Assistant Professor of Social and Behavioral Sciences
Dr. Thomas Kirchner is a clinical-health psychologist and methodologist interested in the analysis and graphical representation of longitudinal and geographic data, including methodologies that link individual behavior to the real-time context in which it occurs. Dr. Kirchner’s research targets momentary influences on the maintenance of health-related behavior utilizing both field-based (ecological momentary assessment) and laboratory-based paradigms. These geographic information systems and analytical methods can then inform public health, research, and policy.
As the Director and Principal Investigator of the mHealth (mobile health) Lab, Dr. Kirchner uses GIS to understand health-related behavior and decision-making in real time (e.g., how people make decisions about what they eat and drink, the places they go to exercise in their neighborhoods, the amount of time they spend outdoors, and whether they smoke cigarettes and/or marijuana). In the Lab, students apply mHealth tools to explore geospatial systems, technology, research, and community advocacy. Students learn how to leverage the power of their cell phones to collect data about neighborhoods and experiences. In the POSSE (Point-of-sale Surveillance and Exposure) study, data is used to understand how tobacco-use behaviors are influenced in real-time by socio-contextual factors in real-world settings. Another initiative is exploring the link between marijuana and electronic vaporizers and the way legalization, decriminalization, and medicalization policies influence attitudes and decision-making about marijuana use in Colorado.
At CUSP - a public-private research center that observes, analyzes, and models cities to optimize outcomes, prototype new solutions, formalize new tools and processes, and develop new expertise/experts - Dr. Kirchner actively engages students and mentors projects.
MS, Clinical and Biological/Health Psychology, University of Pittsburgh, Pittsburgh, PAPhD, Clinical and Biological/Health Psychology, University of Pittsburgh, Pittsburgh, PA
Geographic Information Science (GIS)Geographically-explicit EMALongitudinal Data AnalysisUrban InformaticsUrban Science
Association of TAS2R38 haplotypes and menthol cigarette preference in an African American cohortRisso, D., Sainz, E., Gutierrez, J., Kirchner, T., Niaura, R., & Drayna, D.
Journal titleNicotine and Tobacco Research
Beyond blunts: reasons for cigarette and cigar use among African American young adult dual usersMead, E.L., Lindstrom Johnson, S., Siddiqui, J., Butler, J., Kirchner, T., & Feldman, R.H.
Journal titleAddiction Research and Theory
Background: African American young adults are at high risk for dual use of cigarettes and cigars. Limited work has explored and characterized the reasons for use in this population and their relative importance for initiation and current smoking of these products. Method: Reasons for cigarette and cigar use were systematically explored and categorized using a mixed methods participatory approach called concept mapping. A series of in-person group sessions were held with 30 African American young adult (ages 18–29) current smokers of both cigarettes and cigars in Prince George’s County, MD and Washington, DC. Participants brainstormed, sorted, rated, and interpreted their reasons for initiation and past 30-day use of cigarettes and cigars. A cluster map was generated using multi-dimensional scaling, and t-tests were used to explore differences in ratings by background characteristics. Results: Participants generated 64 reasons for smoking cigarettes and cigars, and categorized these reasons into six groups: emotions, urges, access, product characteristics, lifestyle, and outside pressure. Emotions and urges were the most important motivations for initiation and current smoking of both products. Product characteristics were significantly more important for cigar initiation and smoking than for cigarettes, and outside pressure was more important for current smoking of cigars than cigarettes. Ratings differed by gender, socioeconomic status, and smoking characteristics. Conclusions: Cigarette and cigar smoking have several overlapping motivations, but key differences were also found, most notably for product characteristics. The FDA’s regulation of cigars and cigarettes should focus on addressing key characteristics appealing to young adults to curb dual use.
Indicators of dependence for different types of tobacco product users: Descriptive findings from Wave 1 (2013–2014) of the Population Assessment of Tobacco and Health (PATH) studyStrong, D.R., Pearson, J., Ehlke, S., Kirchner, T., Abrams, D., Taylor, K., … Niaura, R.
