Definition of Health 2.0 and Medicine 2.0: A Systematic Review

Background: During the last decade, the Internet has become increasingly popular and is now an important part of our daily life. When new ―Web 2.0‖ technologies are used in health care, the terms ―Health 2.0" or "Medicine 2.0‖ may be used. Objective: The objective was to identify unique definitions of Health 2.0/Medicine 2.0 and recurrent topics within the definitions. Methods: A systematic literature review of electronic databases (PubMed, Scopus, CINAHL) and gray literature on the Internet using the search engines Google, Bing, and Yahoo was performed to find unique definitions of Health 2.0/Medicine 2.0. We assessed all literature, extracted unique definitions, and selected recurrent topics by using the constant comparison method. Results: We found a total of 1937 articles, 533 in scientific databases and 1404 in the gray literature. We selected 46 unique definitions for further analysis and identified 7 main topics. Conclusions: Health 2.0/Medicine 2.0 are still developing areas. Many articles concerning this subject were found, primarily on the Internet. However, there is still no general consensus regarding the definition of Health 2.0/Medicine 2.0. We hope that this study will contribute to building the concept of Health 2.0/Medicine 2.0 and facilitate discussion and further research.

term which includes consumer-directed ‗medicine' or Health 2.0.‖ More and also more specific definitions of Health 2.0 and Medicine 2.0 exist [16,17]. However, these definitions seem to have evolved together with the increased use of the definitions and the different parties involved in Health 2.0 and Medicine 2.0. Ricciardi stated, -Everyone is trying to grasp what Health 2.0 exactly is‖ [26]. Does Health 2.0 refer to patients or to professionals or both? Does it focus on health care in general, or does it address specific aspects of health care like preventive or curative care, acute or chronic illness? Several authors concluded that there is no authoritative definition of the term yet, and Health 2.0 definitions and translations in practice remain murky and fragmented [27,28].
A clear definition is important for the development of new Health 2.0 or Medicine 2.0 initiatives and also for the comparability of new developments in research. Therefore, the aim of this study was to identify definitions of Health 2.0/Medicine 2.0 and to gain insight into recurrent topics associated with these labels.

Methods
We performed a systematic literature study to find unique definitions of Health 2.0/Medicine 2.0 and identify and recurrent topics discussed in conjunction with these terms.

Search Strategy
First, we searched the following electronic databases: PubMed, Scopus, and CINAHL. For each database, we searched all available years through September 2009. Since there was no relevant MeSH term available for Health 2.0 or Medicine 2.0, we used the following search terms: health 2.0, health2.0, health20, medicine 2.0, medicine2.0, medicine20, Web 2.0, Web2.0, Web20 (Table   1). We scanned the reference lists for relevant articles (the snowball method), contacted individual experts in the field, and inquired after relevant publications.
Second, we searched for gray literature on the Internet using the search engines Google, Bing, Yahoo, Mednar, and Scopus. Mednar and Scopus were used because they focus on scientific literature. Google, Bing, and Yahoo were used because these are the most widely used search engines [29,30]. We used the advanced search option, selected English as the preferred language, and turned the option for regional differences off. Based on earlier research [16], we expected a large number of results. Therefore we added a more specified search string query for Google, Yahoo, Bing, and Scopus (

Inclusion Criteria
Subsequently, a combination of three of the authors (TB and LE and LS or SB) independently assessed the retrieved studies and gray literature for inclusion. Sources were included if a definition of Health 2.0 or Medicine 2.0 was identified. Disagreement over inclusion between the reviewers was resolved through discussion.

Data Extraction
TH and LE independently assessed the included studies and gray literature and extracted unique definitions. A predesigned table was used to ensure standardized data extraction. For each definition we noted author, source, and year (Table 3). After completing the table, we used the constant comparison method to explore possible topics of Health 2.0 and Medicine 2.0 [34]. We independently analyzed the definitions and identified recurrent topics by using -coding.‖ Described by Strauss and Corbin, coding is an analytical process through which concepts are identified and dimensions are discovered in data [35]. The results are displayed in Table 4.
In the following paragraphs we describe these recurrent topics from these definitions in more depth.

Patients and Consumers
The first main topic was -patients‖ or -consumers of health care,‖ which was found in 35 definitions. Of these, 12 included mention of either increased participation or empowerment of patients. The following terms or phrases were identified: increased consumer/patient participation [18,27,49,50,58], patients can actively participate [63], and participatory [42,45], patient empowerment or consumer empowerment [41,49,59,62]. The other 23 mentioned only patient or consumer involvement and not the effects. -Mashing‖ was seen as combining two or more Web 2.0 sources to create a new one. Other definitions indicated that the concept of Health 2.0 originated from a combination of the concepts -health‖ and -Web 2.0‖ [17,40].

