Infodemics and Health Misinformation: A Systematic Review of Reviews

"...[M]ost systematic reviews evaluating the social-, economic- and health-related repercussions of misinformation on social media noted a negative effect....Furthermore, studies reported that social media has been increasingly propagating poor-quality, health-related information during pandemics, humanitarian crises and health emergencies."

Crises such as infectious disease outbreaks and disasters often spawn a torrent of online information containing either false and misleading information or accurate content - an infodemic - with negative social and health-related impacts. Several studies have analysed the effects of infodemics and misinformation and how societal behaviours are affected. This systematic review of reviews aims to collate, compare, and summarise the evidence from recent infodemics. To improve and guide infodemic management, the study identifies challenges, knowledge gaps, and opportunities in addressing the negative effects of the dissemination of health misinformation on public health.

The researchers searched MEDLINE®, Embase®, Cochrane Library of Systematic Reviews, Scopus, and Epistemonikos on May 6 2022 for systematic reviews analysing infodemics, misinformation, disinformation, and fake news related to health. They used the AMSTAR 2 approach to assess the reviews' methodological quality and the Grading of Recommendations Assessment, Development and Evaluation guidelines to evaluate the quality of the evidence.

The search identified 31 systematic reviews, of which 17 were published (between 2018 and 2022). Of the latter, 14 were published after the SARS-CoV-2 outbreak. The published reviews included 1,034 primary studies covering 12 infectious diseases and 3 major topics (vaccination hesitancy, disaster communication, and disease outbreaks). See Table 1 in the paper for a summary of the included reviews.

The main outcomes, categorised in six themes, are summarised in Box 2 and by study in Table 2; the article describes the outcomes, by theme, in more detail. In sum:

• Proportion of health misinformation on social media (4 studies):
  • Health misinformation in posts on social media is common (1-51% on posts associated with vaccine, 0.2-28.8% on posts associated with COVID-19, and 4-60% for other pandemics).
  • Approximately 20-30% of the YouTube videos about emerging infectious diseases contain inaccurate or misleading information.
• Source of health misinformation propagation (6 studies):
  • Social media platforms are associated as a potential source of promotion of anecdotal evidence, rumours, fake news, and general misinformation.
  • Twitter, Facebook, Instagram, and blogs play an important role in spreading rumours and speculating on health-related content during pandemics.
  • Digital influencers or well-positioned individuals act as distractors or judges in social networks.
  • Closed communication within online communities can be used to propagate and reverberate unreliable health information.
  • Misinformation can be derived from poor-quality scientific knowledge.
• Effects of infodemics, misinformation, disinformation, and fake news (10 studies):
  • Several of the consequences were linked to altering people's attitude towards the situation: (i) distorting the interpretation of scientific evidence; (ii) polarising opinions and having echo chamber effects (that is, the formation of groups of like-minded users framing and reinforcing a shared narrative); (iii) offering non-specialists' opinions to counter accurate information; (iv) promoting fear and panic; (v) increasing mental and physical fatigue of population; and (vi) decreasing credibility of circulating information on different platforms during unforeseen circumstances.
  • Social impacts include: (i) decreasing trust in governments and public health systems and in the government's response and accuracy of the official health messaging; (ii) amplifying and promoting discord to create a hostile political environment; (iii) increasing violence against ethnic and minority groups; and (iv) affecting the global economy.
  • Within the health system, infodemics could lead to: (i) misallocation of resources and increasing stress among medical providers; (ii) decreased access to health care; (iii) increased vaccine hesitancy and conspiracy beliefs; (iv) increased illegal promotion of the sale of controlled substances; and (v) delayed delivery of high-quality care and proper treatment to patients, which could further have a negative effect on public healthcare systems.
• Corrective interventions (4 studies):
  • Correcting misinformation delivered by health professionals is harder than doing so for information delivered by health agencies.
  • Misinformation corrected by experts is more effective than when corrected by non-experts.
  • The effectiveness of correcting misinformation using text or images is similar.
  • Using refutational messages, directing the user to evidence-based information platforms, and creating legislative councils to battle fake news and increase health literacy are shown to be effective countermeasures.
• Adequate use of social media (8 studies):
  • Social media platforms and traditional media might be useful during crisis communication and during emerging infectious disease pandemics, regardless of geographical setting.
  • Using social media properly (e.g., infosurveillance) can be highly functional in tracking disease outbreaks.
  • Social media can improve knowledge acquisition, awareness, compliance, and positive behaviour towards adherence to clinical infection protocols and behaviours.
• Overall quality of publications during infodemics (3 studies):
  • When appraised using the AMSTAR 2 critical domains, 16 reviews (94.1%) scored as having critically low quality across most major domains; despite this, there was "excessive and inordinate media attention given to these studies".
  • There is a substantial overlap of published studies addressing the same research questions during an infodemic.

In addition to the aforementioned quality issues, research challenges identified in the review include:

• The difficulty of characterising and evaluating the quality of the information on social media;
• The fact that new trends in personal content creation are constantly emerging, such as TikTok, which represent new challenges for regulation;
• The need to further understand the economic impact of misinformation, the difference in distribution of health misinformation in low- and high-income countries (LMICs), and the real impact of antivaccine activism groups.
• Inadequate orientation of the population and medical providers into wrong pharmacological and non-pharmacological interventions;
• Creation and use of reliable health-related information and scientific evidence considering real-time updates; and
• The requirement of decisive and pro-active actions from government authorities and social media developers to avoid the destruction of positive achievements that social media has already promoted.

Potential future research areas include:

• Future investigations should be performed to provide different aspects of the impact and reliability of SARS-CoV-2-related or any other health emergency information.
• There is a need to balance the gold standard systematic reviews with faster pragmatic studies.
• Studies need to evaluate effective methods to precisely combat the determinants of health misinformation during pandemics and subsequent infodemics across different social media platforms.
• Novel investigations could focus on creating a basis to conduct future studies (especially randomised trials) comparing the use of social media interventions with traditional methods in the dissemination of clinical practice guidelines.
• Future studies should assess the potential of social media use on the recovery and preparation phases of emergency events.
• Researchers could analyse communication patterns between citizens and frontline workers in the public health context, which may be useful to design counter-misinformation campaigns and awareness interventions.
• A multidisciplinary specialist team could analyse governmental and organisational interventions to control misinformation at the level of policies, regulatory mechanisms, and communication strategies.
• Studies should address the impact of fake news on social media and its influence on mental health and overall health.
• Future studies should examine how social media users process the emerging infectious diseases-related information they receive.
• Focus should be given to how users evaluate the validity and accuracy of such information and how they decide whether they will share the information with their social media contacts.
• Further interdisciplinary research should identify effective and tailored interventions to counter the spread of health-related misinformation online.

In conclusion: "Based on the available evidence, people are feeling mental, social, political and/or economic distress due to misleading and false health-related content on social media during pandemics, health emergencies and humanitarian crises. Although the literature exponentially increases during health emergencies, the quality of publications remains critically low. Future studies need improved study design and reporting. Local, national and international efforts should seek effective counteractive measures against the production of misinformative materials on social media. Future research should investigate the effectiveness and safety of computer-driven corrective and interventional measures against health misinformation, disinformation and fake news and tailor ways to share health-related content on social media platforms without distorted messaging."