Log in to MyACC
Association Between Universal Masking and SARS-CoV-2 Positivity
Quick Takes
- Universal masking at a large health care system in Massachusetts was associated with a significantly lower rate of SARS-CoV-2 positivity among health care workers (HCWs).
- This association may be related both to a decrease in transmission between patients and HCWs and among HCWs.
- Overall, these results support universal masking as part of a multifaceted strategy, along with social distancing measures and frequent handwashing, to minimize infection in health care settings.
Study Questions:
What is the association of hospital masking policies with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rate among health care workers (HCWs)?
Methods:
The investigators used electronic medical records and identified HCWs providing direct and indirect patient care who were tested for SARS-CoV-2 with reverse transcriptase–polymerase chain reaction. The authors identified three phases during the study period: a reintervention period before implementation of universal masking of HCWs (March 1-24, 2020); a transition period until implementation of universal masking of patients (March 25-April 5, 2020) plus an additional lag period to allow for manifestations of symptoms (April 6-10, 2020); and an intervention period (April 11-30, 2020). Positivity rates included the first positive test result for all HCWs in the numerator and HCWs who never tested positive plus those who tested positive that day in the denominator. Using weighted nonlinear regression, investigators fit the best curve for the reintervention and intervention periods (based on R2 value). The change in overall slope between the reintervention and intervention periods was compared to determine any statistically significant change in mean trend, using a two-sided α = .05.
Results:
Of 9,850 tested HCWs, 1,271 (12.9%) had positive results for SARS-CoV-2 (median age, 39 years; 73% female; 7.4% physicians or trainees, 26.5% nurses or physician assistants, 17.8% technologists or nursing support, and 48.3% other). During the reintervention period, the SARS-CoV-2 positivity rate increased exponentially from 0% to 21.32%, with a weighted mean increase of 1.16% per day and a case doubling time of 3.6 days (95% confidence interval [CI], 3.0-4.5 days). During the intervention period, the positivity rate decreased linearly from 14.65% to 11.46%, with a weighted mean decline of 0.49% per day and a net slope change of 1.65% (95% CI, 1.13%-2.15%; p < 0.001) more decline per day compared with the reintervention period.
Conclusions:
The authors concluded that universal masking was associated with a significantly lower rate of SARS-CoV-2 positivity among HCWs.
Perspective:
This cohort study reports that universal masking at a large health care system in Massachusetts was associated with a significantly lower rate of SARS-CoV-2 positivity among HCWs. This association may be related both to a decrease in transmission between patients and HCWs and among HCWs. Overall, these results support universal masking as part of a multifaceted strategy, along with social distancing measures and frequent handwashing, to minimize infection in health care settings. More broadly with emerging data on community benefits of face coverings, it is important that community and health care leaders ensure that everyone understands clearly when and how to wear cloth face coverings properly with consistent, clear messaging that makes community masking acceptable to prevent further spread of SARS-CoV-2 infection.
Clinical Topics: Cardiovascular Care Team, COVID-19 Hub, Prevention
Keywords: COVID-19, Electronic Health Records, Hand Disinfection, Health Personnel, Masks, Nurses, Patient Care, Physician Assistants, Primary Prevention, Reverse Transcriptase Polymerase Chain Reaction, SARS Virus, severe acute respiratory syndrome coronavirus 2, Psychological Distance
< Back to Listings
