Dual Use and Hospital Admissions among Veterans Enrolled in the VA's Homeless Patient Aligned Care Team.

Objective To examine the association between reliance on VA outpatient care and hospital admissions among Medicare-eligible Veterans enrolled in the Homeless Patient Aligned Care Team (H-PACT). Data Sources/Study Setting Registry of H-PACT enrollees linked to VA and Medicare utilization data for 2013. Study Design After assigning Veterans to two groups according to whether they received >90 percent of outpatient care in VA (higher reliance) or VA (lower reliance), generalized linear models with inverse probability of treatment weights were used to estimate the association of reliance with Medicare and VA-financed hospital admissions. Principal Findings Compared with higher reliance Veterans, lower reliance Veterans had an equivalent number of annual VA hospitalizations (0.63 vs. 0.50; p = .14) but substantially greater Medicare hospitalizations (0.85 vs. 0.08; p < .001). Among Veterans in the highest tertile of outpatient visits, we observed statistically similar rates of VA hospital use but over 10-fold greater rates of Medicare-financed hospitalizations (1.31 for lower reliance vs. 0.15 for high reliance; p < .001). Conclusions Among Veterans receiving integrated care in VA's H-PACT, dual use of Medicare and VA outpatient care is strongly associated with acute hospitalizations financed by Medicare. Linking VA and non-VA data may identify a subset of homeless Veterans with fragmented outpatient care who are at increased risk of poor outcomes.