Study	Main aims	Type of study, methods, topic, population	Included papers & main findings
Balatsoukas et al, 2015 [ 35 ]	To review research on integration of expert-led health promotion interventions with online social networking sites (SNSs).	• Scoping search and systematic narrative synthesis. • The effectiveness of SNS for health promotion. • Various (adults, families, students, general web users, office workers, patients, children and parents, youth, teenage girls, adolescents).	• 42 papers included. • 26 papers evaluated effectiveness; 6 RCTs, 4 observational, 14 pilot studies, other (2). • RCTs showed no clear effect of SNSs; more positive effects on both self-reported and objectively measured behaviour change were reported in pilot studies. • There are positive effects on emotional health if positive experiences are shared. However, this can also be negative, due to contagion of negative emotions.
Benetoli et al, 2015 (Australia) [ 16 ]	To investigate the use of SM in professional pharmacy practice and pharmacy education, and include evaluation of research designs.	• Systematic review and narrative synthesis. • Use of SM to enhance e-professionalism and pharmacy education. • Pharmacists (educators, preceptors, interns and students).	• 24 papers included. • Survey methods were used in 17 studies; focus groups in two; interviews in one; and direct observation in seven. • The use of SM in pharmacy is increasing but findings are not generalizable to other countries. • SM in general and SNSs were used mainly for personal reasons. Wikis, Facebook, and Twitter were used in pharmacy education with positive feedback from students.
Best et al, 2014 (UK) [ 36 ]	To examine the influence of SM on adolescent well-being.	• Systematic narrative review and theoretical framework. • The influence of SM on adolescent well-being. • Adolescents (over 19 y/o excluded; mean age of 19).	• 43 papers included. • Survey research (55%), followed by qualitative (12%), longitudinal (12%), content analysis (11%), experimental (4%), case control (3%) and mixed method studies (3%). • SNSs can be beneficial and harmful for mental wellbeing. • Benefits include increased self-esteem, perceived social support, increased social capital, safe identity experimentation and increased opportunity for self-disclosure. Harmful effects were increased exposure to harm, social isolation, depression and cyber-bullying.
Brunner et al, 2015 (Australia) [ 17 ]	To examine the use of SM on patients with traumatic brain injury (TBI).	• Systematic review with qualitative synthesis. • The benefits, harms; barriers, facilitators of SM use in patient populations who have had a TBI. • Patients with TBI.	• 16 papers included. • Conference abstracts/proceedings (43%), qualitative studies (19%), qualitative descriptive studies (13%), systematic review (6%), case series (6%), thesis (6%), narrative literature review (6%). • SM use in TBI rehabilitation can increase social support; further investigation is needed into the benefits of SM for social support. There is little information on the use of SM in TBI patients after injury. Online safety is a risk and cognitive and behavioural disabilities are barriers.
Campos et al, 2016 (Mexico) [ 51 ]	To examine use of SM by the elderly to promote independent living, social integration, to improve health, reduce cognitive decline, and prevent early death.	• Systematic review. • Use of ambient and SNSs in social integration of the elderly / older adults. • Elderly populations.	• 53 papers included. • Controlled trial (24), non-controlled (5), case series, 2), controlled case series (4), other (18). • There was an increase in participation of older adults in SNSs who can benefit from the use of ambient and social technologies. Different technologies have been suggested to socially integrate the elderly, but they can be expensive. • SNSs are a way to promote socialization of elderly adults.
Capurro et al, 2014 (Chile) [ 48 ]	To identify the best uses of SNSs for public health research and practice and to identify gaps.	• Systematic review. • Use of SNSs for public health research and practice. • Hard-to-reach populations (adolescents, patients with chronic non-communicable diseases and individuals at risk for STDs and HIV).	• 73 papers included. • Cross-sectional observational (63), RCTs (4), systematic review (1), other (5). • Use of SM is increasing but difficult to measure its effects. Issue is mostly studied in high-income countries. • SM may be effective in studying diverse populations, in sexual health and alcohol, tobacco or substance abuse.
