30-Day Mortality Rates in Fractured Neck of Femur: Nottingham Hip Fracture Score vs Surgical Outcome Risk Tool

Abstract

Objectives: The Nottingham hip fracture score (NHFS) and the Surgical outcome risk tool (SORT) are both validated scoring systems used to predict mortality rates in patient with Fractured neck of femur (FnF). The primary aim of this study was to compare the accuracy of the predicted 30-day mortality rates between NHFS and SORT in patients with FnF. The secondary aim was to investigate the influence of patient and surgical factors on 30-day mortality. Methods: The NHFS and SORT score was collected from 212 patients admitted with FnF. Variables including hip fracture type, surgical procedure and peri-operative haemoglobin, gender and ASA grade were also collected and further analysed to assess their influence on 30-day mortality rates. Results: Overall actual 30-day mortality rate for the study population was 11.3% (n=24). There was a significant difference between the mean predicted 30-day mortality for the NHFS (8.0%) and the SORT score (7.0%, p=0.006). The was no difference in mortality rates between the different fracture types (p=0.889). There was a significant difference in mortality rates when comparing surgical procedures (p=0.031). Patients who had a notable fall in haemoglobin peri-operatively had significantly higher mortality rates (p<0.001). Males had significantly higher mortality rates compared to females (20.0% vs 8.6% respectively, p=0.027). Higher ASA grades also had significantly higher mortality rates (p=0.003). Conclusion: NHFS was found to be significantly more accurate at calculating 30-day mortality rates compared to the SORT score in patients with FnF. Surgical procedure and patient factors including gender, ASA grade and peri-operative haemoglobin also significantly influenced mortality rates but fracture type did not.