Hospital-free Days as an Outcome Metric in Evaluating Outcomes After Ruptured Abdominal Aortic Aneurysm

Patient-centric outcomes have yet to be used for ruptured abdominal aortic aneurysm (RAAA) repair. Hospital-free days (HFD) describes the number of days alive outside of a hospital or emergency department (ED) following the index repair and is an emerging surrogate marker for functional independence which is more nuanced than mortality. We explored HFD as an outcome metric in patients with RAAA and determined factors associated with HFD. We synergized the Healthcare Cost and Utilization Project's Florida State Inpatient and ED Databases, allowing longitudinal hospitalization and ED visits follow-up. We included adults (>18 years) without connective tissue diseases, hospitalized with a primary diagnosis of RAAA (2015-2018), who underwent repair. The primary outcome was 90-day HFD (90HFD), and secondary outcomes included in-hospital mortality and discharge to home. t test and Wilcoxon rank-sum testing compared observed outcomes overall and in the subgroup who survived their index admission to discharge. Multivariable ordered logistic regression evaluated the association between patient and AAA repair variables and 90HFD. There were 503 patients with RAAA who received either endovascular (EVAR; n = 327 [65.0%]) or open (OAR; n = 176 [35.0%]) repair. The majority were male (n = 403 [79.5%]) with a mean age of 72.9 ± 10 years. In-hospital mortality was 27.8% overall and was lower for EVAR than OAR (22.0% vs 38.6%; P < .001). Among those who survived to discharge, 39.1% were discharged home, higher following EVAR (45.5% vs 24.1%; P < .001). The median overall 90HFD was 71.0 days (interquartile range [IQR], 0.0-83.0 days). Again, median 90HFD was greater for EVAR (78.0 days [IQR, 0.0-86.0 days) vs 21.5 days [IQR, 0.0-77.4 days]; P < .001). Among all who survived to discharge (72.2%), the overall median 90HFD was 80.0 days (IQR, 64.0-86.0 days) and again differed by repair type: 82.0 days (IQR, 71.0-87.0 days) for EVAR and 73.5 days (IQR, 33.0-81.5 days) for OAR (P < .001) (Figure). Upon modeling, OAR (adjusted odds ratio [aOR], 0.237; 95% CI, 0.165-0.339), increasing age (aOR, 0.961; 95% CI, 0.946-0.977), and chronic kidney disease stage 3 or above (aOR, 0.477; 95% CI, 0.316-0.721) were associated with lower 90HFD. HFD is a viable outcome measure for RAAA that allows for more nuanced and patient-centered evaluation than traditional mortality outcomes. Fewer 90HFD was associated with open repair, increasing age, and chronic renal insufficiency. This metric may help inform physician and patient decision-making.