Decision Making ; Humans ; Models, Theoretical ; Public Health ; Risk Assessment

INTRODUCTIONThis study aimed to determine if disposable filtering facepiece respirators (FFRs) that come with an exhalation valve (EV) and a novel active venting system (AVS) provided greater perceived comfort and exertion when compared to standard N95 FFRs without these features among male military personnel performing prolonged essential outdoor duties.

METHODSWe used a randomised open-label controlled crossover study design to compare three FFR options: (a) standard FFR; (b) FFR with EV; and (c) FFR with EV+AVS. Male military personnel aged between 18 and 20 years completed a questionnaire at the start of outdoor duty (baseline), after two hours of standardised non-strenuous outdoor duty and after 12 hours of duty divided into two-hour work-rest cycles. Participants rated the degree of discomfort, exertion and symptoms using a five-point Likert scale. The association between outcomes and types of FFR was assessed using a multivariate ordered probit mixed-effects model.

RESULTSFor a majority of the symptoms, study participants gave FFR with EV and FFR EV+AVS significantly better scores than standard FFR. Both FFR with EV and FFR with EV+AVS had significantly less discomfort (FFR with EV+AVS: 91.1%; FFR with EV: 57.6%) and exertion (FFR with EV+AVS: 83.5%; FFR with EV: 34.4%) than standard FFR. FFR with EV+AVS also had significantly better scores for exertion (53.4%) and comfort (39.4%) when compared to FFR with EV.

CONCLUSIONUsage of FFR with EV+AVS resulted in significantly reduced symptoms, discomfort and exertion when compared to FFR with EV and standard FFR.