FIGURE 1.

Directed acyclic graph showing the relationship between current influenza vaccination and medically attended influenza infection. Exposure and arrows pointing toward the exposure are shown in green, outcome and arrows pointing toward the outcome in orange, other variables and arrows in blue. Adapted from Lane et al. ⁶ * indicates the variable was not included in the DAG by Lane et al. † Healthcare seeking behavior: In addition to whether or not an individual seeks care, the timing of care seeking is important and applying time‐related restriction factors (regarding too long interval since symptom onset, too short interval since vaccination, and presentation when influenza is not circulating) is recommended. DAG, directed acyclic graph