on 27 September 2019. Two prominent articles during the period were (1) an article entitled ‘journey of a tainted vape cartridge: from China’s labs to your lungs’ published on Leafly (a marijuana news site) that described one man’s illness case study and (2) Wall Street Journal published on 7 September 2019 citing the spread of the outbreak, each shared on Facebook 9366 and 6419 times, respectively. Fifty-seven per cent of all articles retrieved were published after the cause being officially determined, including the popular Vice story entitled ‘the vaping crisis has a new villain Dank Vapes’ that was shared 3476 times on Facebook and republished or covered in 83 additional news outlets/sites.

    Figure 1
    Figure 1

    News media timeline of the outbreak of vaping-induced pulmonary disease. (A) The cumulative article counts for news articles that mentioned ‘vaping’ and ‘lung,’ ‘respiratory,’ ‘illness’ or ‘outbreak’ as archived on Tobacco Watcher (www.tobaccowatcher.org). (B) The first news article describing the outbreak of vaping-induced pulmonary disease as preserved on the Tobacco Watcher platform. The article is accessible at the following link: https://tobaccowatcher.globaltobaccocontrol.org/articles/2aa6f72e-0ea0-3b66-93d8-9b8f55fda5cd/%23related-coverage.

    News articles that primarily warned about the dangers of vaping hit record highs following reports of the outbreak, increasing an average of 130% (95% PI: −15 to 417) above expected levels during the period when the cause of the outbreak was unknown (figure 2A,B). For 23 of the 64 days during this same period, there were significantly more articles than expected, ranging from 184% (95% PI: 5 to 505) more than expected on 8 September 2019 to 540% (95% PI: 136 to 1000) more than expected on 24 August 2019. News volumes stabilised near expected levels around the time when CDC identified that the source of the outbreak was likely linked to marijuana vapes (27 September 2019), although some spikes in news principally about the dangers of vaping episodically occurred. Overall, news remained slightly elevated during the period when the cause of the outbreak was potentially identified (27 September 2019 to 18 February 2020; 52%, 95% PI: −44 to 317). In sum, there were 12 286 articles primarily warning about the dangers of vaping that were archived in Tobacco Watcher in the entire post-outbreak period (25 July 2019 to 18 February 2020).

    Figure 2
    Figure 2

    Changes in news and internet searches following the outbreak of vaping-induced pulmonary disease. (A) Observed daily trend for news articles primarily warning about vaping from 1 January 2019 to 18 February 2020. (B) The ratio of the observed to the forecasted expected daily trend for news articles primarily warning about vaping and the 95% PI of this ratio, which incorporates the uncertainty of the forecast and is shaded in light blue, for the period from the start of the outbreak (25 July 2019) to the end of the interval (18 February 2020). (C) Observed daily trend for vaping cessation Google searches from 1 January 2019 to 18 February 2020. (D) The ratio of the observed to the forecasted expected daily trend for vaping cessation Google searches and the 95% PI of this ratio, which incorporates the uncertainty of the forecast and is shaded in light blue, for the period from the start of the outbreak (25 July 2019) to the end of the interval (18 February 2020). Note: Trends from 1 January 2014 prior to 25 July 2019 were used to develop a forecast of expected values for the outbreak era (presented in panels B and D), but trimmed in the time series we presented in panels A and C to improve the visibility of the trend. 95% PI, 95% prediction interval.

    Vaping cessation searches increased an average of 76% (95% PI: 28 to 182) above expected levels during the post-outbreak period when the source of the outbreak was unknown (figure 2C,D). For 35 of the 64 days, queries were significantly greater than expected, ranging from 43% (95% PI: 4 to 129) more than expected on 23 August 2019 to 364% (95% PI: 236 to 647) more than expected on 12 September 2019. Queries began to stabilise around the time when CDC identified that the source of the outbreak was likely linked to marijuana vapes (27 September 2019), but remained an average of 32% (95% PI: −5 to 119) greater than the expected volumes during this period. In sum, there were 1 025 000 vaping cessation searches in the entire post-outbreak period.

