Optimizing discharge planning: predictors of prolonged hospital length of stay after isolated femoral shaft fracture fixation.

purposeLength of hospital stay (LOS) is a critical metric in orthopedic care. While factors influencing LOS in hip fractures are known, research on isolated femoral shaft fractures is limited. This study’s main purpose was to identify the demographic, clinical, and treatment-related factors that prolong LOS specifically in this patient population.

methodsA retrospective cohort study was conducted on 551 patients treated for isolated diaphyseal femur fractures (OTA/AO 32 A–C). Multiple imputation (25 iterations) was utilized to address missingness in 16.3% of the sample, resulting in a final analytical cohort of 503 patients. Due to the right-skewness and overdispersion of LOS, a multivariate negative binomial regression model with a log link was employed to determine the association between LOS and independent variables, including Body Mass Index (BMI), discharge hemoglobin (Hgb), red blood cell transfusion (RBCT) status, age, sex, and comorbidities. Hospitalizations exceeding 9 days were identified as extreme outliers using Tukey’s hinges. These outliers were excluded to limit the analysis to typical postoperative hospitalizations. Interaction terms were included to evaluate the relationship between discharge Hgb and age. Model coefficients were exponentiated and interpreted as incidence rate ratios representing proportional changes in expected LOS.

resultsThe mean LOS was 3.22 days (SD = 2.19). Median LOS was 3 days (IQR = 3).Multivariate analysis demonstrated that each 1-unit increase in BMI was associated with a 1% increase in expected LOS (P = 0.003). A significant interaction was identified between discharge Hgb and age; for patients under 60 years old, each 1 g/dL increase in discharge Hgb was associated with a 3–5% reduction in LOS (P < 0.05). Notably, RBCT status, sex, and pre-existing comorbidities were not significant independent predictors of LOS. Postoperative deep vein thrombosis (DVT) incidence was remarkably low (0.6%).

conclusionLOS for isolated femur fractures is dictated by BMI and postoperative hematologic status rather than pre-existing comorbidities. The impact of discharge Hgb is age-specific, exerting a significant protective effect primarily in patients under 60 years old. In contrast, BMI consistently prolongs LOS regardless of age, likely due to delayed mobilization. These findings suggest that focusing on early mobilization and hematologic optimization can improve hospital efficiency in the trauma setting.