also hold their own implications for community dynamics. trust and safety the sharing of any personal information within a community is often impacted by the level of trust those community members have for each other. distributing personal information can have many consequences if it is not handled properly. not only does it decrease ones security, but it can also threaten their safety. in in-person communities, trust is often predictably built over time, and can lead to the open exchange of valuable personal details that can facilitate the exchange of support and other resources. however, in online health communities, many individuals do not know each other personally, and also perceive their health information as a very personal and private subject. for people to receive the benefits discussed previously, they need to over come this barrier in online health networks and build a strong feeling of trust. within these networks, potential factors that contribute to feelings of cognitive and affective trust include perspective taking, self-efficacy, and network density. adoption and engagement there has been a wide and rapid adoption of online health communities from patient populations. however, some of the greatest benefits are realized when these communities also are utilized by medical professionals. for patients, there is a clear incentive to increase information, support, and care through these communities. however, there is less of an incentive for medical providers to participate. doctors can be slow to adopt technologies that deviate or disrupt their regular patterns for providing care. the additional time and responsibility commitments and significant barriers to adoption of these communities for medical providers. furthermore, a common issue with online health communities is a lack of engagement from those with medical conditions, even after they have decided to adopt the technology. users often don't feel they have an obligation to share or create new content, even if they consume content from other individuals. two major reasons for this behavior are (1) a lack of social responsibility to contribute, and (2) concern about how other may perceive them if they did decide to contribute. several options for addressing this are shown to be effective. for example, if people are paired with an online "buddy" as part of the larger community, they are more likely to contribute as it can help give a larger sense of social responsibility. nevertheless, driving adoption and engagement is a major hurtle for many online health communities. accessibility for the benefits of online health communities to accrue, systems must be developed that are accessible, welcoming, easy to navigate and use, and able to help members discern information quality and interact with other participants in meaningful ways. the successful design of such systems will be facilitated by collaborations among clinicians, informed designers, and patients. health professionals and patients can help explain the physical and emotional stages that individuals go through once they are diagnosed with a particular disease. furthermore, health professionals understand the risks of misinformation and the role that health care providers need to play. patients understand the practical information about coping with a disease and the importance of social support and empathy. designers and developers are needed to understand and explain the technological options available to online health communities and the implications of specific design choices. such collaborations are needed to explore topics on which there seems to be no prevailing wisdom, such as how the nature of the disease or illness impacts the online health community design; how to improve health literacy; and which of the many collaborative technologies that are available best support peer interaction. finally, it is important to track and evaluate new technologies, such as web 2.0, to understand when and how to deploy technologies that assist in and improve peer health communication. at the same time, access and effective use by others may be restricted due to cultural, language, and other issues. participation an obvious factor for any online community is managing user participation, engagement, and behavior. different people have different experiences with online health communities, which can lead to differing impacts and implications. some individuals show high engagement, while others are more passive in their use (lurkers). understandably, individuals who showed much higher levels of engagement reap the highest benefits in outcomes such as emotional support, help giving, and emotional expression. that said, even lurkers can see some beneficial level of peer support from the online communities. beyond the extent to which people participate in these communities, there is also a distinction in the type of engagement that is seen by those who actively participate. some individuals more frequently share general health information such as hospital information, drug side effects, and health behaviors. whereas, other individuals choose to share more specific knowledge such as their private health information. private information can be more valuable for other patients. however, it is also much more difficult to share than general knowledge. regardless of the type of knowledge being shared, reputation, social support and sense of self-worth all were associated with more sharing. furthermore, face concern, which is the extent to which a person values the protection and improvement his or her positive social image, promotes general knowledge sharing and inhibits private sharing. emotions, time, and effort are some of the largest barriers to providing private knowledge. beyond these factors, there are also various other structural factors that may impact community participation and engagement. in some online health communities, health experts are incorporated as moderators in order to provide people with accurate clinical knowledge. inclusion and participation from moderators can help create a more empathic community culture. however, the inclusion of moderators can also give users feelings of inequality if posts do not receive equal responses. in addition, determining which post need clinical expertise, and which would suffice with community expertise is not an easy task, and can cause further issues. from this, when users do receive a response it can mislead them about what kind of consultation they are receiving. while moderators are often put into place to help guide the conversation and flow of information in these communities, there are also users that occasionally adopt this role naturally. these influential users have accumulated the power to drastically influence other users and the community as a whole. for example, influential users can help build and manage a community, provide marketing, initiate community driven campaigns, and disseminate information. while these factors help explain the experience and participation of users during a very particular point in their lives, there are also several factors to consider about the experience of patients who stop using or participating in these communities over time. based on the benefits that these communities can offer, removing yourself from them could stifle the beneficial effects. there are numerous reasons for why someone might stop participating in a community, such as a lack of need, a poor experience, or a failure of a sites design. however, some argue that oftentimes these situations are caused by a logical progression of life changes as a given person's experience with his or her condition evolves. regardless of the reasons for leaving, both the participation and non-participation of a communities members is a very important factor to consider, as it has strong implications for the overall success of the community. forms as mentioned previously, these communities are distinct from general online communities in that they focus exclusively on health-related topics for those currently navigating the world of diseases, illness, and medicine. furthermore, they also differ from other health-related sites that only allow users to retrieve information. the main hallmark of these communities is that they allow for communication between multiple people. that said, they can take a variety of forms, and vary drastically in their scope. these online health communities can be formed across numerous different types of communication platforms such as blogs, chats, forums, wikis, and social media sites. as long as people are able to communicate with each other over the internet about medical conditions, any given communication platform can be used to create an online health community. beyond the platform used, communities can also vary in terms of how open and accessible they are. some communities are open and public to anyone who is interested, while others are very private. furthermore, some communities focus on multiple conditions, while other focus primarily on one. finally, the target user population can also differ between networks. for example, some communities are targeted towards older adults, while others are exclusively for adolescents. features in terms of functionality, there are several primary features that most online health communities possess. the primary feature that most online health networks have are those that support social learning and networking. communication is at the core of these communities. this communication can take the form of both one-to-one communication and one-to-many communication. oftentimes they feature discussions on practical problems faced by people during their condition such as depression, side-effects of medications, etc and answers to those problems provided by other members. another feature type that most online health committees have are those that allow for information distribution. these features often can take the form of a blog, news area, staff-written articles, or even a regularly scheduled email newsletter. these features can allow for the exchange of important information such as recommendations and feedback about certain medications or medical procedures. a third common feature type are those that allow for guidance. these guidance features often take advantage of the one-to-one and one-to-many communication features mentioned previously. some communities have specific features that facilitate guidance from medical professionals, while others provide specific tailored mentoring or coaching. while less common, a fourth feature types that is sometime available in online health communities are those that are designed to drive more user engagement. examples of these kinds of features include features such as gamification or social recognition. finally, another less common feature type are those that allow for the sharing of personal health information. some community sites allow users to enter or upload specific health information, and share that with other users. this type of feature may raise some privacy and safety concerns for some, which may be why it is not as prevalent as some of the common features. example communities smart patients patientslikeme healthboards medhelp dailystrength webmd giveforward healthunlocked inspire