*Literature Review*

Literature on social media analysis has been previously analyzed in di fferent applications that explore the pivotal role played by people's perspective and community interactions to obtain worthwhile information for healthcare decision-making [15]. Applications of social media analysis for collecting information on behavioral patterns have previously been proposed under di fferent conditions and with di fferent purposes. In cancer, for instance, content analysis of discussions related to medication use and side e ffects [16] showed how the internet can be a valuable way for individuals to report side e ffects, and how healthcare professionals can support an e ffective medication adherence plan by monitoring the social media discussion. Another example can be found in tweets about diabetes and diets [17], emphasizing how some users acting as diabetes advocates can spread information and serve as opinion leaders, thus influencing others' attitudes and behavior [18].

Other studies have reported the beneficial e ffects of higher patient satisfaction and patient engagemen<sup>t</sup> when hospitals create valuable social media interaction and strategy, providing better value for the hospitals adopting such a policies [19].

A recent literature review [20] that explored the e ffects of social media interaction on patient and healthcare professional relationships pointed out how patients mainly use social media for social support, which is represented through information support, emotional support, esteem support, and network support.

One of the main advantages of Twitter is the fact that users can express themselves freely, reducing the bias e ffect that often a ffects other types of investigation methods, such as online surveys or interviews [21]. On the other hand, it is important to consider the risks of using Twitter in social and healthcare research given the unrepresentativeness of the user community, the spread of misinformation, and di fficulties in verifying the credibility of sources.

However, we believe that perspectives and views held by community members and expressed on social media platforms represent a good proxy of feelings and attitudes that might influence decision-making of other communities or users. Identifying as precisely as possible the content of these feelings and attitudes would improve the development of a tailored strategy for public health issues.

Analyzing the network dynamics and the role played by key users in the network community (such as influencers and opinion leaders) o ffers a gatekeeping tool to understand how information enters, flows, and spreads throughout the communities, and who drives it.
