Table 2 Predictors of incidence of Hospital-acquired Viral Respiratory Infections (HA-VRI). The outcome variable was the HA-VRI incidence per 1000 hospital-days, aggregated by ward and year. The analysis was performed on 243 ward-years. Individual variables (mean age, gender, length of stay), structural factors (percentage of single occupancy rooms) and annual infection control indicators (hand hygiene, mask use) in each ward and year of sampling were included in the model as fixed effects. Hospital ward was included as random effect. The model was weighted by annual ward activity. For each one-unit increase or decrease in the explanatory variable, the outcome (HA-VRI incidence expressed for 1000 hospital-days) increases or decreases by a factor indicated by the beta coefficient. For reference, the average incidence of HA-VRI was 0.57/1000 hospital-days. Of note, estimated effects report associations rather than causality, meaning that these predictors do not necessarily cause variations of HA-VRI incidence (see discussion section)

From: Associations between hospital structure, infection control and incidence of hospital-acquired viral respiratory infections: a 10-year surveillance study