    Discussion

    The vaping-induced pulmonary disease outbreak spawned both record-setting coverage about the dangers of vaping and internet searches for vaping cessation, the latter sustained long after the outbreak was first reported. Vaping cessation searches notably stabilised after the CDC identified that the source of the outbreak was likely linked to an additive used in marijuana vape solutions, which may suggest that much of the initial increase resulted from a generalised concern about the safety of all vaping products that later subsided. Nonetheless, over a million queries for vaping cessation occurred during this period, highlighting the need for an evidence base that informs clinical practice guidelines and fosters vaping cessation resources responsive to elevated demand.

    Consistent with our hypothesis, we observed an uptick in searches following the start of the vaping outbreak, suggesting that the outbreak may have motivated many vapers to search for vaping cessation resources. However, while receptive to behaviour change,17 the outbreak era searchers likely turned up empty-handed. Few free public health-sponsored resources exist for vaping (including online help-guides, chat support or telephone helplines), and the ones that did during the outbreak era had to compete with other for-profit industries that promoted cessation strategies that are counter to the evidence.18–20 Resources for vaping cessation need to be developed and become available for all Americans. One avenue for accomplishing this is adapting existing resources for cigarette smoking cessation. Future efforts will also need to consider that the majority of vapers are youth and young adults and thus be tailored to serve these populations.

    While pharmacotherapies when used in combination with behavioural counselling are considered the gold standard for smoking cessation,21 22 it is unclear whether these therapies will be similarly effective for vaping cessation. For instance, since vapers can vape multiple substances, including nicotine and marijuana, the types of cessation support may not be universal because the symptoms of withdrawal may not be the same across products. Even for a single vaped substance like nicotine, the variability in dosing across vapes (eg, high dosage tank devices) makes it difficult to effectively dose cessation therapies such as varenicline or nicotine replacement therapy.

    Once developed, vaping cessation resources must be effectively deployed, including promotion through social media, targeted search engine advertisements and earned news media. For instance, using the search trends we analysed, health agencies could execute targeted search query advertisements to promote new vaping cessation resources akin to the behavioural marketing practices currently and successfully used by businesses. Furthermore, it is critical that we educate vapers and the public at large even now about the dangers of vaping and the availability of resources to foster cessation to create an echo effect that builds on their organically elevated interest in vaping cessation. Campaigns might create a culture that is more accepting of the dangers of vaping and encourages strategies to quit vaping.

    There is added complexity given that the pulmonary disease outbreak the CDC has primarily attributed the outbreak to an additive in marijuana vapes, and many may have been prompted to quit vaping nicotine because of an unrelated event. This unintended positive effect (although at a substantial cost to those who died from the vaping illness outbreak) raises unaddressed but critically important questions about the unintended negative effects the marijuana vape industry has on tobacco control. Marijuana products are neither federally regulated for safety (even prior to the vaping illness outbreak 52 persons were poisoned by marijuana-derived products sold at one Utah outlet23) or marketing claims (retailers are allowed to make false health and safety claims and even target children).24 For instance, national retail giant MedMen even sells marijuana-branded high school varsity jackets calling back to the dark ages of tobacco control when children wore tobacco-branded clothing to public schools in the absence of any regulation.23 There is potential that the ‘wild west’ of marijuana regulation might engender growth in nicotine vaping as those subjected to false claims from the marijuana industry attribute those to nicotine products as well.24 Even evidence from the vaping illness outbreak suggests that these two might be related as many teens with pulmonary disease reported dual use of marijuana and nicotine vapes.7

    We should note a few potential limitations of our analysis. We could not identify the specific type of vaping products discussed in news or indicated in searches, although searches mirror many behavioural trends,25 including tobacco cessation.26 Also, sources of news could not be limited to US news sources using Tobacco Watcher. However, in this day and age, US consumers are frequently exposed to articles coming from international news sources (eg, BBC or The Guardian), so the global reach of Tobacco Watcher may actually be a strength. We could not determine the potential audience size for the news articles that we studied, since these readership numbers are proprietary information that news providers frequently do not share or mask in a way where the audience for any one article is unknown.

    To date, public health’s attention on vaping products has been largely discordant. While some have viewed vapes as cigarette smoking cessation aids,27 others have suggested that vaping is a gateway to initiation of smoking combustible cigarettes,28 and others have pointed to the potential dangers of vaping (including adverse events like the outbreak).29 As a result, there have been few calls for resources to foster vaping cessation. Following the outbreak of vaping illnesses, there has been widespread speculation about its potential public health implications30 and our study supplants speculation with data. Given the inherent lack of resources available to help vapers quit, fostering vaping cessation must become a public health priority, especially to meet the record setting demand for vaping cessation resources. Moreover, our study also raises important questions about the future of tobacco control in the era of unregulated marijuana retailing.

