Shigayeva 2007

Methods	Retrospective cohort study
Participants	HCW who provided care or entered the room of a Toronto SARS patient who required intubation during the 24 hours before and 4 hours after intubation. Eligible N = 879, Analysed N = 795; age (median) = 41 years (range 21 to 67 years); employment in current occupation (median) = 12 years (range 0 to 43 years); 46% nurses, 14% physicians, 14% respiratory therapists, 10% imaging staff and 16% other; 1055 exposure episodes or shifts. Intervention Active training: N = 511 episodes (= 385 persons), Intervention Passive training: N = 236 episodes (= 178 persons), Comparison no active training: N = 308 episodes (= 323 persons). Location: Canada
Interventions	Intervention 1: Active training: participants answered that they had received any individual or group face-to-face training sessions Intervention 2: Passive training: participants watched a video or got written information. Comparison: no training reported Other predictors of PPE studied in a multivariate GEE logistic regression analysis in addition to training for both outcomes: phase of epidemic, occupation, work experience, hospital type, location of care, number of times patienťs room entered, SARS diagnosis recognised, Apache II score of patient.
Outcomes	1. Consistent adherences as proportion of exposure episodes. Participants were interviewed based on a questionnaire 0.2 to 10 months after the exposure. Interviewers asked about consistent use of PPE: masks, gowns, gloves and eye protection and possible predictors of their use, including training. Consistent adherence was defined as always wearing gloves, a gown, a mask, and eye protection. Consistent adherence was reported in 817/1055 (77%) exposure episodes. Eye protection was least with 13.5% consistent and no PPE in 23 episodes (2.2%). PPE use increased during epidemic from 34.6% at start to 97.4% in the end. 2. Doffing as proportion of exposure episodes (safe, at some risk, or at risk). Participants were asked about their sequence of doffing PPE. Safe was defined as the sequence of removing gown and gloves, hand hygiene, mask, goggles, or safety glasses, hand hygiene. At some risk was considered if hand hygiene was performed only once. At risk if no hand hygiene was performed or hands touched potentially contaminated face. Doffing description was available for 810/1055 (77%) of exposure episodes; 15.4% qualified as safe, 63% as at some risk, and 22% as at risk.
Notes	Units of analysis used in studies: exposure episodes not persons exposed, based on work schedules, patient assignments and health records. There were 65 intubations of SARS patients of which 7 were not recognised as such at the time of intubation. Funding Ontario Ministery of Health and Long term Care; no Conflict of Interest reported
Risk of bias
Bias	Authors’ judgement	Support for judgement
Confounding NRS	Low risk	Adjustment in multiple regression analysis for education, work experience, and presumably for age and sex
Selection Bias NRS	Low risk	Whole cohort assessed that was working during the epidemic. Exposure to SARS patients clearly defined
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Both the intervention and the outcome were assessed at the same time
Blinding of outcome assessment (detection bias) All outcomes	High risk	Both the intervention and the outcome were assessed with the same questionnaire at the same time
Incomplete outcome data (attrition bias) All outcomes	Low risk	90% HCW participated for adherence and for 77% of shifts more or less reliable info about doffing available
Selective reporting (reporting bias)	Unclear risk	Not clear which predictors of adherence or safe doffing were tested and negative
Other bias	Low risk	No indication of other bias