William J. Doherty, Thomas A. Stubbs, Andrew Chaplin, Avan A. Sayer, Miles D. Witham, Antony K. Sorial
Introduction
Independent validation of risk scores after hip fracture is uncommon, particularly for evaluation of outcomes other than death. We aimed to assess the Nottingham Hip Fracture Score (NHFS) in predicting a range of important outcomes after hip fracture.
Methods
Consecutive, surgically managed hip fracture patients were identified from the Northumbria hip fracture database between 2014-2018. C-statistics were calculated to test the discriminant ability of the NHFS, Abbreviated Mental Test Score (AMTS), and American Society of Anesthesiologists (ASA) grade for mortality and functional independence at discharge, 30 days and 120 days; length of stay; and postoperative complications.
Results
We analyzed data from 3208 individuals, mean age 82.6 (SD 8.6). 2192 (70.9%) were female. 194 (6.3%) died during the first 30 days, 211 (6.8%) had no mobility at 120 days, 141 (4.6%) experienced a postoperative complication. Median length of stay was 18 days (IQR 8-28). For mortality, C-statistics for NHFS (0.68-0.69) were similar to ASA and AMTS. For postoperative mobility, C-statistics for NHFS (0.74-0.83) were similar to AMTS and better than ASA (0.68-0.71). Length of stay was significantly correlated with each score (P < .001 by Jonckheere-Terpstra test), with NHFS and
AMTS showing inverted U-shaped relationships. For postoperative complications, C-statistics for NHFS (0.54-0.59) were similar to ASA and AMTS.
Conclusions
The NHFS performed consistently well in predicting functional outcomes, moderately in predicting mortality, but less well in predicting length of stay and complications. There remains room for improvement by adding further predictors such as measures of physical performance in future analyses.