CDC Unmasked
Last year the CDC used a widely criticized study to recommend that children continue to wear masks in school.
Now, the University of Toronto has shown that the study that the CDC used was indeed flawed because of the limited abound of data used and it’s lack of inclusion of important variables.
The University of Toronto replicated the CDC study but with a much larger and more meaningful data set. The results? No significant relationship between mask mandates and case rates. These results persisted when using regression methods to control for differences across districts.
“School districts that choose to mandate masks are likely to be systematically different from those that do not in multiple, often unobserved, ways. We failed to establish a relationship between school masking and pediatric cases using the same methods but a larger, more nationally diverse population over a longer interval. Our study demonstrates that observational studies of interventions with small to moderate effect sizes are prone to bias caused by selection and omitted variables”