P2/N95 fit testing and the risk of COVID-19 in Healthcare Workers

BACKGROUND

Guidelines recommend healthcare workers (HCWs) undertake fit testing of P2/N95 respirators to mitigate the risk of infectious aerosols, however few studies have assessed whether fit testing reduces COVID-19 infection.

METHODS

A retrospective cohort study was conducted amongst HCWs across two tertiary health services in Melbourne, Australia during a period of low community transmission. Institution-wide quantitative fit testing and detailed questionnaires assessing COVID-19 acquisition risk factors were undertaken from September 2020. HCWs diagnosed with COVID-19 in the period prior to the fit testing program (February 1st - August 31st 2020) were matched on a 1:3 ratio to HCWs who had not been diagnosed with COVID-19. Risk factors for COVID-19 acquisition, including fit testing outcome, were compared between groups.

RESULTS

A total of 1571 HCWs took part in fit testing programs. Seventy-two (4.6%) were diagnosed with COVID-19 within the study period. Younger age, nursing staff, close contact with a COVID-19 case, and working longer periods in wards with COVID-19 patients, were associated with COVID-19 infection. After matching for intensity of occupational exposure to infectious aerosols, close contact was the only independent variable associated with COVID-19 infection (OR 3.50, 95% CI:1.65-7.44, p = 0.001). Adequate fit test for the respirator predominately worn before the fit testing period was not associated with COVID-19 (OR 1.08, 95% CI:0.59-1.98, p = 0.815).

CONCLUSION

After controlling for intensity of occupational exposure to infectious aerosols, P2/N95 respirator fit testing was not associated with reduced risk of COVID-19 infection. The utility of widespread fit testing to reduce HCW COVID-19 infections should be reconsidered.

The development and evaluation of a brief risk screening instrument for the psychiatric inpatient setting

This paper reports on the development and evaluation of a risk screening instrument (RSI) intended for use by nursing staff on general acute psychiatric admission wards. The RSI comprised six questions concerning patient status on admission (e.g. sex, legal status, employment) and 11 items of judgement concerning the presentation of the patient (e.g. threatening behaviour, suicidality, family and social support). The interrater reliability of the RSI was calculated to be 85% overall. The predictive value of the RSI was not confirmed when tested against harmful incidents subsequent to admission. However, the mean RSI score of that group of patients involved in harmful incidents tended to be higher than that group of patients not involved in such incidents, and all such incidents were found to occur within eight days of admission. Analysis of other data collected in the course of the study revealed discrete patient groups and provided systematic insights into their characteristics, which are potentially valuable when considering the nursing skills required on acute psychiatric inpatient units. It is concluded that the RSI tested has the potential to contribute to the assessment and management of risk within the acute psychiatric inpatient setting, by augmenting and guiding clinical judgement.