Further evidence no difference between N95 respirator and medical mask for influenza prevention

Reference

Radonovich LJ, Simberkoff MS, Bessesen MT, et al. N95 respirators vs medical masks for preventing influenza among health care personnel. A randomized clinical trial. JAMA 2019;322(9):824-33.

Synopsis

Many health care organizations continue to recommend the N95 respirator over the standard medical mask to prevent transmission of respiratory infections. These investigators identified health care personnel (n = 2862), aged 18 years or older, from diverse outpatient settings serving adult and pediatric patients with a high prevalence of acute respiratory illness. Participants randomly received assignment (allocation concealed) to wear a N95 respirator or standard medical/surgical mask whenever they were positioned with 6 feet (1.83 m) of patients with suspected or confirmed respiratory illness. Study personnel masked to treatment group assignment obtained swabs of the anterior nares and oropharynx from participants self-reporting symptoms of respiratory illness. In addition, random swabs were obtained from all participants, usually while asymptomatic. Paired serum samples were also obtained yearly from all participants during the peak influenza season. The primary outcome was laboratory-confirmed influenza from either a swab or serum seroconversion during 4 separate seasons of follow-up. Using intention-to-treat analysis, the incidence of laboratory-confirmed influenza was not significantly different between the N95 respirator group and medical mask group (8.2% vs 7.2%). Likewise, there were no significant differences in the incidence of any acute respiratory illness events.