Skin Ulcers are Predictors of 30-Day Hospital Readmission, But are Under-represented in the DRG Coding: A Retrospective Case–Control Study From an Italian Internal Medicine Unit

This study retrospectively analyzes all consecutive patients who underwent during a year hospital readmissions, defined as an admission to a hospital within 30 days of discharge, to an Italian Internal Medicine ward. All these data were compared with those from patients who underwent only 1 hospital admission in the same period. The aim of this study was to identify potential novel risk factors for hospital readmissions. In 2018, a total of 3012 patients were hospitalized. Among these, 14.1% (n = 426; mean age, 79.7 ± 11.9; range, 23-100) were defined as readmissions; data were compared with controls (n = 420; 13.9%; mean age, 75.9 ± 14.7; range, 22-99) who had only 1 hospitalization. Cases showed a significantly higher prevalence than controls regarding cerebrovascular disease (77.2% vs 48.1%), cognitive impairment (51.8% vs 26.9%), congestive heart failure (47.6% vs 20.2%), chronic kidney disease (31.7% vs 13.1%), and chronic obstructive pulmonary disease (23.0% vs 14.5%). Skin ulcers were significantly more prevalent among cases (45.1% vs 17.6%). Diagnosis-related group (DRG) analysis showed a higher proportion of “infectious disease” (24.4% vs 15.0%) among the cases than in controls. Despite skin ulcers were very frequent among cases and controls (45.1% vs 17.6%), they were codified as “skin wound” DRG only in 1.4% and 0.2%, respectively. At the DRGs analysis, sepsis (31.6% vs 19.1%), pneumonia (17.1% vs 7.6%), and kidney failure (9.6% vs 3.8%) represented the main significant cause of death in cases compared to controls. Our study confirms that readmissions to Internal Medicine departments are related to the severity of chronic diseases affecting patients. Skin ulcers are present in about half of patients who will be early readmitted within 30 days, but they are almost never reported in DRGs, so more accurate coding is needed. Key challenges for the future are sepsis prevention measures and investing resources in chronic disease assistance, including skin ulcer chronic management.