Journal titleDrug and Alcohol Dependence
Background and aims With no established standard for assessing tobacco dependence (TD) across tobacco products in surveys, the Population Assessment of Tobacco and Health (PATH) Study provides a unique platform for examining the psychometric properties and validity of multiple indicators of tobacco dependence across a range of tobacco products. Participants A U.S. nationally representative sample from the 32,320 adult Wave 1 interviews with analyses focused on 14,287 respondents who were current established users of tobacco products. Findings This analysis confirms a single primary latent construct underlying responses to TD indicators for cigarettes, e-cigarettes, cigars, hookah, and smokeless tobacco products. Mutually exclusive past year tobacco-user groups included: cigarette only (n = 8689), e-cigarette only (n = 437), cigar only (traditional, cigarillo, or filtered) (n = 706), hookah only (n = 461), smokeless tobacco only (n = 971), cigarette plus e-cigarette (n = 709), and multiple tobacco product users (n = 2314). Differential Item Functioning (DIF) analyses supported use of 16 of the 24 examined TD indicators for comparisons across tobacco users. With cigarette users as a reference (mean = 0.0, SD = 1.0), we observed a range of TD with hookah (mean = −1.71) and cigar (mean = −1.92) only users being the lowest, and cigarette plus e-cigarette product users being the highest (mean = 0.35). Regression models including sociodemographic factors supported concurrent validity with increased product use frequency and TD among cigarette-only (p < 0.001), e-cigarette only (p < 0.002), cigar (p < 0.001), hookah only (p < 0.001), and smokeless tobacco users (p < 0.001). Conclusion The PATH Study Adult Wave 1 Questionnaire provided psychometrically valid measures of TD that enables future regulatory investigations of nicotine dependence across tobacco products.
A randomized trial comparing the effect of nicotine versus placebo electronic cigarettes on smoking reduction among young adult smokersTseng, T.Y., Ostroff, J.S., Campo, A., Gerard, M., Kirchner, T., Rotrosen, J., & Shelley, D.
Journal titleNicotine and Tobacco Research
Introduction: Electronic cigarette (EC) use is growing dramatically with use highest among young adults and current smokers. One of the most common reasons for using ECs is interest in quitting or reducing cigarettes per day (CPD); however there are few randomized controlled trials (RCT) on the effect of ECs on smoking abstinence and reduction. Methods: We conducted a two-arm; double-blind RCT. Subjects were randomized to receive 3-weeks of either disposable 4.5% nicotine EC (intervention) or placebo EC. The primary outcome was self-reported reduction of at least 50% in the number of CPDs smoked at week 3 (end of treatment) compared to baseline. Study subjects (n = 99) were young adult (21-35), current smokers (smoked ≥ 10 CPDs) living in NYC. Results: Compared with baseline, a significant reduction in CPDs was observed at both study time periods (1 and 3 weeks) for intervention (P < .001) and placebo (P < .001) groups. Between-group analyses showed significantly fewer CPDs in the intervention group compared to the placebo group at week 3 (P = .03), but not at any other follow-up periods. The logistic regression analysis showed that using a greater number of ECs, treatment condition and higher baseline readiness to quit were significantly associated with achieving at least 50% reduction in CPDs at the end of treatment. Conclusion: A diverse young adult sample of current everyday smokers, who were not ready to quit, was able to reduce smoking with the help of ECs. Further study is needed to establish the role of both placebo and nicotine containing ECs in increasing both reduction and subsequent cessation. Implications: Despite the critical need for well-designed clinical trials on the effect of ECs on cessation and cigarette reduction, the majority of studies have been observational or noncomparative intervention designs. Only three RCTs studying ECs as a cessation or reduction intervention have been published, and none were conducted in the United States. The current study adds knowledge to current literature on the feasibility of using ECs to aid smoking reduction among young smokers in US urban populations.