Professionals
The third topic that was identified concerns -professionals‖ or -caregivers,‖ and was found in 26 definitions. Of the 46 included definitions, five mentioned increased participation or empowerment of professionals. The following terms were found: -professional empowerment‖ [49,52,59], -empowerment of the individual‖ [48], and -empowerment of the user‖ [3].
Besides patients and professionals, other stakeholders were mentioned. However, they were mentioned less frequently and therefore not included in Table 4

Social Networking
The fourth topic, the emergence of online communities and social networking, was reflected in 22

Change of Health Care
Fifth, we found that change of health care was described by 15 definitions. According to the definitions, Health 2.0 means change of health care: -a whole new way of involving consumers in the health care system‖ [64], -next generation of health care services‖ [67], -new and better health system‖ [18], -new concept of health care‖ [52], -all constituent focus on health care value and on improving safety, efficiency and quality of health care‖ [61], -shaping health care with Web 2.0 tools‖ [17], and -new wave of innovation‖ [62]. Change was described differently: -reshaping health care‖ [17,42], -ever changing‖ [66], -continually evolving cycle‖ [49], -evolution of technology and medical industry‖ [36], -evolution of health care‖ [41]. Change was also described as -revolutionary‖ [55], while another author stated, -we should be careful not to assume that a revolution has occurred in health care‖ [27].
We also found one author who referred to -user generated health care‖ [25].

Collaboration
The sixth topic, mentioned in 14 definitions, was collaboration. In the Health 2.0 era, patients will actively contribute to their own care process. Collaboration between professionals and patients may -collaborate‖ [52,71], -collaborative practices‖ [16], and -collaborate and share knowledge‖ [70] to -working together‖ [39].
There were also other aspects described with regard to the relationship among stakeholders.
Patients would transform their role in health care [26] and would be on the same level of playing field as other stakeholders [38]. A role change of patients and professionals was also indicated. For example, the following phrase was used: -doctor and patient positioned together‖ [37]. Patients were described as -active contributors‖ [55], -active and responsible partners‖ [25], or -active partners‖ [42]. Another author mentioned -integration of patients and stakeholders‖ [45].
[view this  Although some authors indicated that little or no differences existed between the two terms [16,18,27,55], others saw differences, for example that Medicine 2.0 is focused on the relation between professionals and patients whereas Health 2.0 is focused on health care in general [17,52,65]. As most definitions described Health 2.0, this term may be more widely used and accepted than Medicine 2.0.

Discussion
Overall, we found that the term Web 2.0 was mentioned often: 33 authors used the term directly in the definition, which suggests that they accepted this concept. However, others state that Web 2.0 does not exist at all [72]. information. Moreover, other relationships might also change; for example, the appearance of online communities could change the relationship between health professionals and specific groups of patients. This has been termed collaborative health care [18].
Finally, it is expected that Health 2.0/Medicine 2.0 will lead to change of health care. Expectations concerning the speed of this change ranged from a -gradual shift‖ [27], an -ever changing‖ [66] or -continuous interactive process‖ [49] to -revolution‖ [55]. However, we advise caution in assuming that a revolution has taken place [27]. It may be that communication, information exchange, and patients' contribution to his or her care has improved or accelerated, but according to Engelen [8],

Limitations
Our study has some limitations. First, we found 46 unique definitions, mostly in the gray literature, using the Internet. Only 9 definitions were found in peer-reviewed articles in the scientific literature. This can be explained by the fact that Health 2.0/Medicine 2.0 is a relatively new concept and is still developing. However, it is important to realize there is no evidence-based method available to determine the quality of online content yet. Consequently, proper assessment of the value of the definitions we found was not possible.
Second, it appeared that searches using Google, Bing, and Yahoo showed many results. Although these search engines displayed results by relevance using algorithms and ranking systems, we may have missed unique definitions as we only studied the first 100 results.
Finally, the exact way search engines display results remains unclear. The process can be seen as a black box. As a result, reproduction of searches is far from optimal, as the results literally change every second. Therefore, one might question the suitability of these search engines for scientific research. However, by combining the results of Google, Bing, and Yahoo and using four search queries, we believe we found the majority of all relevant definitions in the gray literature.