    What this paper adds

    • For the first time, we evaluate collateral population health implications of the recent outbreak of pulmonary disease linked to vaping. Our findings suggested that both news articles warning about the dangers of vaping and internet searches for vaping resources increased particularly in the time period when the source of the outbreak had not yet been linked to an additive used in marijuana vapes. The results highlight a need to meet a demand for resources for vaping cessation that has until now have largely been overlooked.

    Ethics statements

    Acknowledgments

    This research was funded in part by the Tobacco Related Diseases Research Program (28KT-004), Burroughs Wellcome Fund (Innovation in Regulatory Science), and Bloomberg Initiative to Reduce Tobacco Use. Dr Leas acknowledges salary support from grant R01CA234539 from the National Cancer Institute at the National Institutes of Health and grant 28IR-0066 from the Tobacco Related Diseases Research Program. Mr Caputi acknowledges support from the Marshall Scholarship program.

    References

    1. ↵
      2. Ayers JW ,
      3. Ribisl KM ,
      4. Brownstein JS
      . Tracking the rise in popularity of electronic nicotine delivery systems (electronic cigarettes) using search query surveillance. Am J Prev Med 2011;40:448–53.doi:10.1016/j.amepre.2010.12.007 pmid:http://www.ncbi.nlm.nih.gov/pubmed/21406279
      OpenUrlCrossRefPubMedWeb of Science
    2. ↵
      2. Ayers JW ,
      3. Althouse BM ,
      4. Allem J-P , et al
      . Revisiting the rise of electronic nicotine delivery systems using search query surveillance. Am J Prev Med 2016;50:e173–81.doi:10.1016/j.amepre.2015.12.008 pmid:http://www.ncbi.nlm.nih.gov/pubmed/26876772
      OpenUrlCrossRefPubMed
    3. ↵
      2. Cahn Z ,
      3. Siegel M
      . Electronic cigarettes as a harm reduction strategy for tobacco control: a step forward or a repeat of past mistakes? J Public Health Policy 2011;32:16–31.doi:10.1057/jphp.2010.41 pmid:http://www.ncbi.nlm.nih.gov/pubmed/21150942
      OpenUrlCrossRefPubMedWeb of Science
    4. ↵
      2. Kennedy RD ,
      3. Awopegba A ,
      4. De León E , et al
      . Global approaches to regulating electronic cigarettes. Tob Control 2017;26:440–5.doi:10.1136/tobaccocontrol-2016-053179 pmid:http://www.ncbi.nlm.nih.gov/pubmed/27903958
      OpenUrlAbstract/FREE Full Text
    5. ↵
      2. Strong DR ,
      3. Leas E ,
      4. Elton-Marshall T , et al
      . Harm perceptions and tobacco use initiation among youth in wave 1 and 2 of the population assessment of tobacco and health (path) study. Prev Med 2019;123:185–91.doi:10.1016/j.ypmed.2019.03.017 pmid:http://www.ncbi.nlm.nih.gov/pubmed/30878572
      OpenUrlPubMed
    6. ↵
      Outbreak of lung injury associated with the use of e-cigarette, or Vaping, products. Centers for Disease Control and Prevention 2020.
    7. ↵
      2. Blount BC ,
      3. Karwowski MP ,
      4. Morel-Espinosa M , et al
      . Evaluation of Bronchoalveolar Lavage Fluid from Patients in an Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - 10 States, August-October 2019. MMWR Morb Mortal Wkly Rep 2019;68:1040–1.doi:10.15585/mmwr.mm6845e2 pmid:http://www.ncbi.nlm.nih.gov/pubmed/31725707
      OpenUrlPubMed
    8. ↵
      2. Ayers JW ,
      3. Westmaas JL ,
      4. Leas EC , et al
      . Leveraging big data to improve health awareness campaigns: a novel evaluation of the great American Smokeout. JMIR Public Health Surveill 2016;2:e16.doi:10.2196/publichealth.5304 pmid:http://www.ncbi.nlm.nih.gov/pubmed/27227151