American spirit pack descriptors and perceptions of harm: A crowdsourced comparison of modified packsPearson, J.L., Richardson, A., Feirman, S.P., Villanti, A.C., Cantrell, J., Cohn, A., … Kirchner, T.
Journal titleNicotine and Tobacco Research
Introduction: In 2015, the Food and Drug Administration issued warnings to three tobacco manufacturers who label their cigarettes as "additive-free" and/or "natural" on the grounds that they make unauthorized reduced risk claims. The goal of this study was to examine US adults' perceptions of three American Spirit (AS) pack descriptors ("Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown Tobacco") to assess if they communicate reduced risk. Methods: In September 2012, three cross-sectional surveys were posted on Amazon Mechanical Turk. Adult participants evaluated the relative harm of a Marlboro Red pack versus three different AS packs with the descriptors "Made with Organic Tobacco," "100% Additive-Free," or "100% US Grown Tobacco" (Survey 1; n = 461); a Marlboro Red pack versus these AS packs modified to exclude descriptors (Survey 2; n = 857); and unmodified versus modified AS pack images (Survey 3; n = 1001). Results: The majority of Survey 1 participants rated the unmodified AS packs as less harmful than the Marlboro Red pack; 35.4%-58.8% of Survey 2 participants also rated the modified (no claims) packs as less harmful than Marlboro Red. In these surveys, prior use of AS cigarettes was associated with reduced perceptions of risk (adjusted odds ratio [AOR] 1.59-2.40). "Made with Organic Tobacco" and "100% Additive-Free" were associated with reduced perceptions of risk when comparing the modified versus the unmodified AS packs (Survey 3). Conclusions: Data suggest that these AS pack descriptors communicate reduced harm messages to consumers. Findings have implications for regulatory actions related to product labeling and packaging. Implications: These findings provide additional evidence that the "Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown" descriptors, as well as other aspects of the AS pack design, communicate reduced harm to non-, current, and former smokers. Additionally, they provide support for the importance of FDA's 2015 warning to Santa Fe Natural Tobacco Company on "100% Additive Free" as an unauthorized modified risk claim.
Spatio-temporal determinants of mental health and well-being: advances in geographically-explicit ecological momentary assessment (GEMA)Kirchner, T., & Shiffman, S.
Journal titleSocial Psychiatry and Psychiatric Epidemiology
Purpose: Overview of geographically explicit momentary assessment research, applied to the study of mental health and well-being, which allows for cross-validation, extension, and enrichment of research on place and health. Methods: Building on the historical foundations of both ecological momentary assessment and geographic momentary assessment research, this review explores their emerging synergy into a more generalized and powerful research framework. Results: Geographically explicit momentary assessment methods are rapidly advancing across a number of complimentary literatures that intersect but have not yet converged. Key contributions from these areas reveal tremendous potential for transdisciplinary and translational science. Conclusions: Mobile communication devices are revolutionizing research on mental health and well-being by physically linking momentary experience sampling to objective measures of socio-ecological context in time and place. Methodological standards are not well-established and will be required for transdisciplinary collaboration and scientific inference moving forward.
The Moment Study: Protocol for a mixed method observational cohort study of the Alternative Nicotine Delivery Systems (ANDS) initiation process among adult cigarette smokersPearson, J.L., Smiley, S.L., Rubin, L.F., Anesetti-Rothermel, A., Elmasry, H., Davis, M., … Abrams, D.
