Multistate Model of Chronic Wounds, Amputations, and Mortality: Cohort Study of a State-wide Registry

Use a new patient registry to characterize and predict progression of lower-extremity chronic wounds to amputation and/or death, while considering infection history.

Chronic wounds are a common health issue causing amputation and death. The Regenstrief Chronic Wound Registry, created from one of the U.S.'s largest health information exchanges, can give insights into their epidemiology.

This retrospective cohort study analyzed 52,916 patients first diagnosed with lower-extremity chronic wounds during 2011-2021, sourced from the registry of 152,237 chronic wound patients. Disease progression was modeled using a multistate model, tracking transitions from initial diagnosis to minor amputation, major amputation, and/or death. Cox proportional-hazards models assessed associations between time-dependent covariates, including infection history and wound type, and each state transition.

Three-year pooled mortality rates after wound diagnosis, minor amputation, and major amputation were 10.71%, 13.38%, and 19.47%, respectively. The multistate model showed these associations: diabetic foot ulcer and increased minor amputation; venous ulcer and decreased amputation or death; pressure ulcer, decreased minor amputation, and increased death; osteomyelitis, increased amputation, and decreased death before major amputation; sepsis and increased death before major amputation. Simulated patients' individualized risks were estimated-e.g., probabilities of major amputation for diabetic White patients within three years after minor amputation, with and without prior osteomyelitis diagnosis, were 3.7% and 14.9% respectively.

A multistate model, applied to a state-wide chronic wound patient registry, reveals insights into chronic wound disease progression, enables personalized prognoses for patients with chronic wounds, and has the potential to improve clinical decision-making.