Cartledge et al, 2013 (UK) [ 37 ]	To examine implementation of SNSs as interventions in healthcare education; use of SNSs by students for educational purposes.	• Systematic review. • Use of SNSs in medical education. • Medical, pharmacy and nursing students. Undergraduates and post-grads in health.	• 9 papers included studies. • This review examined 9 case studies where SM was used in medical education. • Medical educators can use SM to benefit learning. There were no problems with professionalism and positive feedback was received from learners. • However, there was no solid evidence that SM is equally or more effective than other media in medical education.
Chang et al, 2013 (USA) [ 26 ]	To systematically describe the use and impact of social media in online weight management interventions.	• Systematic review. • Effects of SM in online weight management. • Adults	• 20 papers included. • RCTs (20). • Few studies measure the effects of SM in online weight management interventions; its impact is still unknown. • Findings are consistent with previous systematic reviews on Internet-based behavioral interventions and electronic peer-to-peer support group interventions, which have found that the effect of the technology being studied was not isolated; thus, their effectiveness is not known.
Charles-Smith et al, 2015 (USA) [ 27 ]	To identify and target specific SM tools to use in public health interventions.	• Systematic review. • The use of SM in disease surveillance practice and outbreak management to support public health. • General population.	• 60 papers included. • Case studies, cohort studies, retrospective studies. • SM is shown to be effective in improving public health, and may be effective at disease surveillance, and at identifying adolescent populations displaying substance abuse, especially alcohol, sexual behaviour. SM can improve community health outcomes for at-risk adolescents. • Public health should integrate SM analytics into disease surveillance and outbreak management practice.
Chen et al, 2016 (Hong Kong) [ 45 ]	To examine the effects of ICT interventions on reducing social isolation of the elderly.	• Systematic review using narrative synthesis. • The effects of SM on one or more attributes of social isolation among elderly. • Elderly populations.	• 25 papers included. • RCTs (6), cohort studies (6), surveys (4), other (9). • SM tools may be effective in tackling social isolation of the elderly, but not for every senior. Usage should be tailored and other platforms should be studied empirically. • Research on other types of ICTs (eg, mobile phone–based instant messaging apps) should be conducted to promote understanding of ICT-based social-isolation interventions for the elderly.
Cheston et al, 2013 (USA) [ 28 ]	To examine the use of SM in medical education to determine outcomes, challenges and opportunities.	• Systematic review. • The use of SM interventions in medical education. • Medical students in all years, physicians, specialists, residents, fellows.	• 14 papers included. • Nine studies (64%) used a single-group cross-sectional or posttest design, whereas four studies (29%) employed a two-group nonrandomized design. One RCT (7%). • SM is associated with improved exam scores, attitudes (e.g., empathy), and skills (e.g., reflective writing). • Opportunities related to incorporating SM were promoting learner engagement (71% of studies), feedback (57%), and collaboration and professional development (both 36%). • Commonly cited challenges were technical issues (43%), variable learner participation (43%), and privacy/security concerns (29%).
Dyson et al, 2016 (Canada) [ 43 ]	To examine the use of SM in deliberate self-harming behaviours.	• Systematic review. • The use of SM related to self-harm or suicidality in children and / or adolescents • Teens and adolescents aged 12 to 21.	• 26 papers included. • Cross-sectional observational (19%), descriptive (35%), qualitative (42%), mixed (4%). • SM can create a sense of community and platforms used by those who ‘self harm’ are described as supportive. • Support included suggestions for formal treatment, advice on stopping self-harming behaviour, and encouragement. Harms included normalizing and accepting self-harming; discussion of motivation or triggers, concealment, suicidal ideation or plans; and live depictions of self-harm acts.