Journal titleBMJ Open
Introduction: Alternative Nicotine Delivery Systems (ANDS) such as e-cigarettes are battery-powered devices that aerosolize nicotine and other substances to simulate smoking without using tobacco. Little is known about the ANDS initiation process among adult smokers. The aims of this research are threefold to: (1) examine how ANDS use affects cigarette use; (2) examine how the immediate environmental and psychosocial contexts of cigarette and ANDS use vary within - and between - participants in general and by menthol preference and race; and, (3) examine participants' 'lived experience' of the subjective perceptions, meaning, influences and utility of cigarette and ANDS use. Methods and analyses: This study's mixed method, 6-week longitudinal design will produce a detailed description of the ANDS initiation process among adult smokers (N=100). Qualitative and quantitative data collection will include 3 weeks of: (1) ecological momentary assessment of patterns of cigarette/ANDS use, satisfaction, mood and craving; (2) geospatial assessment of participants' environment, including indoor and outdoor cigarette/ANDS norms and rules; (3) in-depth interviews about the meaning and utility o cigarette smoking and ANDS use; and, (4) saliva cotinine and exhaled carbon monoxide (CO) biomarkers. A diverse sample will be recruited with an equal number of menthol and non-menthol cigarette smokers. As the primary independent variable, we will investigate how ANDS use affects cigarette consumption. We will also examine how smoking related and ANDS-related rules and norms surrounding product use influence cigarette and ANDS product use, and how the subjective effects of ANDS use affect ANDS perceptions, beliefs and use. Ethics and dissemination: This study was funded by the National Institute on Drug Abuse of the US National Institutes of Health (1R21DA036472), registered at ClinicalTrials.gov (NCT02261363), and approved by the Chesapeake IRB (Pro00008526). Findings will be disseminated to the scientific and lay community through presentations, reports and scientific publications.
Tobacco outlet density and converted versus native non-daily cigarette use in a national US sampleKirchner, T., Anesetti-Rothermel, A., Bennett, M., Gao, H., Carlos, H., Scheuermann, T.S., … Ahluwalia, J.S.
Journal titleTobacco Control
Objective Investigate whether non-daily smokers' (NDS) cigarette price and purchase preferences, recent cessation attempts, and current intentions to quit are associated with the density of the retail cigarette product landscape surrounding their residential address. Participants Cross-sectional assessment of N=904 converted NDS (CNDS). who previously smoked every day, and N=297 native NDS (NNDS) who only smoked non-daily, drawn from a national panel. Outcome measures Kernel density estimation was used to generate a nationwide probability surface of tobacco outlets linked to participants' residential ZIP code. Hierarchically nested log-linear models were compared to evaluate associations between outlet density, non-daily use patterns, price sensitivity and quit intentions. Results Overall, NDS in ZIP codes with greater outlet density were less likely than NDS in ZIP codes with lower outlet density to hold 6-month quit intentions when they also reported that price affected use patterns (G2=66.1, p
Tobacco retail outlet density and young adult tobacco initiationCantrell, J., Pearson, J.L., Anesetti-Rothermel, A., Xiao, H., Kirchner, T., & Vallone, D.
Journal titleNicotine and Tobacco Research
Background: A growing body of evidence indicates that the density of tobacco retail outlets around the home residence may influence tobacco use among youth and adults. The purpose of this study was to examine the impact of neighborhood tobacco retail outlet density on young adult initiation of different tobacco product types. Methods: Cross-sectional data from a 2013 nationally representative sample of young adults aged 18-34 was examined in relation to a 2012 geocoded listing of all outlets likely to sell tobacco in the United States. Separate multivariable logistic regression analyses examined associations between neighborhood outlet density and past 6 months first use of cigarettes, non-cigarette combustible products, and noncombustible products among adults aged 18-24 and 25-34. Results: Outlet density was significantly associated with recent initiation of cigarettes and other combustibles, but this impact varied for younger and older groups. Increased density was significantly associated with a higher likelihood of initiating cigarette use among adults aged 25-34 (OR = 3.75, 95% CI = 1.18, 11.90), and of initiating non-cigarette combustible use among 18-24 year olds (OR = 3.16, 95% CI = 1.03, 9.74). There was no impact of outlet density on recent noncombustible product initiation among either group. Conclusion: This study is the first to examine the impact of tobacco outlet density on young adult initiation of cigarettes and other tobacco products. Findings demonstrate that residential neighborhood outlet density is associated with recent initiation of combustible products and this effect varies by product type and age. The tobacco outlet environment may be a critical factor in promoting young adult tobacco use initiation.
