Medicare-VHA dual use is associated with poorer chronic wound healing

Veterans who use Veterans Health Affairs (VHA) have the option of enrolling in and obtaining care from other non-VA sources. Dual system use may improve care by increasing options or it may result in poorer outcomes because of fragmented care. Our objective was to assess whether dual system use of VHA and Medicare for wound care was associated with chronic wound healing. We conducted a retrospective cohort study of 227 Medicare-enrolled VHA users in the Pacific Northwest who had an incident, chronic lower limb wound between October 1, 2006 and September 30, 2007 identified through VHA chart review. All wounds were followed until resolution or for up to one year. Dual system wound care was identified through Medicare claims during follow-up. We used a proportional hazards model to compare wound healing among VHA-exclusive and dual wound care users, using a time-varying measure of dual use and treating amputation and death as competing risks. About 18.1% of subjects were classified as dual wound care users during follow-up. After adjustment using propensity scores, dual use was associated with a significantly lower hazard of wound healing compared to VHA-exclusive use (HR = 0.63, 95%CI: 0.39-0.99, p = 0.047). Hazards for the competing risks, amputation (HR = 4.23, 95% CI: 1.61-11.15, p = 0.003) and death (HR = 3.08, 95%CI: 1.11-8.56, p = 0.031), were significantly higher for dual users compared to VHA-exclusive users. Results were similar in inverse probability of treatment weighted analyses and in sensitivity analyses that excluded veterans enrolled in a Medicare managed care plan and that used a revised wound resolution date based on Medicare claims data, but were not always statistically significant. Overall, dual wound care use was associated with substantially poorer wound healing compared to VHA-exclusive wound care use. VHA may need to design programs or policies that support and improve care coordination for veterans needing chronic wound care.