Eysenbach et al, 2004 (Canada) [ 42 ]	To compile and evaluate the evidence on the effects on health and social outcomes of computer-based peer-to-peer (P2P) communities and electronic self-support groups.	• Systematic review. • The effect on health & social outcomes of P2P online support and electronic self-support groups. • Adults and patients.	• 45 papers included. • 20 RCTs, 3 meta-analyses, 2 non RCTs, one cohort study, and 11 before and after studies, other. • The outcomes measured most often were depression and social support; but most studies showed no effect. There is no evidence to support concerns over SM harming people. • "Effect" of P2P communities is unclear. Studies are confounded by effects of co-interventions.
Ghanbarzadeh et al, 2014 (Australia) [ 18 ]	To examine various 3D virtual worlds in health and medical contexts and categorize them into meaningful categories.	• Systematic review. • The application of 3DVW in healthcare. • Healthcare communities and researchers.	• 62 papers included. • Study types of the papers were not mentioned. • 3DVWs offer innovative ways to perform health activities within six categories: academic education, professional education, treatment, modeling, lifestyle, and evaluation. • Most research focused on education in health care, and most studies were undertaken in just two countries, the United States and the United Kingdom.
Gold et al, 2011 (Australia) [ 19 ]	To examine the extent to which SNSs are used for sexual health promotion and describe the breadth of these activities.	• Systematic searches and content analysis of SM sites. • The use of SNSs for sexual health promotion. • Young people (no age ranges given).	• 178 activities included. • Study types are not applicable. • SNSs are being used to deliver health promotion, although the activities have not been described or evaluated for their effectiveness in improving health outcomes. • Recommends cost-effectiveness studies in the future.
Golder et al, 2015 (UK) [ 38 ]	To summarize the prevalence, frequency and comparative value of information on the adverse events of healthcare interventions from user comments and videos in social media.	• Systematic review using narrative synthesis. • The number and frequency of sharing adverse events on SM and user comments. • Population not mentioned.	• 51 papers included. • Studies assessed over 174 social media sites with discussion forums (71%) being the most popular. Adverse events in SM varied from 0.2% to 8% of posts. • There are more adverse events in SM, particularly in sharing ‘symptom’ related and ‘mild’ adverse events. • Cost-effectiveness analysis of all pharmacovigilance systems, including social media is urgently required.
Griffiths et al, 2009 (Australia) [ 20 ]	To review the available evidence concerning the effect of Internet support groups (ISGs) on depressive symptoms.	• Systematic review. • The use of ISGs by patients with depression. • Patients with a depression diagnosis.	• 31 papers included. • More than half of the studies reported a positive effect of ISGs on depressive symptoms. However, only two (20%) of these studies employed a control group. • Studies with lower design quality tended to be associated with more positive outcomes (P = .07). Overall, studies of breast cancer ISGs were more likely to report a reduction in depressive symptoms than studies of other ISG types.
Househ et al, 2014 (Saudi Arabia) [ 55 ]	To explore the range of SM platforms used by patients and examine the benefits and challenges of using these tools from a patient perspective.	• Systematic review. • The use of SM platforms as used by patients. • Patients and health consumers.	• 12 papers included. • Four studied programs or interventions that use SM; three focused on literature reviews, three were observational, one was a survey, and one was conceptual in nature. • SM can have a positive effect in community engagement, information sharing, data collection, appointment setting, prescription notifications, providing health information, engagement of the elderly, improved participation, autonomy, motivation, trust, and perceived self-efficacy. • Concerns are privacy, security, the usability of social media programs, manipulation of identity, and misinformation.
Jin et al, 2014 (Hong Kong) 46]	To examine the effects of educational technologies on student learning and staff engagement in problem-based learning.	• Systematic review. • The use of educational tech in problem-based learning. • Postsecondary students and tutors in medicine, dentistry, speech and hearing sciences.	• 28 papers included. • The review demonstrates the generally positive effect of educational technologies in PBL. Positive outcomes for learning include providing rich, authentic problems and/or case contexts for learning; student development of medical expertise; making disciplinary thinking explicit; providing a platform to elicit articulation, collaboration, and reflection; reducing perceived cognitive load. • Limitations included cumbersome scenarios, infrastructure requirements, and the need for staff and student support in light of the technological demands of new affordances.
