Preoperative Anaemia Increases the Likelihood of 1-Year Mortality After Hip Fracture.

Abstract

Background: Preoperative anaemia has been shown to increase the risk of adverse outcomes following hip fracture. To date, the association between haemoglobin (Hb) on admission and longer-term outcomes has not been studied extensively in the Irish hip fracture population. This study aimed to ascertain the mean Hb on admission and investigate the relationship with 1-year mortality. Methods: A retrospective review of all hip fracture cases in older adults discharged from an Irish urban trauma centre over a 4-year period was conducted. Hb on admission was obtained using electronic patient records. Mortality status was obtained via the Inpatient Management System and correlated with the Irish Death Events Register. Logistic regression was performed on a range of routinely collected patient and care pathway variables. Results: A total of 833 patients were included. Mean Hb on admission was 12.1 g/dL (SD 1.7), with 11.4% (95/833) of patients having a Hb ≤ 10 g/dL. Within 1 year of fracture 20.5% (171/833) of patients had died. On multivariate analysis, those with a Hb ≤ 10 g/dL on admission were 76% more likely to die within one year (OR 1.76, p < 0.02, 95% CI 1.07-2.90) compared to those with a Hb ≥ 10.1 g/dL. Patients admitted from a nursing home were also more likely to die within 1 year (OR 2.09, p < 0.001, 95% CI 1.26-3.45), compared to those admitted from home. Early postoperative mobilisation (OR 0.32, p < 0.001, 95% CI 0.22-0.48) and female gender (OR 0.49, p < 0.001, 95% CI 0.34-0.71) reduced the likelihood of 1-year mortality (AUC 0.71). Conclusion: Anaemia is common in hip fracture patients and may be viewed as a surrogate marker of frailty. In this cohort, Hb ≤ 10 g/dL on admission was a statistically significant predictor of 1-year mortality. Recognising and managing anaemic patients preoperatively may provide an opportunity to improve longer-term outcomes in hip fracture patients.