Training and Fit Testing of Health Care Personnel for Reusable Elastomeric Half-Mask Respirators Compared With Disposable N95 Respirators

Abstract

This study examines the feasibility of rapidly training and fit testing health care workers to use elastomeric half-mask respirators (EHMRs), widely used in construction and manufacturing, as an alternative to N95 respirators during periods of shortage.

The demand for disposable respiratory protective devices needed to protect health care personnel may exceed supply during large outbreaks of respiratory infectious diseases.^1,2 Concerns are growing over global shortages of respiratory protective devices during the novel coronavirus disease 2019 (COVID-19) pandemic.³ A reusable alternative to N95 respirators for which health care personnel can be rapidly assessed for fit (fit testing) and trained for use is needed. Elastomeric half-mask respirators (EHMRs), which provide the same level of respiratory protection as N95 respirators, are one alternative⁴ (eFigure in Supplement 1). These reusable respirators are used in construction and manufacturing, but not widely used in health care⁴ because of uncertainty about disinfection methods and upfront costs.⁵ The goal of this demonstration study was to test the feasibility of rapidly training and fit testing health care workers to EHMRs.

Methods

In 2019, 2 US health care organizations (Emory University and University of Texas Health [UTHealth] Science Center at Houston) conducted an outbreak simulation in which health care personnel, who were randomized to EHMR (80%) or N95 (20%) groups, were rapidly fit tested and trained. The institutional review boards at UTHealth, Baylor College of Medicine, and Emory University approved this study. Written informed consent was obtained at recruitment. Fit testing was performed to assess respirator fit to face, checking for leaks, using an Occupational Safety and Health Administration qualitative fit testing process.⁶ The number of fit testing attempts and testing time were recorded. Both groups were trained using a 9-minute video. The EHMR group was assessed 3 times consecutively for 26 performance indicators in the following 6 key areas: (1) inspection, (2) donning, (3) positive-pressure user seal check, (4) negative-pressure user seal check, (5) doffing, and (6) disinfection. Trainers scored participants based on the degree of assistance needed to complete each step (1 indicated physical assistance; 2, verbal assistance; 3, no assistance). A total score for each area consisted of a sum of 4 or 6 individual performance indicators (3 points each) ranging from 12 or 18, with a possible overall score of 78 points. Mean differences for time to completion of fit testing between groups was calculated using t tests, differences in the number of attempts to achieve proper fit were calculated using χ² tests, and ANOVA with post hoc and 2-sided pairwise comparisons were used to compare EHMR performance scores by attempts with α = .05. No sample size calculation was performed. Additional details are available in the protocol (Supplement 2). Analyses were conducted using SPSS, version 25.

Results

Of 193 health care personnel randomized, 153 (79%) participated in the study (124 in the EHMR group and 29 in the N95 group) (Table 1). The majority of participants were women (77%), with a mean age of 38 years. Overall, 87% of participants had at least 1 year of experience wearing a respiratory protective device; 9.7% of participants in the EHMR group vs 27.6% in the N95 group had no prior experience. Few participants (1.3%) had prior experience using an EHMR.

Table 1. Participant Demographic Characteristics, Respirator Wear Experience, and Fit Assessments in a Study Comparing Elastomeric Half-Mask Respirator and N95 Respirators (N = 153).

	Participants, %
	EHMR (n = 124)	N95 (n = 29)
Age, mean (SD), y	38.19 (11.19)	38.59 (10.65)
Sex
Men	21.0	34.5
Women	79.0	65.5
Occupation
Nurse	41.1	41.4
Physician/physician assistant/nurse practitioner	16.1	13.8
Respiratory therapist	12.9	24.1
Nurses’ aide/patient sitter	6.5	6.9
Social worker	7.3	0.0
Medical student	1.6	0.0
Other ancillary workers	14.5	13.8
Hospital unit
Medical/surgical units	25.8	13.8
Emergency department	21.8	13.8
Intensive care unit	26.6	37.9
All units (float)	10.5	10.3
Other units	7.3	20.7
Administrative	8.1	3.4
Type of respirator previously useda
None	9.7	27.6
EHMR	0.8	3.4
N95	88.7	69.0
PAPR	9.7	13.8
Years of experience wearing respirators
0	9.7	27.6
1-5	33.9	20.7
6-10	25.8	10.3
11-20	16.9	24.1
>20	13.7	17.2
Qualitative fit testing attempts to passb,c
1	92.2	88.5
2	6.1	7.7
3	1.7	3.9
Time to complete qualitative fit testing, mean (95% CI)c,d	6 min 47 s (6 min 26 s to 7 min 8 s)	6 min 29 s (5 min 46 s to 7 min 13 s)

Abbreviations: EHMR, elastomeric half-mask respirator; PAPR, powered air-purifying respirator.

^aNot mutually exclusive (could select more than 1 respirator type).

