1. Introduction
Crowdsourcing was first definitized by Jeff Howe in 2006, to represent the act of organizations outsourcing their tasks to an undefined and large group of people [
1]. Brabham described crowdsourcing as an online, distributed problem-solving and production model [
2]. Crowdsourcing allows access to a large pool of public volunteers, saves time in collecting data, reduces costs, and accelerates the speed of innovation [
3,
4]. With increasing globalization and continuing internationalization trends, the flattening effect of Globalization 3.0 has created an environment that encourages the growth of crowdsourcing [
5]. Crowdsourcing can extend the innovation activities of enterprises to an infinite and vast network space—it also explores, utilizes, and integrates the innovation resources of the whole society and the wisdom of the society through the Internet [
6,
7,
8,
9]. From the fields of innovative design to hygiene, positioning services, and new product development, crowdsourcing quietly subverts business models and traditional social structures [
10,
11].
The Internet has greatly reduced the cost of information transfer and the boundaries of participating activities. In this context, the concept of health 2.0 has been proposed with the practice of crowdsourcing in the field of health communication [
12]. Every health sector can benefit from a crowd of tasks that can facilitate research [
3]. There is no doubt that crowdsourcing creates a great opportunity in health, hygiene, and medical research. As appointed by Swan, crowdsourcing health studies are the union of three contemporary tendencies, namely “citizen science,” crowdsourcing, and Medicine 2.0 [
13]. Medicine 2.0 or Health 2.0 announces individuals actively participating in their health care, especially utilizing Web 2.0 technology [
13]. Like Internet 2.0, Terry argues that Health 2.0 promotes self-creation, sharing, community concepts, and user self-empowerment, all of which coincide with the aim of crowdsourcing [
14].
In recent years, the involvement of crowdsourcing in hygiene and health has been of scholarly interest. Perrine et al. summarized that different types of crowdsourcing projects can be adopted in health promotion, research, and care [
3]. Maged et al. pointed out that, leveraging the power of crowdsourcing, the citizen can easily engage in public and environmental health surveillance in order to provide crowdsourced maps through social web and smartphones [
15]. Brabham argued that crowdsourcing offers the opportunity to improve health actions via public involvement online [
16]. Wazny conducted an overview analysis to examine how crowdsourcing has been used in global health, including diagnosis, surveillance, nutrition, public health and the environment, education, genetics, psychology, and general medicine [
17]. In summary, crowdsourcing brings together the best of scientists, the public, and online communities. Further, it offers an effective approach to obtain data, track health, and monitor records, etc. Hence, crowdsourcing creates a huge opportunity for researchers to conduct research on health promotion, health monitoring, health maintenance, and behavioral surveying.
With 4.02 billion Internet users and 5.14 billion unique mobile subscribers [
18], online platforms and mobile apps for crowdsourcing have been developed to improve public health [
19], particularly in tracking diet and exercise, aiding smokers’ cessation, preventing binge drinking, and disseminating health communication, etc. Public health commits to improving the quality of life by preventing and treating diseases and, nowadays, many subfields of public health have drawn scholars’ attention, such as community health, behavioral health, mental health, occupational safety, gender issues in health, and sexual health [
20,
21,
22]. Harrison C et al. used crowdsourcing to predict unreported outbreaks and foodborne illnesses based on the business review website Yelp [
23]. Wilson J et al. conducted an online survey of US adults about their perceptions of chiropractors to test the feasibility of using the Amazon Mechanical Turk (MTurk) [
24]. Crowdsourcing contests provide an opportunity for online citizens to participate in public engagement. For example, a competition was organized to draw public attention to heart disease by mapping the locations of automated external defibrillators [
25]. Another contest experiment was that Joseph D et al. asked participants to design and upload videos to raise awareness about condom use and HIV testing in China [
26,
27]. In modern public health science, it may require multidisciplinary scientists to collaborate on problem-solving, data surveys, collection, and processing. Brabham described a framework for crowdsourcing adoption in public health from a four-type typology: knowledge discovery and management, distributed human intelligence tasking, broadcast search, and peer-vetted creative production [
16].
Based on the above analysis, we can illustrate the relations and the process of crowdsourcing applications for public health, as shown in
Figure 1. The application of crowdsourcing in the field of public health can be divided into five processes, including selecting crowdsourcing, organizing crowdsourcing communities, engaging the public to contribute, receiving and evaluating contributions, sharing solutions and implements. Crowdsourcing can provide not only online citizens, but also scientists with a variety of information. Leveraging the feasible and low-cost characteristics of crowdsourcing, online citizens can easily participate in public health activities and share their ideas/knowledge. Meanwhile, increasing numbers of medical and hospital diagnostic devices are now connected to the Internet, which allows scientists to track and monitor the behavior of the crowd, even without letting them know. When organizing a crowdsourcing community, mobile apps, social media (Twitter, Facebook, Weibo), online platforms and crowdsourcing contests are multiple paths for researchers to consider. The Amazon MTurk, a labor market platform, is mainly used to collect data or publish tasks. Crowdsourcing contests have become an effective public health engagement tool, which has been utilized to conduct medical experiments. The real power and uniqueness of crowdsourcing adoption in public health is surveying, data processing, surveillance, and problem-solving. Specifically, crowdsourcing can contribute to three domains: health promotion, health research, and health maintenances. Finally, crowdsourcing sponsors can share solutions and applications in order to improve public health.
