a b s t r a c tAnalyzing nationally representative online panel survey data during the MERS outbreak in South Korea, this study examined the role of social media exposure in shaping public's risk perceptions of MERS. The present study also investigated the moderating role of heuristic-systematic processing and self-efficacy in the relationship between social media exposure and risk perceptions. The findings of this study showed that social media exposure was positively related to forming risk perceptions. Moreover, heuristic-systematic processing and self-efficacy were found to moderate the impact of social media on risk perceptions. The interaction effects suggested that the role of social media in increasing risk perceptions of MERS was heighted by heuristic-systematic processing and self-efficacy. The results and implications of this study are discussed in greater details.

Preventive behavioral intentions a b s t r a c tIndividuals use social network sites (SNSs) as an effective tool for communicating relevant information with others during the outbreak of infectious diseases. However, little is known about the underlying mechanism through which communicative behaviors influence preventive behaviors. Thus, in the context of Middle East respiratory syndrome (MERS) in South Korea, this study investigated how two communicative behaviors (message expression and reception) in SNSs affected the communicators' intentions to engage in MERS-preventive behaviors. Using data collected from a nationally representative panel survey of 1000 Korean adults aged 19 or older, we examined a theoretical expression and reception effects model. Results support the presence of effects from expressing and receiving MERS-related information via SNSs and their underlying mechanism during South Korea's MERS outbreak. Public health officials and communication professionals should actively use SNS communication in coping with public health crisis caused by emerging infectious diseases.

This study examines the moderating role of emotional communication competence in the relationship between computer-mediated social support (CMSS) group participation, specifically giving and receiving emotional support, and psychological health outcomes. Data were collected as part of randomized clinical trials for women diagnosed with breast cancer within the last 2 months. Expression and reception of emotional support was assessed by tracking and coding the 18,064 messages that 236 patients posted and read in CMSS groups. The final data used in the analysis was created by merging (a) computer-aided content analysis of discussion posts, (b) action log data analysis of system usage, and (c) baseline and six-month surveys collected to assess change. Results of this study demonstrate that emotional communication competence moderates the effects of expression and reception of emotional support on psychological quality of life and breast cancer-related concerns in both desired and undesired ways. Giving and receiving emotional support in CMSS groups has positive effects on emotional well-being for breast cancer patients with higher emotional communication, while the same exchanges have detrimental impacts on emotional well-being for those with lower emotional communication competence. The theoretical and practical implications for future research are discussed.

Objectives-To examine the effects of exchanging treatment information within computermediated breast cancer support groups on emotional well-being, and to explore whether this relationship is moderated by health self-efficacy.Methods-Sample: 177 breast cancer patients using an electronic Health (eHealth) program with discussion group. Measure: expression and reception of treatment information; emotional wellbeing scale (0, 4 months). Analyses: hierarchical regression.Results-Effects of expression and reception of treatment information on emotional well-being were significantly greater for those who have higher health self-efficacy. Conclusions-Resultsconditionally support prior research finding positive effects of treatment information exchanges among breast cancer patients. Such exchanges had a positive impact on emotional well-being for those with higher health self-efficacy, but they had a negative influence for those with lower health self-efficacy.Practice implications-Given that the association between emotional well-being and exchanging treatment information was moderated by health self-efficacy, clinicians should explain the role of health self-efficacy before encouraging patients to use eHealth systems for treatment exchanges.

Social media have become increasingly important in risk and crisis situations. However, little is known about which types of social media have greater influence on risk perceptions and behaviors. This study pursues two goals related to this question. The first is to explicate the cognitive mechanism underlying the process through which exposure to risk information on social media shapes people's behavioral intentions. The second is to determine whether exposures to risk information on two different types of social media-content-oriented social media focusing on shared interests versus user-oriented social media focusing on social relationships-have different effects on people's risk perceptions and behavioral intentions. Analyzing survey data from 688 adults from the general population of South Korea in the context of carcinogenic hazards, we found that self-reported content-oriented social media exposure (to risk information) was significantly related to both personal-level and societal-level risk perceptions. In addition, content-oriented social media exposure was associated with behavioral intentions indirectly through risk perceptions. However, user-oriented social media exposure had no impact on risk perceptions and behavioral intentions, either directly or indirectly through risk perceptions.