Predictors of Unplanned 30 Day Readmission in Diabetic Foot Wounds
Courtenay M. Holscher, MD, Joseph K. Canner, MHS, Ronald L. Sherman, DPM MBA, Kathryn Hines, PA-C, Mahmoud B. Malas, MD MHS, James H. Black, III, MD, Nestoras Mathioudakis, MD MHS, Christopher J. Abularrage, MD.
Johns Hopkins, Baltimore, MD, USA.
OBJECTIVE - The Center for Medicare and Medicaid Services (CMS) uses rates of unplanned 30-day readmission as a quality measure to penalize hospitals for readmissions. While there is recognition of high readmission rates for diabetic foot wounds, little is known about patient-level risk factors. The goal of this study was to identify factors associated with unplanned readmission in patients enrolled in a multidisciplinary diabetic foot service.
METHODS - We studied a single-center cohort of patients in a multidisciplinary diabetic foot service since July 2012. For those with multiple wounds, the overall highest SVS WIfI staged wound was selected for analysis. Predictors of unplanned 30-day readmission were analyzed with chi-square and t-tests.
RESULTS - Over the study period, there were 336 admissions in 170 patients. The average age was 58±12 years and the majority were male (63%) and black (64%). 50% were insured by Medicare, 26% had Medicaid, and 22% had private insurance. 441 podiatric and 83 vascular surgeries (45 open and 37 endo) were performed. Of the 336 admissions, there were 62 (18%) unplanned 30-day readmissions. The average length of stay (LOS) for the initial admission was 9±8 days while the average unplanned readmission LOS was 8±8 days. The most common reasons for unplanned readmission were related to foot wound (34%), gastrointestinal (12%), surgical bypass wound (9%), and renal (7%) complications. Unplanned readmissions were not predicted by any demographic or socioeconomic variable. Unplanned readmissions were more likely in patients with arterial insufficiency (P=.04), worse University of Texas (UT) stage (P=.03), and higher SVS WIfI composite scores (P=.04; Table). There were lower wound healing rates in those with an unplanned readmission (48 vs. 68%, P=.003), but no differences in major amputation (8 vs. 11%, P=.25).
CONCLUSIONS - Patients with diabetic foot wounds associated with arterial insufficiency and increased WIfI or UT stage were more likely to have an unplanned 30-day readmission. While aggressive multidisciplinary care of patients with diabetic foot wounds was associated with excellent long-term outcomes, this comes with a significant LOS and rate of readmission. CMS penalization for unplanned readmission should take into account WIfI and/or UT staging.
| Unplanned Readmission (n=62) | Initial or Planned Admission (n=274) | P-value | |
| Wound Etiology | .04 | ||
| Amputation | 8 (12.9%) | 27 (9.9%) | |
| Arterial | 21 (33.9%) | 48 (17.5%) | |
| Traumatic | 1 (1.6%) | 12 (4.4%) | |
| Neuropathic | 28 (45.2%) | 174 (63.5%) | |
| Pressure | 4 (6.5%) | 11 (4.0%) | |
| Venous | 0 | 2 (0.7%) | |
| UT Diabetic Wound Stage | .03 | ||
| A | 0 | 25 (9.1%) | |
| B | 26 (41.9%) | 133 (48.5%) | |
| C | 17 (27.4%) | 55 (20.1%) | |
| D | 19 (30.7%) | 61 (22.3%) | |
| WIfI Composite Score | .04 | ||
| 1-4 | 17 (27.4%) | 123 (44.9%) | |
| 5-9 | 40 (64.5%) | 132 (38.2%) | |
| Stage 5 | 5 (8.1%) | 19 (6.9%) |
Back to 2017 Program
