3 ms·

Please. Table 6. Intervention: Wearing N95 Mask Intervention Effectiveness: 91%. It's true that handwashing, wearing some kind of mask, gloves, and gown comb

Please. Table 6. Intervention: Wearing N95 Mask Intervention Effectiveness: 91%. It's true that handwashing, wearing some kind of mask, gloves, and gown combined is also 91%, but that was not a study arm that specified an N95 mask. Wearing any mask has an intervention effectiveness of 68%. Adding the gloves and gown brings it up to 91%. What the meta-analysis is saying is that wearing any mask + gloves + gown + handwashing is about the same effectiveness as wearing just an N95 mask. It also supports the idea that "don't touch your face" is probably good advice, but it's also probably not the primary means that SARS spreads. It's probably mostly breathing in droplets that someone just exhaled. I understood perfectly well what they wrote. They say that evidence is limited for the superior effectiveness of N95 over any mask because the lower confidence interval of N95 and the upper confidence interval of any mask overlap by 5%. Based on the studies they analyzed though, it's likely that N95 is more effective than masks generally. It's also very logical since N95 masks filter better and have less leakage than surgical masks. I am tired of people like you trying to bend science to their ideology. That is part of what got us into this horrible mess.

presto8 7y ago
Table 6 for the N95 mask row cites w45 and w47. w47 had only 13 people in the study. And both w45 and w47 cite a medium risk of bias noting lack of description of controls and inconsistencies. It would be nice to have more rigorous studies to support the claim? Just to be clear, I do think people should wear masks! Seto 2003w47 13 healthcare workers infected with confirmed SARS within 2-7 days of exposure, with no community exposure w45 330 probable cases of SARS reported to Department of Health, Hong Kong
timr 7y ago
"Intervention: Wearing N95 Mask Intervention Effectiveness: 91%" I addressed this in my reply: this was based on two studies, both about transmission of the virus to other people. Moreover, the people doing the meta-analysis explicitly say that the evidence for using an N95 mask over a plain-old surgical mask is weak. The confidence interval extends from 0.03 to 0.30...in other words, the evidence is weak. So basically, this study supports the CDC's guidelines: masks might help prevent you from spreading your infection to others. They don't support your claim ("wearing an N95 mask reduces your chances of contracting SARS by 91%") in any way. "What the meta-analysis is saying is that wearing any mask + gloves + gown + handwashing is about the same effectiveness as wearing just an N95 mask." It is absolutely not saying this. It is saying that the combined intervention is dramatically more effective than wearing a mask alone, except for two studies that explicitly talk about transmission. You don't understand what you're reading, and you're spreading misinformation.

presto8 7y ago

Table 6 for the N95 mask row cites w45 and w47. w47 had only 13 people in the study. And both w45 and w47 cite a medium risk of bias noting lack of description of controls and inconsistencies. It would be nice to have more rigorous studies to support the claim? Just to be clear, I do think people should wear masks! Seto 2003w47 13 healthcare workers infected with confirmed SARS within 2-7 days of exposure, with no community exposure w45 330 probable cases of SARS reported to Department of Health, Hong Kong

timr 7y ago

"Intervention: Wearing N95 Mask Intervention Effectiveness: 91%" I addressed this in my reply: this was based on two studies, both about transmission of the virus to other people. Moreover, the people doing the meta-analysis explicitly say that the evidence for using an N95 mask over a plain-old surgical mask is weak. The confidence interval extends from 0.03 to 0.30...in other words, the evidence is weak. So basically, this study supports the CDC's guidelines: masks might help prevent you from spreading your infection to others. They don't support your claim ("wearing an N95 mask reduces your chances of contracting SARS by 91%") in any way. "What the meta-analysis is saying is that wearing any mask + gloves + gown + handwashing is about the same effectiveness as wearing just an N95 mask." It is absolutely not saying this. It is saying that the combined intervention is dramatically more effective than wearing a mask alone, except for two studies that explicitly talk about transmission. You don't understand what you're reading, and you're spreading misinformation.