Model update results for 2004–2011 data, including baseline characteristics and results of univariable and multivariable analysis.

a: p-value in univariable analysis by student's t test, Mann-Whitney U test or Chi-square where appropriate. b: Results of the multivariable analysis are after bootstrapping (shrinkage factor 0.79). The intercept of the model was estimated at –6.615. c: In the multivariable analysis, all CRP values were divided by factor 10. d: In the multivariable analysis, CSF leukocytes were log transformed. e: Culture results corrected for contamination with skin flora; if no antibiotics were started, culture was classified as negative. Abbreviations: CRP – C-reactive protein; CSF – cerebrospinal fluid; DRM – Drain-related meningitis; EVD – external ventricular drain; OR – Odd's ratio.