Cigarette price variation around high schools: Evidence from Washington DCCantrell, J., Ganz, O., Anesetti-Rothermel, A., Harrell, P., Kreslake, J.M., Xiao, H., … Kirchner, T.
Journal titleHealth and Place
This study examines lowest cigarette prices in all tobacco retail outlets in Washington D.C. (. n=750) in relation to the type and number of high schools nearby, controlling for confounders. The lowest overall and Newport menthol prices were significantly lower at outlets near public non-charter and charter schools compared with outlets near private schools. Given higher smoking prevalence and more price-sensitive youth subgroups in U.S. public schools, exposure to low prices may contribute to tobacco-related health disparities in minority and low-income populations. Tobacco taxes combined with policies to minimize the increasing use of price as a marketing tool are critical.
Cue reactivity in converted and native intermittent smokersShiffman, S., Dunbar, M.S., Kirchner, T., Li, X., Tindle, H.A., Anderson, S.J., … Ferguson, S.G.
Journal titleNicotine and Tobacco Research
Introduction: Nondaily, or intermittent smokers (ITS), who constitute a substantial fraction of U.S. smokers, are thought to smoke in response to cues. Previous cue reactivity research showed no difference between ITS and daily smokers in response to cues. This report examines whether "converted" ITS (CITS) with a history of past daily smoking differ from "native" ITS (NITS) in craving and smoking in response to cues. Methods: A total of 146 CITS (who previously smoked daily for at least 6 months) and 73 NITS participated. Participants were exposed to 5 active cues (smoking, alcohol, negative affect, positive affect, and smoking prohibitions) and a control neutral cue, in separate sessions. Changes in craving were assessed pre-post cue exposure. Smoking behavior (smoking [y/n], smoking latency, number of cigarettes, number of puffs, and increase in carbon monoxide [CO]) was observed. Analyses contrasted response to each active cue compared to the neutral cue and controlled for order effects and for time since last cigarette, which differed between groups. Results: Regardless of cues, CITS reported higher craving and greater change in craving, were more likely to smoke, tended to progress faster to smoking, and showed greater increases in CO when they did smoke. NITS and CITS showed similar cue reactivity on most measures, though NITS took more puffs after viewing smoking cues (compared to neutral) than did CITS. Conclusions: Though CITS show some remnants of their history of daily smoking, CITS and NITS demonstrate similar cue reactivity, suggesting that they would not require different behavioral approaches to help them quit.
Electronic cigarette advertising at the point-of-sale: A gap in tobacco control researchGanz, O., Cantrell, J., Moon-Howard, J., Aidala, A., Kirchner, T., & Vallone, D.
Journal titleTobacco Control
Implementation of a Multimodal Mobile System for Point-of-Sale Surveillance: Lessons Learned From Case Studies in Washington, DC, and New York CityCantrell, J., Ganz, O., Ilakkuvan, V., Tacelosky, M., Kreslake, J., Moon-Howard, J., … Kirchner, T.
Journal titleJMIR Public Health and Surveillance
National Enforcement of the FSPTCA at Point-of-SaleKirchner, T., Villanti, A.C., Tacelosky, M., Anesetti-rothermel, A., Gao, H., Pearson, J., … Abrams, D.B.
Journal titleTobacco Regulatory Science
The impact of the tobacco retail outlet environment on adult cessation and differences by neighborhood povertyCantrell, J., Anesetti-Rothermel, A., Pearson, J.L., Xiao, H., Vallone, D., & Kirchner, T.
Aims: This study examined the impact of tobacco retail outlets on cessation outcomes over time among non-treatment-seeking smokers and assessed differences by neighborhood poverty and individual factors. Design: Observational longitudinal cohort study using geospatial data. We used generalized estimating equations to examine cessation outcomes in relation to the proximity and density of tobacco retail outlets near the home. Setting: Eight large Designated Media Areas across the United States. Participants: A total of 2377 baseline smokers followed over three waves from 2008 to 2010. Measurements: Outlet addresses were identified through North American Industry Classification System codes and proximity and density measures were constructed for each participant at each wave. Outcomes included past 30-day abstinence and pro-cessation attitudes. Findings: Smokers in high poverty census tracts living between 500m and 1.9km from an outlet were over two times more likely to be abstinent than those living fewer than 500m from an outlet (P
Tobacco retail outlet advertising practices and proximity to schools, parks and public housing affect Synar underage sales violations in Washington, DCKirchner, T., Villanti, A.C., Cantrell, J., Anesetti-Rothermel, A., Ganz, O., Conway, K.P., … Abrams, D.