Most of the previous studies have only conducted experiments to explore the function of crowdsourcing in the specific field of public health, such as improving public awareness of sexual health, obtaining solutions to medical problems, and collecting medical big data, etc. Limited studies have been published related to a systematic review or overview of crowdsourcing for public health. Among them, some studies extracted data from reports via PubMed, EMBASE, and Google, but no research has utilized the Web of Science (“WOS”) database. The systematic review by Ranard et al. illustrated the scope of crowdsourcing in health and medical research, but only contained 21 studies [
19]. The narrative review by Swan explained the adoption of crowdsourcing in health research studies up to 2011 [
13]. Moreover, no scholars carry out bibliometric analysis on the application of crowdsourcing in public health or related topics. This study uses a bibliometric approach to analyze the adoption of crowdsourcing in the field of public health and presents research hotspots, evolution history and emerging trends. Using co-citation analysis and co-occurrence analysis, we look at the Web of Science (“WOS”) publication data related to crowdsourcing and public health from 2006 to 2019.
This study may contribute to existing research from three aspects. First, this study is the first bibliometrics analysis of crowdsourcing applications for public health using CiteSpace software. We use bibliometric analysis to provide a new insight that was not conducted comprehensively in previous studies. Second, we offer a better understanding of the emerging trends of the adoption of crowdsourcing in the field of public health, through summarizing the role of crowdsourcing in public health. Third, the analytical framework and the results concluded in this study will provide research basis and directions for future bibliometric analysis in public health ecosystem. As this study explores the general application of crowdsourcing in public health, it could serve as a sound foundation for future research that focuses on the specific roles of crowdsourcing in concrete tasks, e.g., surveying, data processing, monitoring, etc.
The rest of this study is organized as follows.
Section 2 introduces the materials and methods.
Section 3 conducts the time and space scope analysis of crowdsourcing research in the field of public health. Knowledge domains and emerging trends of crowdsourcing’s application in public health is displayed in
Section 4.
Section 5 draws the main conclusions of this study and points out future research directions and limitations.
5. Conclusions
From a multi-dimensional, time and dynamic perspective, we use CiteSpace V to analyze the development trends and hotspots of crowdsourcing as applied to public health. This study has shown that crowdsourcing is a relevant topic, particularly in recent years and in the field of public health. As we know, this paper is the first bibliometrics analysis of crowdsourcing applications for public health using CiteSpace software. The results in this study contribute from several aspects to our current understanding.
First, with regard to the scope of time and space, the amount of crowdsourcing literature has grown sharply, and the application of crowdsourcing has spread to many domains, especially in public health and health communication. At present, the United States occupies a leading position in the domain of crowdsourcing research for public health, followed by England and China. Scholars from the Guangdong Provincial Center for Disease Control and Prevention cooperate with American universities to apply crowdsourcing in sexual health communication and HIV prevention. They are the first research team that have made outstanding contributions to the application of crowdsourcing in the field of public health in China.
Second, according to co-authors and types of journals, Howe and Brabham are the two core authors in this field. The World Health Organization has also pointed out the effectiveness of crowdsourcing in some reports. In addition, the results of research on crowdsourcing applications for public health are mainly published in medical and comprehensive journals. Medical journals include the ‘Journal of Medical Internet Research’, ‘Lancet’, and ‘American Journal of Public Health’, etc.—comprehensive journals contain ‘Nature’, ‘Science’, and ‘PloS One’, etc.
Third, through co-citation analysis, the use of crowdsourcing in public health is increasing, particularly in preventive medicine, mental health, and personalized prevention, etc. The specific applications of crowdsourcing contain data processing, surveying, surveillance, and problem-solving. Further, the crowdsourcing model not only promotes the application of healthy big data and the construction of intelligent health platform but also pushes the online process of social medical crowdsourcing.
Finally, crowdsourcing research in this field focuses on four knowledge domains, namely crowdsourcing as a medium for Internet public health communication, the application of crowdsourcing in the field of prevention and treatment, the role of crowdsourcing in the public health care ecosystem, and applied research of crowdsourcing competitions in infectious diseases and epidemiology. In addition, there are several future research directions to discuss. The first one is the application of other databases for bibliometric analysis, such as Google Scholar, which contains citations available in sources other than the WOS. Second, the WHO emphasize the importance of crowdsourcing competitions to improving public health. Hence, future studies can evaluate the role of crowdsourcing competitions/contests in public health development. Final, future research can consider ethical concerns because personal data and diagnostic results may be shared in the process of crowdsourcing.
Our study has some limitations. On the one hand, we did not search the gray literature to identify some unpublished studies. On the other hand, we only consider online crowdsourcing, not including research without the Internet. Therefore, we may underestimate the number of studies adopting crowdsourcing in public health.