Jones et al, 2014 (USA) [ 29 ]	To examine the effectiveness of SM and text messaging interventions designed to increase sexually transmitted disease (STD) knowledge.	• Systematic review. • The use of SM to increase STD knowledge and reduced risky behaviours. • Young adults aged 15 through 24 years.	• 11 papers included. • RCTs (6), feasibility study (2), pre/post-test design (3). • There is some evidence indicating that SM and text messaging increases knowledge regarding the prevention of STDs. The interventions may also affect behaviour, such as screening/testing for STDs, sexual risk behaviors, and STD acquisition, but the evidence for effect is weak.
Koskan et al, 2014 (USA) [ 30 ]	The use and taxonomy of SM in cancer-related studies.	• Systematic review. • The use of SM by cancer patients, and its impact on the digital divide and health literacy; cancer disparities. • Cancer care communities	• 69 papers included. • Use of SM in cancer from 1996 to 2007 focuses on discussion forums, message boards and support group websites. By 2008, researchers began to view the benefits of blogging during cancer treatment and survivorship. Intervention studies were not reported until 2010. • Most research analyses the content of SM forums where users asynchronously post or respond, share resources, reliable cancer information or emotional support. • Adults aged 18 to 49 make up large group using Facebook and Twitter which might be useful for cancer screening.
Laranjo et al, 2015 (Portugal) [ 54 ]	To examine the use and effectiveness of interventions using social networking sites (SNSs) to change health behaviours.	• Systematic review and meta-analysis. • Effectiveness of SNSs in changing health behavior-related outcomes. • Participants were diverse in age; three studies recruited students, and two studies involved young adults.	• 12 papers included. • RCTs (9), quasi-experimental (3) studies. • Overall, SNS interventions appear to show statistically significant effect in promoting health-related behaviours. • Most studies evaluated multi-component interventions, posing problems in isolating specific effects of SNSs. • Health behavior change theories were seldom mentioned but two innovative studies used 'network alteration', showing a positive effect.
Luo et al, 2015 (Hong Kong) [ 47 ]	To examine the effectiveness of social networking interventions (SNIs) in HIV prevention.	• Systematic review. • Effectiveness of SNIs as an intervention in HIV prevention. • Sexually active young adults, teens.	• 11 papers included. • RCTs (11). • The strength of using SN in HIV prevention is moderate. Some studies show SNIs help high-risk populations modify their behaviours. There is insufficient evidence overall.
Maher et al, 2014 (Australia) [ 21 ]	To systematically review the current level of evidence regarding the effectiveness of online social network (OSN) health behaviour interventions.	• Systematic review and qualitative synthesis. • Uses of OSNs to deliver health behaviour change interventions. • Adults or children were included, regardless of health status (healthy, or participants with specific health conditions or diseases).	• 10 papers included. • RCTS (6), pre-post studies (4) using a mix of health social networks (n=2), research OSN websites (n=3), and multi-component delivered via pre-existing OSNs (Facebook n=4 and Twitter n=1). Nine studies reported significant improvements in aspects of health behaviour change. • Effect sizes were small and statistically non-significant. Engagement in studies was relatively low, 5-15% fidelity. • It is unclear whether OSN-based interventions are equally useful for all health behaviours, for the long term, or whether they may be more effective for some than others.