^bDifference in number of attempts to pass fit testing in the EHMR vs N95 groups: P = .76. Fisher exact was used to test collapsed categories (1, >1); P = .54.

^cExcluded 10 participants in the EHMR group and 3 in the N95 group because of missing time data.

^dMean difference in time between EHMR vs N95 group, 0 min 18 s (95% CI, −0 min 31 s to 1 min 6 s).

In the EHMR group, 92.2% passed fit testing during the first attempt compared with 88.5% in the N95 group (P = .76); all participants passed by the third attempt. The mean time to complete fit testing for the EHMR group, including total number of attempts (6 min 47 s), was not significantly different than the N95 group (6 min 29 s) (difference, 0 min 18 s [95% CI, −0 min 31 s to 1 min 6 s]; P = .48). Participants’ performance scores for EHMR use significantly improved from the first to second attempts overall and in all areas, with a significant improvement from the second to third attempt in 1 area (Table 2).

Table 2. Mean Elastomeric Half-Mask Respirator Performance Scores for 6 Key Areas and 26 Individual Indicators (N = 124) .

Performance area	Performance scorea,b
	Mean			Mean difference (95% CI)
	1st attempt	2nd attempt	3rd attempt	1st vs 2nd attempt	2nd vs 3rd attempt
Total performance score	72.0	76.4	77.4	−4.34 (−5.33 to −3.35)c	−1.01 (−2.00 to −0.02)c
Inspecting respirator	11.26	11.81	11.92	−0.54 (−0.75 to −0.33)c	−0.12 (−0.34 to 0.09)
Face piece	2.78	2.96	2.97
Head straps	2.89	2.98	2.98
Exhalation valve	2.77	2.93	2.99
Filters	2.82	2.94	2.98
Donning respirator	11.75	11.93	11.97	−0.18 (−0.28 to −0.07)c	−0.04 (−0.14 to 0.06)
Face piece	2.93	2.99	2.98
Head harness	2.98	3.00	3.00
Neck strap	2.98	2.98	3.00
Adjust straps	2.86	2.96	2.98
Positive-pressure user seal check	11.43	11.82	11.96	−0.40 (−0.57 to −0.22)c	−0.14 (−0.31 to 0.04)
Cover exhalation valve and exhale	2.90	2.95	3.00
Check for leaks	2.92	2.98	2.99
Readjust respirator	2.88	2.99	3.00
Repeat user seal check	2.73	2.90	2.97
Negative-pressure user seal check	11.62	11.88	11.95	−0.26 (−0.40 to −0.12)c	−0.07 (−0.21 to 0.07)
Palms over filter intakes and inhale	2.94	2.97	2.99
Check for slight face piece collapse	2.89	2.98	2.98
Readjust respirator	2.92	2.99	3.00
Repeat user seal check	2.87	2.94	2.98
Doffing respirator	10.47	11.44	11.79	−0.98 (−1.24 to −0.72)c	−0.34 (−0.61 to −0.86)c
Hand hygiene and gloves	2.40	2.66	2.88
Unhook neck strap	2.88	2.95	2.97
Remove without touching respirator face piece	2.51	2.91	2.98
Place on pad	2.69	2.92	2.97
Cleaning/disinfecting respirator	15.45	17.49	17.80	−2.04 (−2.4 to −1.6)c	−0.30 (−0.70 to 0.09)
Hand hygiene and gloves	2.73	2.94	2.98
Hold inside and wipe outside	2.44	2.91	2.98
Prepare clean pad or surface	2.47	2.91	2.95
Hand hygiene and gloves	2.67	2.91	2.95
Wipe inside of respirator	2.72	2.96	3.00
Remove gloves and hand hygiene	2.44	2.86	2.92

^aKey EHMR performance areas are the sum of individual indicators (3 points each), with total possible scores of 12 or 18.

^bIndividual indicator scores are degree of assistance needed to complete (1 indicates physical assistance; 2, verbal; 3, none).

^cMean differences (95% CI) between attempts (P < .05).

Discussion

This study found that health care personnel can be rapidly fit tested and trained to use the reusable EHMR. Time to achieve fit with EHMRs was not significantly different than with N95 respirators. High EHMR performance was demonstrated. EHMR participants had prior experience using other forms of respiratory protection, which may have influenced their high performance. Limitations include the simulated emergency, small number of participants, and lack of data on actual use of EHMRs. No information was available to inform sample size calculations; P values may not be meaningful. Better understanding about the efficacy and feasibility of disinfection methods are key. Combined with an Occupational Safety and Health Administration respiratory protection program,⁶ the EHMR may serve as a suitable alternative to disposable N95 respirators during public health emergencies.

Section Editor: Jody W. Zylke, MD, Deputy Editor.

Supplement 1.

Elastomeric Half-Mask Respirator and N95 Respirator

Supplement 2.

Study Protocol