      OpenUrlPubMed
    9. ↵
      2. Davis RM
      . The role of the media in promoting and reducing tobacco use. U.S. dept. of health and HumanServices, National Institutes of health, National cancer Institute; 2008. table of contents only, 2008. Available: http://www.loc.gov/catdir/toc/fy1001/2008412745.html
    10. ↵
      2. Ayers JW ,
      3. Althouse BM ,
      4. Dredze M
      . Could behavioral medicine lead the web data revolution? JAMA 2014;311:1399–400.doi:10.1001/jama.2014.1505 pmid:http://www.ncbi.nlm.nih.gov/pubmed/24577162
      OpenUrlCrossRefPubMedWeb of Science
    11. ↵
      2. Leas EC ,
      3. Althouse BM ,
      4. Dredze M , et al
      . Big data sensors of organic advocacy: the case of Leonardo DiCaprio and climate change. PLoS One 2016;11:e0159885. doi:10.1371/journal.pone.0159885 pmid:http://www.ncbi.nlm.nih.gov/pubmed/27482907
      OpenUrlPubMed
    12. ↵
      2. Leas EC ,
      3. Dredze M ,
      4. Ayers JW
      . Ignoring data delays our reaction to emerging public health Tragedies like 13 reasons why. JAMA Psychiatry. Published online 2019.
    13. ↵
      2. Ayers JW ,
      3. Althouse BM ,
      4. Johnson M , et al
      . Circaseptan (Weekly) rhythms in smoking cessation considerations. JAMA Intern Med 2014;174:146–8.doi:10.1001/jamainternmed.2013.11933 pmid:http://www.ncbi.nlm.nih.gov/pubmed/24166181
      OpenUrlPubMed
    14. ↵
      2. Ayers JW ,
      3. Dredze M ,
      4. Leas EC , et al
      . Next generation media monitoring: global coverage of electronic nicotine delivery systems (electronic cigarettes) on Bing, Google and Twitter, 2013-2018. PLoS One 2018;13:e0205822. doi:10.1371/journal.pone.0205822 pmid:http://www.ncbi.nlm.nih.gov/pubmed/30388126
      OpenUrlPubMed
    15. ↵
      1. CDC
      . Hc products may play a role in outbreak of lung injury associated with e-cigarette use, or Vaping. centers for disease control and prevention, 2019. Available: https://www.cdc.gov/media/releases/2019/p0927-thc-vaping.html [Accessed 22 May 2020].
    16. ↵
      2. Hyndman RJ ,
      3. Khandakar Y
      . Automatic Time Series Forecasting: The forecast Package for R. J Stat Softw 2008;27.doi:10.18637/jss.v027.i03
    17. ↵
      2. Lambert SD ,
      3. Loiselle CG
      . Health information seeking behavior. Qual Health Res 2007;17:1006–19.doi:10.1177/1049732307305199 pmid:http://www.ncbi.nlm.nih.gov/pubmed/17928475
      OpenUrlCrossRefPubMedWeb of Science
    18. ↵
      2. Ayers JW ,
      3. Althouse BM ,
      4. Ribisl KM , et al
      . Digital detection for tobacco control: online reactions to the 2009 U.S. cigarette excise tax increase. Nicotine Tob Res 2014;16:576–83.doi:10.1093/ntr/ntt186 pmid:http://www.ncbi.nlm.nih.gov/pubmed/24323570
      OpenUrlCrossRefPubMedWeb of Science
    19. ↵
      2. Leas EC ,
      3. Cohen JE ,
      4. Ayers JW
      . A Philip Morris advertisement for its heated tobacco product IQOS sets a troubling precedent. Tob Control 2020;29:e168–70.doi:10.1136/tobaccocontrol-2019-055363
      OpenUrlFREE Full Text
    20. ↵
      2. Caputi TL ,
      3. Leas E ,
      4. Dredze M , et al
      . They're heating up: Internet search query trends reveal significant public interest in heat-not-burn tobacco products. PLoS One 2017;12:e0185735. doi:10.1371/journal.pone.0185735 pmid:http://www.ncbi.nlm.nih.gov/pubmed/29020019
      OpenUrlPubMed
    21. ↵
      2. Leas EC ,
      3. Pierce JP ,
