Time to Next APE
In the PS-matched sample, all 48 of the encounters with follow-up data required new antimicrobial treatment and the median event time was 82 days. Figure 3 displays Kaplan-Meier plots for each group and we can see that steroid administration had a time-varying effect on next APE. To overcome this violation of the proportional hazard assumption, we created a Cox model censoring patients still at risk after 82 days, and another model including only patients still at risk beyond 82 days. The effect of steroid administration reduced the risk of APE for the first model (fully-adjusted HR=0.534, 95% CI: 0.208, 1.372, p-value=0.193; Table 3), while steroid use appeared to increase risk in the second model (HR=1.716, 95% CI: 0.431, 6.838, p-value=0.444). However, the results were not significant.