N95 respirators: quantitative fit test pass rates and usability and comfort assessment by health care workers

Abstract

Objectives: To compare the performance of four N95 respirator types with respect to quantitative fit test pass rate and health care worker-rated usability and comfort. Design, setting, participants: Health care workers who participated in the respiratory protection program at the Royal Melbourne Hospital, 1 October 2020 – 31 May 2021. Participants underwent quantitative N95 respirator fit testing (at least three of four types: semi-rigid cup, flat-fold cup, duckbill, and three-panel flat-fold types), and were invited to complete an online usability and comfort assessment for respirators for which their fit test results were passes. Main outcome measures: Fit test pass rate, and user-rated overall comfort and assessment ratings (five-point Likert scales), by N95 respirator type. Results: A total of 2161 health care workers underwent quantitative fit testing (women, 1586 [73.4%]; nurses, 1271 [58.8%]). The overall fit test pass rates were 65.0% for the semi-rigid cup respirators (1029/1583 tests), 32.4% for the flat-fold respirator (660/2035 tests), 59.2% for the duckbill respirators (2005/3387 tests), and 96.4% for the three-panel flat-fold respirator (1876/1946 tests). 378 health care workers completed the comfort and usability survey. Overall comfort and assessment ratings each differed by respirator group (P < 0.001); the median overall comfort (4; IQR, 3–4) and overall assessment values (4; IQR, 3–5) were highest for the three-panel flat-fold respirator and lowest for the semi-rigid cup respirators (comfort: 2 [IQR, 1–3]; assessment: 2 [IQR, 2–3]). Conclusions: The three-panel flat-fold N95 respirator outperformed the three alternative types with regard to fit test pass rate and user-rated comfort and usability. To maximise respiratory protection for health care workers, these factors should be considered when making respirator procurement decisions.