NATIONWIDE - A new Danish study about face coverings is sparking discussion on social media and casting doubt on the effectiveness of mask wearing, although health experts refute the study as poor.

What You Need To Know

  • NASA's 1st Commercial Crew Mission to ISSUSF Health expert refutes Danish study casting doubt on mask wearing

  • Study was limited in scope, says Dr. Tom Unnasch

  • Mask mandate in Hillsborough County showed decline in COVID-19 cases while in place

  • BELOW: Hillsborough County cases graphic

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The study published in the Annals of Internal Medicine said masks did not reduce the COVID-19 infection rate among wearers by more than 50% in a community with modest infection rates.

USF's Dr. Tom Unnasch from the Center for Global Health Infectious Disease Research told Spectrum Bay News 9 it's a poor study.

Dr. Unnasch said the authors themselves admitted the limited investigation.

He pointed to some of the flaws in the research.

The study was underpowered; this means researchers did not have enough observations of cases.

The participants were asked to self-report their usage, with less than half fully complying. 

The study says masks protects others better than the person wearing them.

But this previous conclusion has been known for some time, which is why everyone should mask to protect each other.

Dr. Unnasch also said the study was done during some degree of lockdowns and social distancing in place. He offered local data to show the effectiveness of mask wearing in Hillsborough County (see below).

Because of the delay from when you get infected until when you become test positive, there's a lag in the effect of the mask mandate.

It was implemented in late June, two weeks later in July cases flattened. Then, the subsequent drop while the county remained in a mask ordinance.