Journal titleTobacco Control
Objective To examine the cross-sectional association between illicit sales of tobacco to minors, Washington DC tobacco outlet advertising practices, retail store type, the demographic make-up of the area surrounding each outlet, and the proximity of each outlet to high schools, recreational parks and public housing. Participants Seven hundred and fifty tobacco outlets in the DC area, n=347 of which were randomly selected for inspection by the Synar Inspection Program in 2009–2010. Main outcome measures The presence of tobacco advertisements on the interior and exterior of each outlet, and illicit tobacco sales to Synar Inspection Program youth volunteers. Results The presence of tobacco advertisements on the exterior of gas stations was much greater than on other retail store types (OR=6.68; 95% CI 4.05 to 11.01), as was the absence of any advertisements at bars or restaurants that sold tobacco (OR=0.33; 95% CI 0.22 to 0.52). Exterior tobacco advertisements were also more likely in predominantly African–American areas of the city (OR=3.11; 95% CI 2.28 to 4.25), and particularly likely on storefronts located closer to parks (OR=1.87; 95% CI 1.06 to 3.28). Illicit sales to minors were more common at gas stations (OR=3.01; 95% CI 1.5 to 6.3), outlets that displayed exterior tobacco advertisements closer to parks (OR=3.36; 95% CI 1.38 to 8.21), and outlets located closer to high schools in majority African– American block groups (OR=1.29; 95% CI 1.07 to 1.58). Conclusions Findings demonstrate that while illicit tobacco sales to minors are occurring at acceptably low rates by Synar standards, illicit sales vary considerably by retail store type, advertising approach and proximity to high schools, parks and African–American residential areas. Future work may help inform regulatory efforts to reduce youth access at the neighbourhood, city, state and national levels.
Cameras for Public Health Surveillance: A Methods Protocol for Crowdsourced Annotation of Point-of-Sale PhotographsIlakkuvan, V., Tacelosky, M., Ivey, K.C., Pearson, J.L., Cantrell, J., Vallone, D.M., … Kirchner, T.
Journal titleJMIR Research Protocols
Cantrell et al. RespondCantrell, J., Kreslake, J., Ganz, O., Pearson, J.L., Vallone, D.M., Anesetti-Rothermel, A., … Kirchner, T.
Journal titleAmerican Journal of Public Health
Crowdsourcing applications for public healthBrabham, D.C., Ribisl, K.M., Kirchner, T., & Bernhardt, J.M.
Journal titleAmerican Journal of Preventive Medicine
Crowdsourcing is an online, distributed, problem-solving, and production model that uses the collective intelligence of networked communities for specific purposes. Although its use has benefited many sectors of society, it has yet to be fully realized as a method for improving public health. This paper defines the core components of crowdsourcing and proposes a framework for understanding the potential utility of crowdsourcing in the domain of public health. Four discrete crowdsourcing approaches are described (knowledge discovery and management; distributed human intelligence tasking; broadcast search; and peer-vetted creative production types) and a number of potential applications for crowdsourcing for public health science and practice are enumerated.
Longitudinal human mobility and real-time access to a national density surface of retail outletsKirchner, T., Gao, H., Anesetti-Rothermel, A., Carlos, H., & House, B.
Journal titleACM Urban Computing
Nicotine dependence, "background" and cue-induced craving and smoking in the laboratoryDunbar, M.S., Shiffman, S., Kirchner, T., Tindle, H.A., & Scholl, S.M.
