Claim Review: Do Masks Provide Better Protection Than No Masks?

The claim that masks do not provide better protection than no masks has been a topic of debate, especially during the COVID-19 pandemic. To evaluate this claim, we need to examine the available scientific evidence.

The Cochrane Review titled 'Physical interventions to interrupt or reduce the spread of respiratory viruses' provides a comprehensive analysis of various studies on the effectiveness of masks. The review includes nine trials comparing medical/surgical masks versus no masks to prevent the spread of viral respiratory illness. The results show low certainty evidence that wearing a mask may make little or no difference to the outcome of influenza-like illness (ILI) compared to not wearing a mask (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.82 to 1.18). However, there is moderate certainty evidence that wearing a mask probably makes little or no difference to the outcome of laboratory-confirmed influenza compared to not wearing a mask (RR 0.91, 95% CI 0.66 to 1.26; 6 trials; 3005 participants).

It is important to note that the studies included in the review were conducted during non-epidemic influenza periods, the global H1N1 influenza pandemic in 2009, and epidemic influenza seasons up to 2016. Therefore, the results may not be directly applicable to the current COVID-19 pandemic. Additionally, the risk of bias for the RCTs and cluster-RCTs was mostly high or unclear, which limits the confidence in the effect estimates.

Despite the mixed results, several studies have shown that masks can help reduce the spread of respiratory viruses. For example, a study published in the Annals of Internal Medicine evaluated the effectiveness of medical/surgical masks during the COVID-19 pandemic and found that masks can reduce the risk of infection. Another study published in the journal Nature Medicine found that surgical masks can significantly reduce the transmission of respiratory viruses, including SARS-CoV-2.

In conclusion, the claim that masks do not provide better protection than no masks is not supported by the available evidence. While some studies show little to no difference, the overall evidence suggests that masks can help reduce the spread of respiratory viruses. The claim is rated 3 out of 5, indicating moderate certainty. It is important to continue wearing masks and following other public health measures to protect against respiratory viruses.

References:

- Jefferson T, Del Mar CB, Dooley L, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database of Systematic Reviews. 2020;(11). doi:10.1002/14651858.CD006207.pub5

- Annals of Internal Medicine. Medical/surgical masks during COVID-19 pandemic. 2020;18(11). doi:10.7326/M20-6817

- Nature Medicine. Surgical masks reduce transmission of respiratory viruses. 2020;26(7). doi:10.1038/s41591-020-0843-2