Neglected tropical diseases (NTDs) are a diverse group of 20 infectious diseases that affect more than 1 billion of the world's poorest people and cost developing economies billions of dollars every year.1 The complex nature of these diseases, as well as the weak political influence of the affected groups, previously resulted in a lack of attention and resources, and precipitated the use of the term “neglected.”2 Addressing these diseases together under the umbrella “NTDs” in 2003 has contributed to increased interest, research, funding, and implementation support to prevention and control efforts.3 Moreover, it led to formal recognition by the United Nations, and NTDs were included in the Sustainable Development Goals (SDGs) with the following targets: “By 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases” (SDG 3.3).4(p.223) The concomitant paradigm shift from vertical, disease-specific approaches towards an integrated approach resulted in five interconnected public health strategies for preventing and controlling NTDs, advocated by the World Health Organization: preventive chemotherapy; innovative and intensified case management; vector ecology and management; safe water, sanitation, and hygiene; and veterinary public health.5
Although preventive chemotherapy (i.e. low-cost mass drug administration without individual diagnosis) is at the core of NTD programs,6 other approaches not utilizing therapeutics (e.g. surveillance systems) should be considered equally important.7 Mass drug administration relies on strong health care infrastructure, which is not always available, especially in low- and middle-income countries,8 and additionally, high therapeutic pressure could result in drug resistance and eventually lead to unsustainable control.9 Therefore, a holistic approach to combating NTDs in the long term is widely recommended, shifting away from the focus on medical approaches to an all-inclusive and multisectoral approach that involves a broad range of stakeholders.10 The BEST (behavior, environment, social inclusion, and treatment) framework was developed by the NTDs NGO Network to allow for a comprehensive approach towards NTDs.11 Although all four aspects are equally important, and contrary to evidence suggesting that community-based and integrated approaches are far more effective in achieving sustained control,12 most research and funding at present is still devoted to therapeutic treatment only.13 Moreover, community-based and integrated interventions tend to be more resource-demanding, and despite the evidence of NTD interventions being “one of the best health investments” according to Molyneux et al.,8(p.312) there is an underinvestment of funds, reflecting the continuing inequality in global health financing. Therefore, the need for effective, low-cost community and behavioral interventions targeting the NTDs increases.
Recent studies in handwashing behavior for NTD prevention and control present evidence for “nudging” or similar alternative approaches as effective and low-cost behavior change strategies.14 The purpose of nudging is to nudge, or subtly direct, people towards positive behavioral choices. It reinforces the idea of choice, but at the same time subtly steers people to make certain favorable decisions for themselves or others. Favorable decisions or favorable behavior relating to preventive medicine should have a positive health outcome for the people or patients involved.15 Nudging is grounded in behavioral economics, which is a discipline combining both economics and psychology, and aims to provide an alternative perspective to the assumption that behavior is governed by rational decision-making, as exemplified in traditional economics.16 The theory acknowledges the limitations inherent to human decision-making, and identifies the cause as our “bounded rationality” (e.g. the limitation of human rationality by several factors such as cognitive and emotional biases, peer and time pressure).17 Thaler and Sunstein address these limitations by presenting the nudge as a behavioral strategy in their book Nudge: Improving Decisions about Health, Wealth and Happiness,18 making the insights from behavioral economics more applicable and accessible. From that point on, nudging strategies have become more widely known among the general public, and have been incorporated into public policy.19 According to the authors, who do not offer a definitive definition but merely suggest an interpretation of the term, a nudge is “…any aspect of the choice architecture that alters people's behavior in a predictable way without forbidding any options or significantly changing their economic incentives. To count as a mere nudge, the intervention must be easy and cheap to avoid.”18(p.6)
Nudges should be conceptualized as distinct from regulations (i.e. mandatory guidelines that do not present a choice to the public) or from significant economic incentives (e.g. taxes), hence the attraction to public policy makers. Nonetheless, a nudge assumes individuals are not rational actors, capable of making more favorable decisions, which defers responsibility to those in a position of leadership.20 This paternalistic view has become an issue of critique, since an individual's autonomy of choice is being questioned.21 However, Thaler and Sunstein use the term “libertarian paternalism,” which underlines this freedom of choice, while attributing some responsibility to the person or group nudging the individual.22 Nevertheless, they acknowledge the influencing role of the “nudger,” but the guiding ethos should result in a benefit for the “nudgee.”23
The concept of influencing people's decision-making via environmental changes in order to support or achieve behavioral changes, and without depriving them of choice, has been in existence for decades.24 However, it is only recently that it has been attributed to a certain discipline (i.e. behavioral economics), with a certain conceptual label (i.e. nudging), and to a specified goal (i.e. for societal good). For the past 10 years, a growing body of research has focused on these strategies, many of which are attributed to certain lifestyle choices such as healthy eating25 and physical activity,26 and with a primary goal to curb the current epidemic of non-communicable diseases. To some extent, preventive and control practices targeting NTDs rely on certain lifestyle choices, and therefore may potentially benefit from a modest nudge towards a more favorable direction.
