 This is a longitudinal, observational study of chronic wounds and ulcers treated at participating hospital based, outpatient wound centers. Data collection began in 2005. Structured data are collected at the point of care in the patient electronic health record and data from all patients at more than 100 wound centers in the USA and Puerto Rico are transmitted to the U.S. Wound Registry which is recognized by CMS as a Qualified Clinical Data Registry QCDR. Participation in the USWR can satisfy the registry participation option for Stage 2 of Meaningful use. The dataset includes all wound and ulcer types such as diabetic foot ulcers, venous stasis ulcers, pressure ulcers, arterial ulcers, surgical wounds, traumatic wounds, vasculitic ulcers, arterial ulcers, sickle cell ulcers, inflammatory ulcers e.g. pyoderma gangrenosum, and ulcers related to skin disorders such as scleroderma. Interventions provided include advanced dressings, compression bandaging, off-loading, cellular andor tissue based therapies, hyperbaric oxygen therapy, negative pressure wound therapy, debridement, and antibiotics. Ulcers are risk stratified for outcomes reporting using the Wound Healing Index.Outcomes measured include healing or wound closure, surgical closure, death, and major and minor amputation. Data on wound care specific quality measures developed by the QCDR are also available. 