Journal titleDrug and Alcohol Dependence
Background: Nicotine dependence has been associated with higher "background" craving and smoking, independent of situational cues. Due in part to conceptual and methodological differences across past studies, the relationship between dependence and cue-reactivity (CR; e.g., cue-induced craving and smoking) remains unclear. Methods: 207 daily smokers completed six pictorial CR sessions (smoking, negative affect, positive affect, alcohol, smoking prohibitions, and neutral). Individuals rated craving before (background craving) and after cues, and could smoke following cue exposure. Session videos were coded to assess smoking. Participants completed four nicotine dependence measures. Regression models assessed the relationship of dependence to cue-independent (i.e., pre-cue) and cue-specific (i.e., pre-post cue change for each cue, relative to neutral) craving and smoking (likelihood of smoking, latency to smoke, puff count). Results: Dependence was associated with background craving and smoking, but did not predict change in craving across the entire sample for any cue. Among alcohol drinkers, dependence was associated with greater increases in craving following the alcohol cue. Only one dependence measure (Wisconsin Inventory of Smoking Dependence Motives) was consistently associated with smoking reactivity (higher likelihood of smoking, shorter latency to smoke, greater puff count) in response to cues. Conclusion: While related to cue-independent background craving and smoking, dependence is not strongly associated with laboratory cue-induced craving under conditions of minimal deprivation. Dependence measures that incorporate situational influences on smoking correlate with greater cue-provoked smoking. This may suggest independent roles for CR and traditional dependence as determinants of smoking, and highlights the importance of assessing behavioral CR outcomes.
Rapid grading of fundus photographs for diabetic retinopathy using crowdsourcingBrady, C.J., Villanti, A.C., Pearson, J.L., Kirchner, T., Gupta, O.P., & Shah, C.P.
Journal titleJournal of Medical Internet Research
Background: Screening for diabetic retinopathy is both effective and cost-effective, but rates of screening compliance remain suboptimal. As screening improves, new methods to deal with screening data may help reduce the human resource needs. Crowdsourcing has been used in many contexts to harness distributed human intelligence for the completion of small tasks including image categorization. Objective: Our goal was to develop and validate a novel method for fundus photograph grading. Methods: An interface for fundus photo classification was developed for the Amazon Mechanical Turk crowdsourcing platform. We posted 19 expert-graded images for grading by Turkers, with 10 repetitions per photo for an initial proof-of-concept (Phase I). Turkers were paid US $0.10 per image. In Phase II, one prototypical image from each of the four grading categories received 500 unique Turker interpretations. Fifty draws of 1-50 Turkers were then used to estimate the variance in accuracy derived from randomly drawn samples of increasing crowd size to determine the minimum number of Turkers needed to produce valid results. In Phase III, the interface was modified to attempt to improve Turker grading. Results: Across 230 grading instances in the normal versus abnormal arm of Phase I, 187 images (81.3%) were correctly classified by Turkers. Average time to grade each image was 25 seconds, including time to review training images. With the addition of grading categories, time to grade each image increased and percentage of images graded correctly decreased. In Phase II, area under the curve (AUC) of the receiver-operator characteristic (ROC) indicated that sensitivity and specificity were maximized after 7 graders for ratings of normal versus abnormal (AUC=0.98) but was significantly reduced (AUC=0.63) when Turkers were asked to specify the level of severity. With improvements to the interface in Phase III, correctly classified images by the mean Turker grade in four-category grading increased to a maximum of 52.6% (10/19 images) from 26.3% (5/19 images). Throughout all trials, 100% sensitivity for normal versus abnormal was maintained. Conclusions: With minimal training, the Amazon Mechanical Turk workforce can rapidly and correctly categorize fundus photos of diabetic patients as normal or abnormal, though further refinement of the methodology is needed to improve Turker ratings of the degree of retinopathy. Images were interpreted for a total cost of US $1.10 per eye. Crowdsourcing may offer a novel and inexpensive means to reduce the skilled grader burden and increase screening for diabetic retinopathy.
