Temporal effects of educational interventions on fit and knowledge retention of N95 filtering facepiece respirator under rest and exertion

Introduction: Proper use of N95 filtering facepiece respirators is critical for respiratory protection in healthcare settings. Effective protection depends not only on respirator selection but also on adequate training and proper fit. Although text-based, video-based, and person-guided training approaches are commonly used, evidence comparing their effectiveness and the durability of training effects on quantitative fit performance and respirator-related knowledge remains limited, particularly among medical and nursing students. This study aimed to evaluate the effects of different training approaches on knowledge acquisition and respirator fit over time. Methods: This prospective study enrolled 42 participants who were randomly assigned to 3 training groups. Fit factor values were assessed using quantitative fit testing to evaluate changes in respirator fit over time, including immediately after training, at 2 wk, and at 3 mo. A questionnaire assessed participants' respirator-related knowledge and procedural competence in donning and doffing. In addition, a treadmill was used to standardize walking speeds of 1.5 and 3.0 miles/h to introduce controlled levels of physical activity. Results: The mean age of participants was 20.3 ± 2.2 yrs. Only 11.9% had prior experience with N95 respirators, and none had received formal training. The mean questionnaire accuracy increased significantly from 46.0 ± 11.9% at baseline to 65.9 ± 13.5% immediately after training (P < 0.01), but declined over time to 59.2 ± 15.3% at 2 wk (P < 0.05) and 54.9 ± 13.4% at 3 mo (P < 0.01). However, no significant differences were observed among training groups when analyzed by domain (knowledge and respirator-wearing practices). Median fit factor increased from 28 ((interquartile range, IQR) 7 to 99) at baseline to 143.5 (IQR 73.5 to 232.8) immediately after training, then declined to 130 (IQR 70 to 158) at 2 wk and 126 (IQR 92 to 195) at 3 mo (P < 0.001). Notably, the fit factor in the video- and guided-training groups remained significantly higher than that of the text group even after 3 mo (P = 0.029). Moreover, fit factor declined while respiratory rate and heart rate increased during treadmill walking rate at speeds of 1.5 and 3 miles/h (P < 0.001). Conclusion: Educational interventions both improve knowledge and respirator fit; however, these effects diminish over time, indicating the need for periodic reinforcement. Video-based and person-guided training offer superior retention of respirator fit performance at 3 mo compared to text-based instruction. Physical exertion may compromise respirator fit, emphasizing the need for awareness of potential fit limitations during clinical activities.