To our knowledge, studies focusing on nudging strategies for infectious disease control, and more specifically prevention and control of NTDs, have not been synthesized, which presents an opportunity for a scoping review. This scoping review will synthesize the available evidence on various types of nudge strategies in the prevention and control of NTDs. It will aim to give an overview of studies in the growing field of nudge theory, with a particular focus on behavioral practices suitable for combatting NTDs. The outcomes of this scoping review will identify and map knowledge gaps for researchers, and present new strategies for altering behavior in NTD prevention and control.
A preliminary search for systematic and scoping reviews on similar topics was conducted on December 16, 2019. The following databases did not provide evidence for any existing studies on nudging strategies: JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews, and Epistemonikos.
- i) What types of nudge strategies have been used to influence behavior-based and individual prevention and control practices of NTDs in low- and middle-income countries?
- ii) Which specific infection prevention and control behaviors were targeted through these nudge strategies? Was this disease/transmission focused?
- iii) What setting/population was the nudge strategy targeting? Which underlying theory/research informed the nudge strategy?
- iv) How was the nudge strategy applied? What behavioral outcome measures were reported in the studies?
The scoping review will include all populations exposed to a nudge strategy related to behavioral practices for NTD prevention and control in low- and middle-income countries.
All nudge strategies will be reviewed, regardless of whether they include the explicit label of a “nudge” or not. To count as a nudge, the authors will consider the description by Thaler and Sunstein “…any aspect of the choice architecture that alters people's behavior in a predictable way without forbidding any options or significantly changing their economic incentives. To count as a mere nudge, the intervention must be easy and cheap to avoid.”18(p.6) This review aims to capture all behavioral practices leading to NTD prevention and control, and not merely aimed at targeting NTDs specifically. Therefore, strategies aimed at changing individual health-specific behaviors (e.g. handwashing behavior), although not focused on preventing or controlling a type or group of NTDs, will also be included in the review. Articles focused on prevention of NCDs, or other types of health-related behaviors not relevant to NTD prevention and control, or using another type of strategy that does not qualify as a nudge, will be excluded.
All contexts in low- and middle-income countries will be considered eligible and will include, but not be restricted to, public spaces, health care facilities, school settings, and indoor/outdoor community facilities
Types of sources
Due to the nature of this review, no restrictions will be placed on the type of evidence. All study designs will be included. However, to be eligible for inclusion, the nudge strategy or intervention must be described in full. Therefore, reviews, opinion papers, and letters will be excluded if they do not present a full description of a behavior strategy.
The authors will utilize the JBI methodology for scoping reviews. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) checklist27 will be used as a reporting guideline, while the JBI Reviewer's Manual28 will be used for methodological guidance. The authors do not aim to systematically assess the quality of the available studies, nor are they concerned with the effectiveness of the nudge strategies, which is required for systematic literature reviews. The authors will focus on i) synthesizing and mapping existing studies on behavioral practices suitable for prevention and control of NTDs in low- and middle-income countries, and ii) identifying gaps in the literature that could contribute to future research in NTD prevention and control.
Recommendations for scoping reviews suggest that the search strategy be as inclusive and comprehensive as possible. Because the term “nudging” has only recently been established and operationalized, studies with a similar focus may be excluded from the review due to different terms used to describe the nudging technique. The challenge of missing potentially eligible studies due to the lack of consistent labeling of the term “nudge” has been reported previously.29 Therefore, the authors will consider including relevant and alternative terms of nudging, as well as subcategories of the technique. To identify these terms, the authors will use a similar approach to Möllenkamp et al.29; by identifying existing categorizations of nudges, as well as the most important nudges (according to Sunstein30), the authors will be able to extract important sub-categories and terms for nudging. These terms will be included in the search in combination with the umbrella term “behavioral intervention.”
The authors will conduct a comprehensive search in the following databases: MEDLINE, PsycINFO, Embase (Ovid), Web of Science Core Collection, CINAHL, ERIC, and EconLit (EBSCO), as well as registered trials and reviews in CENTRAL and PROSPERO to identify in-progress or unpublished studies related to the scope of the review. Moreover, references of included studies will be screened, as well as a citation tracking in Web of Science and Google Scholar. In addition, websites of governmental nudge units will be searched for behavioral trials, such as the Behavioral Insights Team (UK), the Social and Behavioral Science Team (US), the Behavioral Economics Team (AU), the Mistery of Manpower (SG), and iNudgeyou (DK), as well as The European Nudging network.