Cue reactivity in non-daily smokers: Effects on craving and on smoking behaviorShiffman, S., Dunbar, M.S., Kirchner, T., Li, X., Tindle, H.A., Anderson, S.J., … Ferguson, S.G.
Rationale: Non-daily, or intermittent smokers (ITS), are increasingly prevalent. Their smoking may be more situational than that of daily smokers (DS), and thus is hypothesized to be more influenced by cues. Objectives: To assess ITS' response to cues, and compare it to that of DS. Methods: Samples of 239 ITS and 207 DS (previously reported in Shiffman et al. 2012a) were studied in 2,586 laboratory cue-reactivity sessions. Craving (Questionnaire of Smoking Urges) and smoking (probability, latency, puff parameters, and carbon monoxide increases) in response to cues was assessed following exposure to neutral cues and cues related to smoking, alcohol, negative affect, positive affect, and smoking prohibitions. Mixed effects models, generalized estimating equations and random-effects survival analyses were used to assess response to cues and differences between DS and ITS. Results: ITS' craving increased following exposure to smoking and alcohol cues and decreased following positive affect cues, but cues had little effect on smoking behaviors. Cue reactivity was similar in ITS and DS. Among ITS, craving intensity predicted smoking probability, latency, and intensity, and the effects on latency were stronger among ITS than DS. Conclusions: Contrary to hypotheses, ITS were not more responsive to laboratory cues than DS. Results show that ITS do experience craving and craving increases that are then associated with smoking.
Ecological Momentary AssessmentKirchner, T., & Shiffman, S.
This chapter addresses application of ecological momentary assessment (EMA) to substance use research, outlining principles of EMA design and analysis, and illustrates them with examples. It considers the way technological innovations are facilitating the rapid evolution of EMA systems, and provides recommendations on current best practices. The chapter reviews data on methodological issues such as compliance and reactivity. EMA sampling design focuses on the way assessments of individual- and systems-level processes are distributed over time and space. EMA methods reveal substance use patterns not captured by questionnaires or retrospective data, and hold great promise for substance use research and treatment. As EMA methods are further developed and broadly applied, they offer even more detailed insight into substance use and abuse. Further, application of EMA approaches to on-the-spot intervention with substance users holds potential to revolutionize treatment delivery. This edition first published 2013
Geospatial exposure to point-of-sale tobacco: Real-time craving and smoking-cessation outcomesKirchner, T., Cantrell, J., Anesetti-Rothermel, A., Ganz, O., Vallone, D.M., & Abrams, D.
Journal titleAmerican Journal of Preventive Medicine
Background: Little is known about the factors that drive the association between point-of-sale marketing and behavior, because methods that directly link individual-level use outcomes to real-world point-of-sale exposure are only now beginning to be developed. Purpose: Daily outcomes during smoking cessation were examined as a function of both real-time geospatial exposure to point-of-sale tobacco (POST) and subjective craving to smoke. Methods: Continuous individual geospatial location data collected over the first month of a smoking-cessation attempt in 2010-2012 (N=475) were overlaid on a POST outlet geodatabase (N=1060). Participants' mobility data were used to quantify the number of times they came into contact with a POST outlet. Participants recorded real-time craving levels and smoking status via ecological momentary assessment (EMA) on cellular telephones. Results: The final data set spanned a total of 12,871 days of EMA and geospatial tracking. Lapsing was significantly more likely on days with any POST contact (OR=1.19, 95% CI=1.18, 1.20), and increasingly likely as the number of daily POST contacts increased (OR=1.07, 95% CI=1.06, 1.08). Overall, daily POST exposure was significantly associated with lapsing when craving was low (OR=1.22, 95% CI=1.20, 1.23); high levels of craving were more directly associated with lapse outcomes. Conclusions: These data shed light on the way mobility patterns drive a dynamic interaction between individuals and the POST environment, demonstrating that quantification of individuals' exposure to POST marketing can be used to identify previously unrecognized patterns of association among individual mobility, the built environment, and behavioral outcomes.