Fig. 4From: Healthcare institutions’ recommendation regarding the use of FFP-2 masks and SARS-CoV-2 seropositivity among healthcare workers: a multicenter longitudinal cohort studyRisk factors associated with SARS-CoV-2 seroconversion (multivariate model) at follow-up. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) as well as p values (Wald tests) derived from a logistic mixed-effects model for seroconversion at survey 2 (n = 2139)Back to article page