The search algorithm will consist of two combined strings developed with search terms such as keywords (in title and abstracts) and MeSH (Medical Subject Headings). The first string will consist of terms related to nudge strategies, the second string will include terms related to preventive and control practices for NTDs. The development of the search strategy will take place in collaboration with a librarian, who is also a member of the primary research team for this scoping review. A proposed final search strategy in MEDLINE is presented in Appendix I. A preliminary search conducted on April 30, 2020, retrieved 318 records and is presented in Appendix II.
Review articles will be excluded; however, references in review articles will be screened for identification of missed studies, which will be subsequently added to the included studies. Studies must be full-text papers, peer-reviewed articles or gray literature published in English or Spanish. Conference proceedings, as well as editorial letters and comments, will be excluded from further analysis.
All literature will be identified and collected by one review author (FVV) and downloaded to EndNote X9 (Clarivate Analytics, PA, USA), and duplicates removed. The titles will be screened by one reviewer only, due to an expected large number of results. Non-eligible studies will be excluded from the analysis. Two reviewers (SB and FVV) will screen the abstracts independently from each other. Eligible studies will be selected through a questionnaire that specifies the inclusion criteria. Finally, full-text articles will be reviewed if eligibility is uncertain, and any disagreements in judgment will be resolved by discussion to reach a consensus, or if this fails, a third review author (JL) will be included until consensus is reached.
Data extraction and presentation
All papers selected for inclusion will be subjected to a data extraction procedure designed by one review author (FVV) and agreed upon by the other review authors. The a priori developed extraction form will be pilot tested to minimize misinterpretation and to ensure all relevant data are included in the analysis. Given the diversity of studies, the piloting will be conducted among a sample comprising each major study type (e.g. qualitative, experimental, observational). Ultimately, the data extraction procedure will be conducted by one review author (FVV), while a second reviewer (SB) will validate 25% of the extracted information. In case of disagreement, a third reviewer (JL) will be consulted. The extraction form will include the following predefined categories: authors; journal; year of publication; type of publication; geographical area of the intervention; targeted population; setting of the intervention; domain of preventive practices (e.g. hygiene, vector control); targeted behavior description (e.g. handwashing); protection of self or others (i.e. whether the behavior is focused on protecting oneself such as through handwashing, or other behaviors such as vector control in the community); targeted NTD, if specified (e.g. dengue); transmission of the NTD (e.g. soil-transmitted helminths); nudge strategy characteristics; underlying informative theory; and intervention results. Moreover, the nudge strategies will be categorized using the taxonomy developed by Münscher et al.31: decision information (translation of information, visibility, and social norm); decision structure (defaults, option-related effort, composition, and consequences); and decision assistance (reminders, commitment). Given that nudges raise ethical concerns, the interventions will be evaluated based on the ethical criteria designed by Engelen.32 In order to map and compare the included studies, the extracted data will be synthesized and presented in a table, as well as graphic and other conceptual presentation styles more suitable for visualization of the data.
The scoping review will be conducted as part of the MY-SCOOL project, funded by the Research Council of Norway, GLOBVAC 285188. The funders provided financial support to the research team for implementing the research, but had no involvement in any kind in developing the content.
Appendix I: Proposed final search strategy
Appendix II: Preliminary search strategy
MEDLINE (Ovid). Date searched: April 30, 2020.
1. World Health Organization. Integrating neglected tropical diseases in global health and development, Fourth WHO report on neglected tropical diseases [Internet]. 2017 [cited Jan 2020]. Available from: https://apps.who.int/iris/bitstream/handle/10665/255011/9789241565448-eng.pdf
2. Matilla F, Velleman Y, Harrison W, Nevel M. Animal influence on water, sanitation and hygiene measures for zoonosis control at the household level: a systematic literature review. PLoS Negl Trop Dis
2018; 12 (7):e0006619.
3. World Health Organization. Intensified control of neglected diseases: report of an international workshop, Berlin, Germany, 10–12 December 2003 [Internet]. 2004 [cited Jan 2020]. Available from: https://apps.who.int/iris/bitstream/handle/10665/68529/WHO_CDS_CPE_CEE_2004.45.pdf
4. Engels D. Neglected tropical diseases in the Sustainable Development Goals. Lancet
2016; 387 (10015):223–224.
5. World Health Organization. Accelerating work to overcome the global impact of neglected tropical diseases: a roadmap for implementation [Internet]. 2012 [cited Jan 2020]. Available from: https://www.who.int/neglected_diseases/NTD_RoadMap_2012_Fullversion.pdf
6. Webster JP, Molyneux DH, Hotez PJ, Fenwick A. The contribution of mass drug administration to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci
2014; 369 (1645):20130434.