Mita et al, 2016 (New Zealand) [ 53 ]	To synthesize evidence of the effect of SM use compared with no use as part of interventions to reduce risk factors for non-communicable diseases.	• Systematic review. • Use of SM in reduction of non-communicable disease risk factors. • Varied. No population restrictions.	• 16 papers included. • SM is used with low levels of media richness and presence (e.g., discussion boards, bulletin boards). Trials assessing SM interventions aimed at modifying risk factors for non-communicable diseases showed SM use improved primary outcomes, but poor study quality limits generalizability. • Further trials should isolate effects of SM and effects of media richness of platforms. Studies that integrate SM into interventions had a greater effect for primary outcomes (ie., for weight loss, physical activity, healthy eating).
Moorhead et al, 2013 (UK) [ 8 ]	To identify the uses and benefits, limitations of social media for health communication.	• Systematic review. • Uses and benefits of SM in health communication. • General public, patients, health professionals (children, teens, patients, seniors, and/or health providers).	• 98 papers included. • There are some benefits to using SM in health communication such as increased interactions, greater access to tailored information, peer support, public health surveillance, and potential to influence public policy. • Health information on SM needs to be monitored for quality and reliability; users’ confidentiality and privacy need to be maintained. Eight gaps in the literature and key recommendations for future research were provided.
Odone et al, 2015 (Italy) [ 49 ]	To summarize the evidence on the effectiveness of SM interventions to promote vaccination uptake and coverage.	• Systematic review. • Use of information technologies to promote vaccination and immunisation. • Parents/children eligible for immunization.	• 19 papers included. • RCTs (7), non-RCTs (5), cross-sectional (3), operational research (3), case-control study (1). • Text messaging, patient portals and computer reminders may increase rates of vaccine-immunization. Youth are willing to use Facebook for health-related reminders. • Data is insufficient overall on the effects of SM, email and smartphone applications. However, it is estimated that youth in 18-29 y/o group receive 87.7 messages a day.
Patel et al, 2015 (UK) [ 39 ]	To evaluate clinical outcomes from applications of contemporary SM in chronic disease; develop a conceptual taxonomy of SM uses.	• Systematic review. • Uses (and categorisation) of SM in chronic disease. • Adults (more than 18 years of age).	• 42 papers included. • Quantitative(27), qualitative(12), mixed method studies (3) • Overall impact of social media on chronic disease was variable, with 48% of studies indicating benefit, 45% neutral or undefined, and 7% suggesting harm. Among studies showing benefit, 85% used Facebook or blogs, and 40% were based within the domain of support. Using social media to provide social, emotional, or experiential support in chronic disease, especially with Facebook and blogs, appears most likely to improve patient care.
Rolls et al, 2016 (Australia) [ 22 ]	To review use of SM by health professionals in developing virtual communities that facilitates professional networking, knowledge sharing, and evidence-informed practice.	• Systematic searches with integrative review synthesis. • The use of SM by health professionals for a variety of purposes such as information-sharing and networking. • Health care professionals (physicians, nurses, midwives, pharmacist, social worker, allied health personnel).	• 72 papers included. • 44 qualitative, 20 mixed methods, and 8 literature reviews. • There is emerging evidence that health professionals use SM to develop virtual communities and to share domain knowledge. These virtual communities, however, currently reflect tribal behaviors of clinicians that may continue to limit knowledge sharing.
Sawesi et al, 2016 (USA) [ 31 ]	To examine use of IT platforms and SM to engage patients in healthcare and change in health behaviours.	• Systematic review. • Education of young people and their health. • Adolescents and health professionals.	• 170 papers included. • RCTs (112), case study (7), cohort study (19), cross-sectional analysis (15), quasi-experimental trials (17). • IT platforms can enhance patient engagement and improve health outcomes. 88.8% (151/170) of studies showed positive impact on patient behaviour and 82.9% reported high levels of improvement in patient engagement. Only 47.1% referenced specific behaviour theories and 33.5% assessed usability of IT platforms.
