Acta Orthopaedica 2012; 83 (1): 31–35 31 Value of routine blood tests for prediction of mortality risk in hip fracture patients Mathias Mosfeldt1, Ole B Pedersen3, Troels Riis1, Henning O Worm1, Susanne van der Mark1, Henrik L Jørgensen2, Benn R Duus1 and Jes B Lauritzen1 Departments of 1Orthopedic Surgery and 2Clinical Biochemistry, Bispebjerg University Hopital, Copenhagen; 3Tissue Typing Laboratory, Department of Clinical Immunology, Copenhagen University Hospital, Copenhagen, Denmark. Correspondence: mathiasmosfeldt@gmail.com Submitted 11-01-20. Accepted 11-10-24 Background There is a 5- to 8-fold increased risk of mortality during the first 3 months after a hip fracture. Several risk factors are known. We studied the predictive value (for mortality) of rou- tine blood tests taken on admission. Methods 792 hip fracture patients were included prospectively; blood tests were taken on admission. Follow-up data on mortality were obtained from the civil registration system. Patients were divided into 2 groups based on whether they had survived at least 90 days after the hip fracture. To estimate which laboratory tests could be used to predict outcome, we used receiver operation characteristic (ROC) curves. Results 3-month mortality could be predicted with 69% accu- racy from the level of plasma creatinine in standard admission blood tests. The mortality in patients with elevated levels of creati- nine was almost 3-fold that of the patients with normal creatinine. Mortality was also associated with age, low blood hemoglobin, high plasma potassium, and low plasma albumin levels. Interpretation Our findings could be of use in identifying patients who might benefit from increased attention periopera- tively.  With the increasingly large proportion of elderly individuals in our populations, the hip fracture incidence curve is shift- ing to the right and hip fracture patients are becoming a more heterogeneous group (Bergström et al. 2009). Almost all excess mortality occurs within the first 3 months after sur- gery (Petersen et al. 2006). A large meta-analysis has found a 5- to 8-fold increased risk of mortality during this period (Haentjens et al. 2010). Several factors that may be predictive of death have been identified (Petersen et al. 2006). We stud- ied the predictive value (for mortality) of routine blood tests. Patients and methods 792 hip fracture patients aged 60 or older who were admitted to the Department of Orthopedics, Bispebjerg University Hos- pital, Denmark from October 2008 through July 2010 were included prospectively. 67 patients aged less than 60 were excluded. Follow-up data on mortality were obtained from the civil registration system on August 1, 2010. Patients were included in the study within the first 3 days after admission. Because of various logistical problems, not all blood tests were done for some patients in the study (Table 1). The patients were divided into 2 groups based on whether they survived for at least 90 days after the hip fracture. The study was approved by the local ethics committee and by the Danish data protection agency, and it was carried out in line with the Helsinki Declaration. Statistics Continuous variables are presented as mean (SD) or median (range). We used student’s t-test for continuous, normally distributed variables, Mann-Whitney 2-sample statistics for skewed distributions, and Chi-squared test to compare cat- egorical variables. To estimate which laboratory tests could be used to predict outcome, we used receiver operation charac- teristic (ROC) curves and calculated the area under the curve (AUC) for the different tests. Cutoff values for the different laboratory tests were predicted using ROC curves or based on the test performance in a normal cohort. Univariate and multivariate logistic regression analyses were used to examine the relationship between the various risk factors and outcome. Values of p < 0.05 were considered statistically significant. Data were analyzed using STATA software. Open Access - This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the source is credited. DOI 10.3109/17453674.2011.652883