Figure 5
From: Analysis of human immune responses in quasi-experimental settings: tutorial in biostatistics

Line graph of individual trajectories centered on the time of event reflects time elapsed between pre/post measurements. The measurements collected before an event are on left relative to a vertical dotted line and the post-event measurements are on right side. Thus, the negative values on a horizontal axis indicate the time of a surveillance sample taken before diarrheal episode and the positive values are times of surveillance sample since an episode. The summary statistics for measurement timing and shown in Table 2.