Baseline characteristics of the patient population after multiple imputation of missing values and univariate association between variables and the risk of drain-related meningitis.

*: p-value using χ2, student's t or Mann-Whitney U test where appropriate.Abbreviations: DRM – drain-related meningitis; IQR –interquartile range; ICU – intensive care unit; CSF - cerebrospinal fluid; EVD – external ventricular drain; HAI – Healthcare-associated infection; SAH – subarachnoid hemorrhage; IVH – intraventricular hemorrhage.Number of missing values prior to imputation: Other HAI – 37.2%; CRP – 11.2%; Leukocytes (blood) – 8.4%; Hemoglobin – 6.1%; Thrombocytes – 11.2%; CSF leukocytes – 29.2%; CSF erythrocytes 29.1%; CSF glucose 30.7%; CSF protein 29.2%; Culture (CSF and/or drain) – 19.9%. All others: no missing values.