Factors associated with substantial preoperative haemaglobin decline in hip fracture patients: a propensity-matched analysis of 1935 cases

Introduction: Hip fractures are associated with substantial blood loss occurring both pre- and intraoperatively. While intraoperative bleeding has been extensively studied, less is known about preoperative haemaglobin decline and its determinants. This study aims to identify factors associated with substantial preoperative blood loss in hip fracture patients and assess its clinical implications. Materials and methods: We retrospectively analysed 1935 hip fracture patients treated at a single tertiary centre between 2019 and 2024. Haemoglobin (Hb) was measured at Emergency Department admission and before surgery. Preoperative Hb decline (ΔHb), used as a surrogate marker for blood loss, was calculated, and patients were categorised into those with substantial (⩾2 g/dL) versus non-substantial (<2 g/dL) preoperative Hb decline. Multivariate regression identified factors associated with substantial preoperative blood loss. Propensity score matching (1:1) was performed to compare clinical outcomes between groups. Results: Substantial preoperative Hb drop occurred in 49.1% of patients. In multivariate analysis, extracapsular fracture type was strongly associated with preoperative blood loss (OR 1.86; 95% CI, 1.54–2.26; p < 0.001), as was advanced age (OR: 1.65 for age >85 vs <65, p = 0.041) and prolonged time to surgery 24-48h (OR: 1.52, 95% CI: 1.06-2.16, p = 0.022). In the propensity-matched cohort (768 patients in each group), substantial preoperative blood loss was associated with higher transfusion rates (17.8% vs 8.1%, p < 0.001) and longer hospital stays (10.8 vs 8.7 days, p < 0.001). Conclusions: Extracapsular fracture type, advanced age (>85 years), and prolonged time to surgery (>24 hours) were independently associated with substantial preoperative Hb decline in hip fracture patients. Substantial preoperative Hb decline was associated with increased transfusion requirements and prolonged hospitalisation. These findings may help identify high-risk patients in whom targeted preoperative haemostatic strategies and closer Hb monitoring warrant further investigation.