Comparison of IFSG to SOC for treatment of venous leg ulcers using real-world data from the USWR with 1:1 matching on 14 wound/patient factors

BackgroundVenous leg ulcers (VLUs) impose substantial morbidity and Medicare spending, yet many real-world ulcers remain refractory to standard of care (SOC). Intact fish-skin graft (IFSG) is a biologic graft used for chronic wounds. We evaluated the comparative effectiveness of IFSG versus SOC in routine practice using a specialty wound registry with Real World Evidence design features intended to minimize bias. MethodsWe performed a retrospective, target-trial-emulating, 1:1 propensity score-matched comparative-effectiveness study within the U.S. Wound Registry (USWR). Matching used 14 prespecified patient- and wound-level covariates (including mobility as a measure of frailty and number of concomitant wounds). ResultsThe matched cohort included 129 IFSG-treated VLUs and 129 SOC-treated VLUs. Baseline balance was excellent by standardized mean differences. Small residual differences favored SOC; IFSG-treated wounds were older and trended larger. Healing occurred in 85.3% of IFSG-treated wounds (110/129) versus 75.2% of SOC-treated wounds (97/129); the absolute difference (+10.1%) was just below statistical significance (p=0.0801). SOC-treated VLUs increased in size on average more than IFSG-treated VLUs (p=0.0036). ConclusionsIn a national wound registry with rigorous cohort construction, aligned index timing, comprehensive covariate control, and structured outcome capture, IFSG demonstrated favorable real-world effectiveness versus SOC for VLUs with a trend towards more healed wounds and a statistically significant lower average wound expansion. The high healing rate in the SOC arm is plausibly explained by baseline advantages (shorter duration, smaller area, and "never-advanced-therapy" selection) as well as the absence of a set follow-up duration that typically extended until healing, a competing event, or administrative end of observation.