Shaw et al, 2016 (Australia) [ 23 ]	To determine the use of SM as a health intervention in addressing the health of adolescents.	• Systematic review. • The uses, benefits and dangers of SM in adolescents. • Adolescents and health professionals.	• 3 papers included. • Facebook may provide the most effective access to adolescents but are moving to Twitter and Instagram. • The reviewed studies did not show significant positive or negative results from using Facebook interventions. • Adolescents have a tendency to progress to newer media, and often create a hidden “secret” world in using SM.
Smailhodzic et al, 2016 (Netherlands) [ 52 ]	To provide an oveview of the effects of SM use for health-related reasons on patients and their relationship with healthcare professionals.	• Systematic review. • The effects on patients (both positive and negative) of using SM. • Patients.	• 22 papers were included. • Quantitative (9), qualitative (7), mixed method (6) studies. • Uses of SM were for social support, emotional and esteem support, expression, network and information support. Effects of SM were enhanced psychological, enhanced subjective well-being (and diminished), addiction to social SM, loss of privacy, being targeted for promotion. • SM use by patients was found to affect the healthcare professional and patient relationship by leading to more equal communication between patient and provider, but increased switching of doctors, and suboptimal interaction.
Smith et al, 2014 (UK) [ 11 ]	To evaluate the use, attitudes and perceptions of both teachers and students towards SM platforms (Facebook and Twitter) in healthcare higher education practice.	• Systematic review. • Uses, attitudes and perceptions of SM use in healthcare. • Medical students in all years, physicians, specialists, residents, fellows, pharmacy, allied health.	• 16 papers included. • This review provides some qualified support for use of Facebook and Twitter in healthcare higher education as part of a “blended” approach to classroom teaching. • SM is used to enhance communication and increase accessibility, exposure and interactivity of students to real-world practices and expertise. • Students perceive SM to be of value, but the role of faculty members in a predominantly “social” community has been acknowledged as a potential conflict.
Song et al, 2014 (Korea) [ 50 ]	To explore the relationship between Facebook use and loneliness.	• Systematic review and meta-analysis. • The relationship between using Facebook and loneliness. • General Facebook users.	• 8 papers included. • Researchers observed a significant overall effect in the positive relationship between Facebook use and loneliness. • People who are lonely may use Facebook to enhance social resources they lack offline. Lack of social support may lead to loneliness, which in turn, leads to Facebook use. Lonely individuals may benefit from Facebook but more research is needed to examine its effects. • Excessive problematic use of SM is an important issue for future research because unhealthy, compulsive use is likely an important factor in using Facebook and feeling lonely.
Stellefson et al, 2013 (USA) [ 32 ]	To review effectiveness of Web 2.0 self-management interventions for older adults (mean age ≥ 50) with one or more chronic disease(s).	• Systematic review. • The use of SM as interventions for self-management in older adults. • Broad population of chronically ill older patients.	• 15 papers included. • RCTs (11), randomized cluster, quasi-experimental, cross-sectional, qualitative designs • Self-managed patients felt greater self-efficacy in talking to health providers and receiving feedback and support. Asynchronous tools (eg, email, discussion boards) and progress tracking were useful for self-management. • SM engagement may be associated with improvements in health behaviours (eg, physical activity) and health status. • Factors influencing long term use of SM are not yet understood. Dropouts may have led to distorted effects.
Swanton et al, 2015 (Australia) [ 24 ]	To examine effects of new media interventions on sexual health behaviours and factors moderating the effect on those behaviours.	• Systematic review and meta-analysis. • The effects of new media on changing sexual health behaviours. • Sexually active young adults, teens.	• 15 papers included. • Twelve studies examined the effects of new-media on condom use; nine looked at effect on STD testing. • SM interventions lead to increased condom use and STD testing but the effects were not homogeneous. Using SM to encourage testing is more effective with women than with men, and generally more effective in younger adults. • Interactivity, target population and study design influenced efficacy of the interventions.
