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N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial

Author/s: 
Radonovich, LJ Jr, Simberkoff, MS, Bessesen, MT, Brown, AC, Cummings, DAT, Gaydos, CA, Los, JG, Krosche, AE, Gibert, CL, Gorse, GJ, Nyquist, AC, Reich, N.G., Rodriguez-Barradas, MC, Price, CS, Perl, TM, ResPECT investigators

IMPORTANCE:

Clinical studies have been inconclusive about the effectiveness of N95 respirators and medical masks in preventing health care personnel (HCP) from acquiring workplace viral respiratory infections.

OBJECTIVE:

To compare the effect of N95 respirators vs medical masks for prevention of influenza and other viral respiratory infections among HCP.

DESIGN, SETTING, AND PARTICIPANTS:

A cluster randomized pragmatic effectiveness study conducted at 137 outpatient study sites at 7 US medical centers between September 2011 and May 2015, with final follow-up in June 2016. Each year for 4 years, during the 12-week period of peak viral respiratory illness, pairs of outpatient sites (clusters) within each center were matched and randomly assigned to the N95 respirator or medical mask groups.

INTERVENTIONS:

Overall, 1993 participants in 189 clusters were randomly assigned to wear N95 respirators (2512 HCP-seasons of observation) and 2058 in 191 clusters were randomly assigned to wear medical masks (2668 HCP-seasons) when near patients with respiratory illness.

MAIN OUTCOMES AND MEASURES:

The primary outcome was the incidence of laboratory-confirmed influenza. Secondary outcomes included incidence of acute respiratory illness, laboratory-detected respiratory infections, laboratory-confirmed respiratory illness, and influenzalike illness. Adherence to interventions was assessed.

RESULTS:

Among 2862 randomized participants (mean [SD] age, 43 [11.5] years; 2369 [82.8%]) women), 2371 completed the study and accounted for 5180 HCP-seasons. There were 207 laboratory-confirmed influenza infection events (8.2% of HCP-seasons) in the N95 respirator group and 193 (7.2% of HCP-seasons) in the medical mask group (difference, 1.0%, [95% CI, -0.5% to 2.5%]; P = .18) (adjusted odds ratio [OR], 1.18 [95% CI, 0.95-1.45]). There were 1556 acute respiratory illness events in the respirator group vs 1711 in the mask group (difference, -21.9 per 1000 HCP-seasons [95% CI, -48.2 to 4.4]; P = .10); 679 laboratory-detected respiratory infections in the respirator group vs 745 in the mask group (difference, -8.9 per 1000 HCP-seasons, [95% CI, -33.3 to 15.4]; P = .47); 371 laboratory-confirmed respiratory illness events in the respirator group vs 417 in the mask group (difference, -8.6 per 1000 HCP-seasons [95% CI, -28.2 to 10.9]; P = .39); and 128 influenzalike illness events in the respirator group vs 166 in the mask group (difference, -11.3 per 1000 HCP-seasons [95% CI, -23.8 to 1.3]; P = .08). In the respirator group, 89.4% of participants reported "always" or "sometimes" wearing their assigned devices vs 90.2% in the mask group.

CONCLUSIONS AND RELEVANCE:

Among outpatient health care personnel, N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza.

TRIAL REGISTRATION:

ClinicalTrials.gov Identifier: NCT01249625.

Keywords 
respiratory disease respiratory infections N95 masks respirators flu influenza

Oseltamivir plus usual care versus usual care for influenza-like illness in primary care: an open-label, pragmatic, randomised controlled trial

Author/s: 
Butler, CC, van der Velden, AW, Bongard, E, Saville, BR, Holmes, J, Coenen, S, Cook, J, Francis, NA, Lewis, RJ, Godycki-Cwirko, M, Llor, C, Chlabicz, S, Lionis, C, Seifert, B, Sundvall, PD, Colliers, A, Aabenhus, R, Bjerrum, L, Jonassen Harbin, N, Lindbæk M, Glinz, D, Bucher, HC, Kovacs, B, Radzeviciene Jurgute, R, Touboul Lundgren, P, Little, P, Murphy, AW, De Sutter, A, Openshaw, P, de Jong, MD, Connor, JT, Matheeussen, V, Ieven, M, Goossens, H, Verheij, TJ

BACKGROUND:

Antivirals are infrequently prescribed in European primary care for influenza-like illness, mostly because of perceived ineffectiveness in real world primary care and because individuals who will especially benefit have not been identified in independent trials. We aimed to determine whether adding antiviral treatment to usual primary care for patients with influenza-like illness reduces time to recovery overall and in key subgroups.

METHODS:

We did an open-label, pragmatic, adaptive, randomised controlled trial of adding oseltamivir to usual care in patients aged 1 year and older presenting with influenza-like illness in primary care. The primary endpoint was time to recovery, defined as return to usual activities, with fever, headache, and muscle ache minor or absent. The trial was designed and powered to assess oseltamivir benefit overall and in 36 prespecified subgroups defined by age, comorbidity, previous symptom duration, and symptom severity, using a Bayesian piece-wise exponential primary analysis model. The trial is registered with the ISRCTN Registry, number ISRCTN 27908921.

FINDINGS:

Between Jan 15, 2016, and April 12, 2018, we recruited 3266 participants in 15 European countries during three seasonal influenza seasons, allocated 1629 to usual care plus oseltamivir and 1637 to usual care, and ascertained the primary outcome in 1533 (94%) and 1526 (93%). 1590 (52%) of 3059 participants had PCR-confirmed influenza infection. Time to recovery was shorter in participants randomly assigned to oseltamivir (hazard ratio 1·29, 95% Bayesian credible interval [BCrI] 1·20-1·39) overall and in 30 of the 36 prespecified subgroups, with estimated hazard ratios ranging from 1·13 to 1·72. The estimated absolute mean benefit from oseltamivir was 1·02 days (95% [BCrI] 0·74-1·31) overall, and in the prespecified subgroups, ranged from 0·70 (95% BCrI 0·30-1·20) in patients younger than 12 years, with less severe symptoms, no comorbidities, and shorter previous illness duration to 3·20 (95% BCrI 1·00-5·50) in patients aged 65 years or older who had more severe illness, comorbidities, and longer previous illness duration. Regarding harms, an increased burden of vomiting or nausea was observed in the oseltamivir group.

INTERPRETATION:

Primary care patients with influenza-like illness treated with oseltamivir recovered one day sooner on average than those managed by usual care alone. Older, sicker patients with comorbidities and longer previous symptom duration recovered 2-3 days sooner.

FUNDING:

European Commission's Seventh Framework Programme.

Keywords 
influenza flu Tamiful oseltamivir
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