Fig. 3
![Fig. 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13075-017-1466-y/MediaObjects/13075_2017_1466_Fig3_HTML.gif)
Predicted time to first SIE, by baseline systemic glucocorticoid use and AACI. a RCT CZP. b All CZP. Predicted SIE-free survival curves correspond to Kaplan-Meier estimates for the indicated risk groups, based on the covariates selected by the Cox models. The c-indexes were 0.66 (95% CI 0.33–0.93) for the RCT CZP model and 0.85 (95% CI 0.73–0.93) for the All CZP model. aLow risk at baseline: AACI of 0, without systemic glucocorticoid use. bHigh risk at baseline: AACI ≥ 2, with systemic glucocorticoid use. SIE Serious infectious event, CZP Certolizumab pegol, AACI Age-adjusted comorbidity index, RCT CZP Patients randomized to CZP in the RAPID1/RAPID2 randomized controlled trials, All CZP All patients treated with CZP during the RAPID1/RAPID2 randomized controlled trials and/or open label extensions, CI Confidence interval