Rapid antigen testing continues to be broadly recommended across the world for the prevention of transmission of SARS-CoV-2. We explore existing recommendations in the United States, evidence of decreasing diagnostic reliability of individual tests and potential benefits and harms of non-targeted testing. Recent research has found multiple commonly-used rapid antigen tests to now have diagnostic sensitivities below 30%, with sensitivities at or near 0% the first 48 hours of infection, using polymerase chain reaction (PCR) test positivity as the gold standard. Reliance on tests with low sensitivity could paradoxically increase transmission risk through false assurance. Furthermore, widespread testing has substantial direct and indirect costs, while its effectiveness for diminishing COVID-19 disease burden or improving overall community health is unclear. Because benefit has not been demonstrated with high-quality evidence, we argue against 1. The continued recommendations for and 2. Public funding of widespread community-based rapid antigen testing.

Clinical equipoise is characterized by genuine uncertainty within the medical community about the effectiveness of a medical intervention. Its existence is often deemed necessary for clinical trials and signals a need for higher quality evidence, most often with randomized controlled trials, before the intervention can be considered effective. A leading official of the United States Centers for Disease Control and Prevention Director, when testifying before Congress in February of 2023, indicated there was no need for randomized controlled trials of masking because, owing to overwhelming evidence of benefit, there was no longer equipoise about masking children for COVID-19. We disagree with this statement and outline the reasons why in this piece. We review the concept of clinical equipoise specifically using the example of child masking. We list reasons equipoise still exists for masking children, including a lack of consensus among experts, contradictory medical evidence and recent and ongoing randomized efforts. Finally, we differentiate between clinical equipoise and ethical appropriateness. Despite ongoing equipoise about masking children, we outline why, owing to lack of evidence of net benefit, recommending this intervention does not currently appear to be medically ethical.

We explore one systematic review and meta-analysis of both observational and randomized studies examining COVID-19 vaccines in 5- to 11-year-olds, which reported substantial benefits associated with vaccinating this age group. We discuss the limitations of the individual studies that were used to estimate vaccination benefits. The review included five observational studies that evaluated vaccine effectiveness (VE) against COVID-19 severe disease or hospitalization. All five studies failed to adequately assess differences in underlying health between vaccination groups. In terms of vaccination harms, looking only at the randomized studies, a significantly higher odds of adverse events was identified among the vaccinated compared with the unvaccinated. Observational studies are at risk of overestimating the effectiveness of vaccines against severe disease if healthy vaccinee bias is present. Falsification endpoints can provide valuable information about underlying healthy vaccinee bias. Studies that have not adequately ruled out bias due to better health among the vaccinated or more vaccinated should be viewed as unreliable for estimating the VE of COVID-19 vaccination against severe disease and mortality. Existing systematic reviews that include observational studies of the COVID-19 vaccine in children may have overstated or falsely inferred vaccine benefits due to unidentified or undisclosed healthy vaccinee bias.

OBJECTIVE: To determine the number of tweets discussing the risk of Mpox to children and young people in school and (1) determine accuracy, (2) for inaccurate tweets, determine if risk was minimised or exaggerated and (3) describe the characteristics of the accounts and tweets which contained accurate versus inaccurate information. DESIGN: Retrospective observational study. SETTING: Twitter advanced search in January 2023 of tweets spanning 18 May 2022-19 September 2022. PARTICIPANTS: Accounts labelled as: MD, DO, nurse, pharmacist, physical therapist, other healthcare provider, PhD, MPH, Ed. degree, JD, health/medicine/public policy reporter (including students or candidates) who tweeted about the risk of Mpox to children and young people in school. EXPOSURES: Tweets containing the keywords school and mpox, pox, or monkeypox from May to October 2022. MEASURES: (1) The total and ratio of accurate versus inaccurate tweets, the latter further subdivided by exaggerating or minimising risk, and stratified by account author credential type. (2) The total likes, retweets and follower counts by accurate versus inaccurate tweets, by month and account credentials. (3) Twitter user exposure to inaccurate versus accurate tweets was estimated. RESULTS: 262 tweets were identified. 215/262 (82%) were inaccurate and 215/215 (100%) of these exaggerated risks. 47/262 (18%) tweets were accurate. There were 163 (87%) unique authors of inaccurate tweets and 25 (13%) of accurate tweets. Among healthcare professionals, 86% (95/111) of tweets were inaccurate. Multiplying accuracy by followers and retweets, Twitter users were approximately 974× more likely to encounter inaccurate than accurate information. CONCLUSION: Credentialed Twitter users were 4.6 times more likely to tweet inaccurate than accurate messages. We also demonstrated how incorrect tweets can be quickly amplified by retweets and popular accounts. In the case of Mpox in children and young people, incorrect information always exaggerated risks.

Importance

Because the MMWR has substantial influence on United States public health policy and is not externally peer-reviewed, it is critical to understand the scientific process within the journal. Mask policies during COVID is one topic that has been highly influenced by data published in the MMWR.

Objective

To describe and evaluate the nature and methodology of the reports and appropriateness of conclusions in MMWR pertaining to masks.

Design, Setting and Participants

Retrospective cross-sectional study of MMWR publications pertaining to masks from 1978 to 2023.

Main outcome measures

Study date, design, disease focus, setting, population and location. Whether the study was able to assess mask effectiveness, if results were statistically significant, if masks were concluded to be effective, if randomized evidence and/or conflicting data was mentioned or cited, if causal statements were made about effectiveness, and, if so, whether they were appropriate.

Results

77 studies, all published after 2019, met our inclusion criteria. 75/77 (97.4%) studies were from the United States alone. All geographic regions and age groups were represented. The most common study design was observational without a comparator group 22/77 (28.6%). The most common setting was the community (35/77;45.5%). 0/77 were randomized studies. 23/77 (29.9%) assessed mask effectiveness, with 11/77 (14.3%) being statistically significant, but 58/77 (75.3%) stated masks were effective. Of these, 41/58 (70.7%) used causal language. Only one mannequin study used causal language appropriately (1.3%). 72/77 (93.5%) pertained to SARS-CoV-2 alone. None cited randomized data. 1/77 (1.3%) cited conflicting evidence.

Conclusions and Relevance

MMWR publications pertaining to masks drew positive conclusions about mask effectiveness over 75% of the time despite only 30% testing masks and <15% having statistically significant results. No studies were randomized, yet over half drew causal conclusions. The level of evidence generated was low and the conclusions drawn were most often unsupported by the data. Our findings raise concern about the reliability of the journal for informing health policy.