Prediction of 30-day mortality after hip fracture surgery by the Nottingham Hip Fracture Score and the Surgical Outcome Risk Tool

Abstract

SummaryThe care of the elderly with hip fractures and their outcomes might be improved with resources targeted by the accurate calculation of risks of mortality and morbidity. We used a multicentre national dataset to evaluate and recalibrate the Nottingham Hip Fracture Score and Surgical Outcome Risk Tool. We split 9,017 hip fracture cases from the Anaesthesia Sprint Audit of Practice into derivation and validation data sets and used logistic regression to derive new model co-efficients for death at 30 postoperative days. The area (95% CI) under the receiver operator characteristic curve of 0.71 (0.67-0.75) indicated acceptable discrimination by the Nottingham Hip Fracture Score and acceptable calibration fit (Hosmer-Lemeshow test), p = 0.23, with a similar discrimination by the Surgical Outcome Risk Tool, 0.70 (0.66-0.74), which was miscalibrated to the observed data, p = 0.001. We recommend that studies test these scores for patients with hip fractures in other countries. We also recommend these models are compared with case-mix adjustment tools used in the UK.

Accuracy of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity score and the Nottingham risk score in hip fracture patients in Sweden — A prospective observational study

“…Our result of an area under the ROC curve of 0.67 is within the range of 0.64‐0.77 reported in previous studies12, 19, 21, 23, 32 and suggests an equally poor discrimination for POSSUM and the NHFS in our cohort. Interestingly, while some studies have demonstrated superior discrimination by scores specifically designed for hip fracture patients12 compared to that of general surgical risk scores several other studies have not been able to demonstrate such a difference 19, 32.…”

“…It is somewhat simpler than the POSSUM and P‐POSSUM scores and does not require insertion of operative data, and is thus more suited to preoperative risk evaluation. External validation has to our knowledge only been performed in United Kingdom and in the Netherlands 12, 21, 22, 23. A recent comparison between the POSSUM and the NHFS suggested that discrimination by the NHFS was superior to that of the POSSUM score 12.…”

Secondary analysis of outcomes after 11,085 hip fracture operations from the prospective UK Anaesthesia Sprint Audit of Practice (ASAP-2)

“…We calculated the Nottingham Hip Fracture Score for all patients , with which we adjusted outcomes for patient age, cognitive function, residential status and comorbidities. We determined patient survival at 30 postoperative days from the NHFC, cross‐referenced with data from Egton Medical Information Systems Ltd (Leeds, UK).…”

Tight intra-operative blood pressure control versus standard care for patients undergoing hip fracture repair – Hip Fracture Intervention Study for Prevention of Hypotension (HIP-HOP) trial: study protocol for a randomised controlled trial

“…Usual place of residenceDate/time of admissionMobility prior to fractureMedical co-morbiditiesFrailty score [21]: 35-point version of Searle frailty index (excluding variables likely to be undefinable in patients with hip fracture)NHFS [15, 22–24]Full blood countUrea and electrolytesArterial blood pressure (systolic, mean and diastolic)Last ward measurementMean of two measurements 5 minutes apart in anaesthesia room before induction of anaesthesia …”