Confirmatory factor analysis comparing incentivized experiments with self-report methods to elicit adolescent smoking and vaping social norms

www.nature.com/scientificreports OPEN Confirmatory factor analysis comparing incentivized experiments with self‑report methods to elicit adolescent smoking and vaping social norms Jennifer M. Murray1*, Erik O. Kimbrough2, Erin L. Krupka3, Abhijit Ramalingam4, Rajnish Kumar5, Joanna McHugh Power6, Sharon Sanchez‑Franco7, Olga L. Sarmiento7, Frank Kee8,9 & Ruth F. Hunter1,9* Many adolescent smoking prevention programmes target social norms, typically evaluated with selfreport, susceptible to social desirability bias. An alternative approach with little application in public health are experimental norms elicitation methods. Using the Mechanisms of Networks and Norms Influence on Smoking in Schools (MECHANISMS) study baseline data, from 12–13 year old school pupils (n = 1656) in Northern Ireland and Bogotá (Colombia), we compare two methods of measuring injunctive and descriptive smoking and vaping norms: (1) incentivized experiments, using monetary payments to elicit norms; (2) self-report scales. Confirmatory factor analysis (CFA) examined whether the methods measured the same construct. Paths from exposures (country, sex, personality) to social norms, and associations of norms with (self-reported and objectively measured) smoking behavior/ intentions were inspected in another structural model. Second-order CFA showed that latent variables representing experimental and survey norms measurements were measuring the same underlying construct of anti-smoking/vaping norms (Comparative Fit Index = 0.958, Tucker Lewis Index = 0.951, Root Mean Square Error of Approximation = 0.030, Standardized Root Mean Square Residual = 0.034). Adding covariates into a structural model showed significant paths from country to norms (secondorder anti-smoking/vaping norms latent variable: standardized factor loading [β] = 0.30, standard error [SE] = 0.09, p < 0.001), and associations of norms with self-reported anti-smoking behavior (β = 0.40, SE = 0.04, p < 0.001), self-reported anti-smoking intentions (β = 0.42, SE = 0.06, p < 0.001), and objectively measured smoking behavior (β = − 0.20, SE = 0.06, p = 0.001). This paper offers evidence for the construct validity of behavioral economic methods of eliciting adolescent smoking and vaping norms. These methods seem to index the same underlying phenomena as commonly-used self-report scales. Globally, tobacco smoking is still the most important preventable risk factor for chronic disease1. Smokers usually start during adolescence when the influence of social norms on behavior is most apparent2. Early prevention is 1 Centre for Public Health, Queen’s University Belfast, Institute of Clinical Sciences, Block B, Royal Victoria Hospital, Grosvenor Road, Belfast BT12 6BA, UK. 2Smith Institute for Political Economy and Philosophy, Chapman University, One University Drive, Orange, CA 92866, USA. 3School of Information, University of Michigan, 4322 North Quad, 105 S. State St., Ann Arbor, MI 48109‑1285, USA. 4Department of Economics, Appalachian State University, 416 Howard Street, ASU Box 32051, Boone, NC 28608, USA. 5Queen’s Management School, Queen’s University Belfast, Riddel Hall, 185 Stranmillis Road, Belfast BT9 5EE, UK. 6Department of Psychology, Maynooth University, Maynooth, Co. Kildare, Ireland. 7School of Medicine, University of the Andes, Carrera 1 No 18 A – 10, Bloque Q Piso 8, 57 Bogotá, Colombia. 8Centre for Public Health, Queen’s University Belfast, Institute of Clinical Sciences, Block A, Royal Victoria Hospital, Grosvenor Road, Belfast BT12 6BA, UK. 9These authors jointly supervised this work: Frank Kee and Ruth F. Hunter. *email: ; Scientific Reports | (2020) 10:15818 | https://doi.org/10.1038/s41598-020-72784-z 1 Vol.:(0123456789) www.nature.com/scientificreports/ critical because young smokers can develop serious chronic health problems and are more sensitive to nicotine addiction3. With the introduction of e-cigarettes into the market in the mid-2000s, and as a result of large-scale marketing, e-cigarettes have gained popularity in all age groups, and particularly amongst a dolescents4–7. Whilst e-cigarettes are seen as a potential cessation aid amongst adults, for adolescents they are more typically used for experimentation, similar to conventional cigarettes, are associated with willingness to smoke, and may act as a “gateway” to s moking4,8,9. Therefore, the current study examines social norms for smoking and vaping together. Adolescence is a time when young people are susceptible to social influence and many take their cues from the norms of friends, family, and most importantly, peers2. Therefore, many programmes aimed at smoking prevention are anchored in social norms approaches or overtly use peer influencers, with the majority targeting children at the outset of adolescence (around 12–13 years)10–12. The Mechanisms of Networks and Norms Influence on Smoking in Schools (MECHANISMS) study aims to prevent smoking amongst adolescents and to investigate the mechanisms through which social norms for smoking and vaping are established and transmitted through social networks in schools13. Social norms can be defined in terms of individuals’ beliefs regarding the actions and beliefs of others in a reference group, and an important distinction has been made between injunctive norms (doing what others think one should do) and descriptive norms (doing what others do)14. Survey-based measures of injunctive norms rely on participants’ self-reports regarding what others who are important to them (e.g. parents, friends, peers) think they “should (not)” do. Similarly, survey-based measures of descriptive norms ask respondents how frequently others who are important to them smoke. Such methods have the benefit of simplicity and clarity, but concerns about social desirability bias arise15 because a respondent may perceive that researchers do not approve of smoking, and may not wish to reveal that a parent smokes or would not disapprove of smoking. When considering the issue of social norms measurement for evaluating public health interventions, practical methods which can mitigate the impact of social desirability bias and contribute to understanding mechanisms, are r equired14. One potential method for eliciting social norms derives from game theory, a branch of economics that has developed well-defined mathematical models describing cooperation and competition. Using incentivized experimental approaches to elicit social norms has gained some traction in behavioral e conomics16, but there has been little evidence of transfer into public health. In behavioral economics research, these methods have been applied to explain behaviors such as reciprocity, co-operation, pro-sociality, or honouring agreements in the presence of a verbal p romise17,18. The MECHANISMS study applies incentivized experimental approaches to reduce social desirability bias when measuring social norms for adolescent smoking and vaping by asking respondents to gu (...truncated)