Taggart et al, 2015 (USA) [ 33 ]	To examine the use of SM to communicate about HIV prevention and treatment.	• Systematic review. • Using social media to communicate about HIV prevention and treatment. • Social media users: health professionals, clinicians, general users having HIV-related interests.	• 35 papers included. • Qualitative (9), quantitative (11) and mixed method (15) studies. • SM is used among diverse users and the frequency of use, satisfaction and effects of SM varied across studies. • Access to information, communicability, anonymity, sense of social and emotional support are key reported benefits. • Technology barriers, lack of privacy, cost and lack of physical interaction are the main disadvantages.
Theng et al, 2015 (Singapore) [ 56 ]	To examine the use of video games, gamification and virtual environments in diabetes management.	• Systematic review. • The self-management of diabetes using video games and virtual media. • Patients living with diabetes.	• 10 papers included. • RCTs (3), quasi-experimental (5), focus group discussion (1) experimental (1). • Four studies employed video games as intervention, three utilized virtual reality environments and three studies adopted principles from gamification and relevant theory. • Overall, video games were effective in diabetes but drawing strong conclusions is a challenge. • Gamification and virtual environments increase patients’ intrinsic motivation and positive reinforcement.
Toma et al, 2014 (UK) [ 41 ]	To summarise the evidence surrounding the role of online social networking services in diabetes care.	• Systematic review and meta-analysis. • The use of SNSs to assess HbA1c as a measure of glycaemic control with Type 1 or Type 2 diabetes. • Patients with diabetes.	• 34 papers included. • SNSs can improve HbA1c control in diabetics. SNS offers a novel approach to improving glycaemic control compared with standard management especially in Type 2 diabetes. • SNSs may be more efficient for patients with Type 2 rather than Type 1 disease. Larger randomised controlled trials in addition to cost-effectiveness studies are needed to understand the use of SNSs in diabetes care.
Whitehead et al, 2016 (Australia) [ 25 ]	To assess the effectiveness of mobile phone and tablet apps in self-management of key symptoms of long-term conditions.	• Systematic review. • Use of mobile apps to improve disease-specific clinical outcomes. • Adult patients with long-term conditions.	• 9 papers included. • Apps were shown to be somewhat effective in improving outcomes for patients managing their chronic diseases, especially those with diabetes and chronic lung problems. • Barriers are language and literacy, cost, availability and connectivity; cost-effectiveness studies are needed to demonstrate the impact and value of apps. • Without good patient motivation and adherence, mHealth interventions such as apps are likely to be ineffective.
Williams et al, 2014 (Canada) [ 44 ]	To examine the use of SM to promote healthy diet and exercise in the general population.	• Systematic review. • The use of SM interventions to promote healthy behaviours. • Adult populations (mostly middle-aged Caucasian women of mid-to-high socioeconomic status).	• 22 papers included. RCTs. • SM is commonly used as an intervention but there is little evidence that SM interventions demonstrate a significant benefit for improving healthy diet and exercise. • Most research is from the US affecting generalizability. No significant differences between SM interventions and alternate or no intervention controls in promoting healthy behaviours. This may be due to low levels of participation and the difficulty in affecting behavioural changes as seen across different interventions. While initial positive changes may be seen, these are often not sustained.
Willis et al, 2016 (USA) [ 34 ]	To examine weight management interventions delivered by online social networks (OSNs) to improve body weight, body composition, and chronic disease risk factors.	• Systematic review. • Using OSNs in managing body weight and chronic disease risk factors. • Adult populations.	• 5 papers included. • In all 5 studies, weight loss, though modest, was statistically significant in OSN groups independent of intervention length. Three studies (60%) reported significant decreases in body weight when OSNs were paired with health educator guidance and support. • One study reported significant weight loss of ≥5%. There is great potential for weight management delivered through OSNs. Interventions supported by professional guidance generate a more positive effect than self-guided OSNs. • To date, cost-effectiveness of OSN interventions in weight management has not been evaluated.