Categories based on recurrence of DUs within a 2-year observation period
| Category | Definition |
|---|---|
| No-DU | No DU at any FU visit |
| Episodic | Rarely recurrent: only 1 FU visit with either ≥1 DU or new DU; the remaining FU visits have no DU and no new DU |
| Recurrent | Frequently recurrent: ≥2 FU visits with DU and/or new DU, and ≥1 visit with no DU and no new DU |
| Chronic | ≥1 DU and/or new DU at every FU visit |
DU, digital ulcers; FU, follow-up.