DUs were assessed at each visit starting with the screening visit. Only DUs from the proximal interphalangeal joint (PIP) distally (both on the dorsal and volar surface of the hand, including the digital tip) were recorded. The location of each DU was noted. At each subsequent visit the location of each new DU was noted. DUs that occurred and healed between visits and were reported by patients were not recorded as new DUs. The evaluation was performed by an experienced physician or a trained rater with expertise in the assessment of DUs in systemic sclerosis (SSc). For a given patient, DUs were assessed by the same rater at each visit, whenever possible. Any DU that developed over a previously healed ulcer was recorded as a new DU. Incidence rate is adjusted for 16 weeks of observation, hence is calculated as the number of new DUs/total number of observation days.