Simulated Workplace Protection Factors For Respirators With N95 Or Higher Filters For Health Care Providers In An Emergency Medical Centre: A Randomized Crossover Study

Introduction: Health care providers in emergency medical centres often encounter infected sources during medical procedures; these sources can generate droplets. Wearing respirators could help to protect against infection risk. However, to the best of our knowledge, no previous study has reported the efficacy of N95 or higher respirators for health care providers in emergency medical centres.Methods: A randomized, crossover study of 26 health care providers was conducted to examine the protective performance of respirators. Quantitative fit tests with three types of respirators (cup type, fold type without valve and fold type with valve) were performed using seven exercises. Primary outcomes were the fit factors. Secondary outcomes included the percentage of fit factors above 100 and respirator preference.Results: After excluding one participant, data for 25 participants were analysed. The fit factors and the percentage of fit factors above 100 were higher when participants wore a fold-type respirator (200 fit factors [38.6-200], 100% [0-100]) relative to those for the cup-type respirator (114.0 fit factors [16.0-185.2], 60% [0-100]) and valve-type respirator (84.9 fit factors [14.2-170.8], 23.8 % [0-100]) in normal respiration. There was no clear preference regarding the type of respirator.Conclusion: The type of respirator could influence protective performance for health care providers. Health care providers in emergency medical centres should be aware of and wear the type of respirator that is well-fitted for them in advance.