Figure 2.

The top example (A) is the original training example. It has 2 SDOH events, where the event triggers are “Tob” and “EtOH”. Example (B) is a derived example that covers the same events as (A) but with source text created according to the tight-text-bound. Example (C) is a derived example covering only the first event in (A). Example (D) is the tight-text-bound version of example (C). The final derived example (E) covers only the second event in (A), and the loose-text-bound version is equivalent to the tight-text-bound version. SDOH: social determinants of health.