an assessment of the evidence - Council of Canadian Academies

40 Influenza Transmission and the Role of PPRE: An Assessment of the Evidencedecide on the distribution of respirators in the stockpile. For infrequent users, orthose who have not recently received training, re-training prior to use during apandemic will be needed. Both adequate training of individuals in assessing the fitof the respirator each time it is used, as well as qualitative or quantitative fit testingof individuals have been shown to improve facial fit. Most regulatory agencies andjurisdictions mandate that fit tests be conducted on an annual basis.Respirators are designed specifically to ensure capture of particles in the size rangethat can be inhaled into the respiratory tract, including the entire range referred toas “inhalable” which includes nasopharyngeal, tracheobronchial and alveolar-sizedparticles. A non-fit-tested respirator allows gaps between the PPRE and the user’sface that inhalable particles can easily pass through, thereby bypassing the filter.Clearly, this would compromise the ability of the respirator to serve as a PPRE.A recent publication by Duling et al. (2007) examined the level of protectionafforded by fit tested and non-fit-tested respirators. This study reported an assignedprotection factor (APF) of 4.6 when respirators that did not fit properly wereincluded in the dataset. The APF increased to about 10 when respirators that didnot pass qualitative fit tests were removed and the APF increased even further, to14.5, when respirators that did not pass the quantitative test were removed.User AdherenceA respirator cannot protect a wearer who does not know when to use it or how towear it. Recent studies carried out in Canada, the United States and the UnitedKingdom have shown that user compliance within institutional protocols for PPREis less than 100 per cent. Adherence is known to be associated with effective trainingprograms and with workplace safety climate. 16 Workers who have beenengaged in the planning steps of institutional protocols, and feel properly trainedin the use of their protective equipment, are far more likely to comply withinstitutional safety policies (Yassi, 2004; DeJoy, 1996).Comfort and PerformanceThe response of individuals to the use of respirators involves both physiologicaland psychological factors (Harber, 1988). The dominant physiological effect is theincrease in inspiratory resistance brought on by the airflow resistance provided bythe respirator. Relative to other types of respirators, the N95 particulate facepiece16 The safety culture is the organizational commitment to safety (policies, training, provision of PPE).The safety climate is the collective employee perception of that safety culture (Gershon, 2007; Yassi,2004). It is the safety climate that has been shown to be a far more reliable predictor of compliance.