7. Ortu G, Williams O. Neglected tropical diseases: exploring long term practical approaches to achieve sustainable disease elimination and beyond. Infect Dis Poverty
2017; 6 (1):147.
8. Molyneux DH, Savioli L, Engels D. Neglected tropical diseases: progress towards addressing the chronic pandemic. Lancet
2017; 389 (10066):312–325.
9. Vercruysse J, Albonico M, Behnke JM, Kotze AC, Prichard RK, McCarthy JS, et al. Is anthelmintic resistance a concern for the control of human soil-transmitted helminths? Int J Parasitol Drugs Drug Resist
2011; 1 (1):14–27.
10. Freeman MC, Ogden S, Jacobson J, Abbott D, Addiss DG, Amnie AG, et al. Integration of water, sanitation, and hygiene for the prevention and control of neglected tropical diseases: a rationale for inter-sectoral collaboration. PLoS Negl Trop Dis
2013; 7 (9):e2439.
11. Neglected Tropical Diseases NGO Network. The BEST Framework: a comprehensive approach towards Neglected Tropical Diseases [Internet]. [cited Jan 2020]. Available from: https://www.ntd-ngonetwork.org/the-best-framework
12. Das JK, Salam RA, Arshad A, Maredia H, Bhutta ZA. Community based interventions for the prevention and control of non-helmintic NTD. Infect Dis Poverty
13. Kappagoda S, Ioannidis JP. Prevention and control of neglected tropical diseases: overview of randomized trials, systematic reviews and meta-analyses. Bull World Health Org
2014; 92 (5):356–366.
14. Dreibelbis R, Kroeger A, Hossain K, Venkatesh M, Ram PK. Behavior change without behavior change communication: nudging handwashing among primary school students in Bangladesh. Int J Environ Res Public Health
2016; 13 (1):14.
15. Fridman I, Hart JL, Yadav KN, Higgins ET. Perspectives on using decision-making nudges in physician-patient communications. PLoS One
2018; 13 (9):e0202874.
16. Camerer C. Behavioral economics: reunifying psychology and economics. Proc Natl Acad Sci U S A
1999; 96 (19):10575–10577.
17. Kahneman D. A perspective on judgment and choice: mapping bounded rationality. Am Psychol
2003; 58 (9):697–720.
18. Thaler RH, Sunstein CR. Nudge: improving decisions about health, wealth, and happiness. New Haven: Yale University Press; 2008.
19. Halpern D, Sanders M. Nudging by government: progress, impact, and lessons learned. Behav Sci Policy
2016; 2 (2):52–65.
20. Raihani NJ. Nudge politics: efficacy and ethics. Front Psychol
21. Epstein RA. The dangerous allure of libertarian paternalism. Rev Behav Econ
2018; 5 (3–4):389–416.
22. Thaler RH, Sunstein C. Libertarian paternalism. Am Econ Rev
2003; 93 (2):175–179.
23. Barton A, Grüne-Yanoff T. From libertarian paternalism to nudging—and beyond. Rev Philos Psychol
2015; 6 (3):341–359.
24. Vallgårda S. Nudge—a new and better way to improve health? Health Policy
2012; 104 (2):200–203.
25. Arno A, Thomas S. The efficacy of nudge theory strategies in influencing adult dietary behaviour: a systematic review and meta-analysis. BMC Public Health
2016; 16 (1):676.
26. Forberger S, Reisch L, Kampfmann T, Zeeb H. Nudging to move: a scoping review of the use of choice architecture interventions to promote physical activity in the general population. Int J Behav Nutr Phys Act
2019; 16 (1):77.
27. Tricco AC, Lillie E, Zarin W, O’Brien KK, Colquhoun H, Levac D, et al. PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med
2018; 169 (7):467–473.
28. Peters MDJ, Godfrey C, McInerney P, Munn Z, Tricco AC, Khalil H. Chapter 11: Scoping Reviews. In: Aromataris E, Munn Z, editors. JBI Reviewer's Manual [Internet]. Adelaide: JBI, 2020 [cited Jan 2020]. Available from: https://reviewersmanual.joannabriggs.org/
29. Dolan P, Hallsworth M, Halpern D, King D, Metcalfe R, Vlaev I. Influencing behaviour: the mindspace way. J Econ Psychol
2012; 33 (1):264–277.
30. Sunstein CR. Nudging: a very short guide. J Consum Policy
2014; 37 (4):583–588.
31. Münscher R, Vetter M, Scheuerle T. A review and taxonomy of choice architecture techniques. J Behav Decis Mak
2016; 29 (5):511–524.
32. Engelen B. Ethical criteria for health-promoting nudges: a case-by-case analysis. Am J Bioeth
2019; 19 (5):48–59.