      4. Benmarhnia T , et al
      . Effectiveness of pharmaceutical smoking cessation AIDS in a nationally representative cohort of American smokers. JNCI: Journal of the National Cancer Institute 2018;110:581–7.doi:10.1093/jnci/djx240
      OpenUrl
    22. ↵
      2. Prochaska JJ ,
      3. Benowitz NL
      . Current advances in research in treatment and recovery: nicotine addiction. Sci Adv 2019;5:eaay9763. doi:10.1126/sciadv.aay9763 pmid:http://www.ncbi.nlm.nih.gov/pubmed/31663029
      OpenUrlFREE Full Text
    23. ↵
      2. Horth RZ ,
      3. Crouch B ,
      4. Horowitz BZ , et al
      . Notes from the Field: Acute Poisonings from a Synthetic Cannabinoid Sold as Cannabidiol - Utah, 2017-2018. MMWR Morb Mortal Wkly Rep 2018;67:587–8.doi:10.15585/mmwr.mm6720a5 pmid:http://www.ncbi.nlm.nih.gov/pubmed/29795081
      OpenUrlPubMed
    24. ↵
      2. Ayers JW ,
      3. Caputi TL ,
      4. Leas EC
      . The need for federal regulation of marijuana marketing. JAMA 2019;321:2163.doi:10.1001/jama.2019.4432 pmid:http://www.ncbi.nlm.nih.gov/pubmed/31095243
      OpenUrlPubMed
    25. ↵
      2. Goel S ,
      3. Hofman JM ,
      4. Lahaie S , et al
      . Predicting consumer behavior with web search. Proc Natl Acad Sci U S A 2010;107:17486–90.doi:10.1073/pnas.1005962107 pmid:http://www.ncbi.nlm.nih.gov/pubmed/20876140
      OpenUrlAbstract/FREE Full Text
    26. ↵
      2. Ayers JW ,
      3. Althouse BM
      . "Tips From Former Smokers" Can Benefit From Considering All Available Data: Reply to McAfee et al. Am J Prev Med 2015;49:e133–4.doi:10.1016/j.amepre.2015.08.005 pmid:http://www.ncbi.nlm.nih.gov/pubmed/26456875
      OpenUrlPubMed
    27. ↵
      2. Wagener TL ,
      3. Siegel M ,
      4. Borrelli B
      . Electronic cigarettes: achieving a balanced perspective. Addiction 2012;107:1545–8.doi:10.1111/j.1360-0443.2012.03826.x pmid:http://www.ncbi.nlm.nih.gov/pubmed/22471757
      OpenUrlCrossRefPubMedWeb of Science
    28. ↵
      2. Leventhal AM ,
      3. Strong DR ,
      4. Kirkpatrick MG , et al
      . Association of electronic cigarette use with initiation of combustible tobacco product smoking in early adolescence. JAMA 2015;314:700–7.doi:10.1001/jama.2015.8950 pmid:http://www.ncbi.nlm.nih.gov/pubmed/26284721
      OpenUrlCrossRefPubMed
    29. ↵
      2. Grana R ,
      3. Benowitz N ,
      4. Glantz SA
      . E-Cigarettes: a scientific review. Circulation 2014;129:1972–86.doi:10.1161/CIRCULATIONAHA.114.007667 pmid:http://www.ncbi.nlm.nih.gov/pubmed/24821826
      OpenUrlFREE Full Text
    30. ↵
      2. Hammond D
      . Outbreak of pulmonary diseases linked to vaping. BMJ 2019;366:l5445.doi:10.1136/bmj.l5445 pmid:http://www.ncbi.nlm.nih.gov/pubmed/31506254
      OpenUrlFREE Full Text

    Footnotes

    • Twitter @TheodoreCaputi

    • Contributors All authors contributed to all aspects of the study.

    • Funding ALN acknowledges salary support from grant T32DA023356 from the National Institute of Drug Abuse. S-HZ acknowledges support from the California Department of Public Health.

    • Competing interests JA, JEC and MD are co-creators of Tobacco Watcher (www.tobaccowatcher.org). S-HZ is the founder of the California Smoker’s Helpline. JA and MD own equity in a company that previously had contracts with the California Smoker’s Helpline in the past 5 years. EL and ALN have been paid data science advisors to Tobacco Watcher in the past 5 years.

    • Provenance and peer review Not commissioned; externally peer reviewed.