CRP and infectious meningitis: Although both log2 CRP (odds ratio = 1.20; 95% CI, .97–1.49) and the high CrAg titer subgroup (odds ratio = 1.72; 95% CI, .73–3.99) were only modestly associated with the risk of meningitis or death in a multivariate logistic regression model (Figure 2), there was a significant interaction when both variables were combined with an interaction term between log2 CRP and CrAg titer group (P = .005).