C-reactive protein is an independent predictor for 1-year mortality in elderly patients undergoing hip fracture surgery

Numerous factors are associated with mortality after hip fracture surgery in elderly patients. The aim of this study was to investigate whether preoperative C-reactive protein (CRP) was an independent risk factor for 1-year mortality after hip fracture surgery in the elderly. The electronic medical records of 772 elderly patients (age ≥ 65 years) undergoing hip fracture surgery from May 2003 to November 2011 were reviewed retrospectively. The patients comprised a high CRP group (>10.0 mg/dL) and low CRP group (≤10.0 mg/dL), based upon preoperative CRP levels. The overall 1-year mortality was 14.1%; the value was significantly higher in the high CRP group than in the low CRP group (31.8% vs 12.5%; P < 0.001). On binary logistic regression, body mass index (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.88-0.99; P = 0.025), history of malignancy (OR, 2.59; 95% CI, 1.47-4.57; P = 0.001), American Society of Anesthesiologists physical status (ASA PS) class 3-4 (OR, 1.96; 95% CI, 1.25-3.07; P = 0.003), preoperative albumin (OR, 0.39; 95% CI, 0.25-0.61; P < 0.001), preoperative CRP > 10.0 mg/dL (OR, 2.04; 95% CI, 1.09-3.80; P = 0.025), postoperative intensive care unit (ICU) admission (OR, 2.29; 95% CI, 1.15-4.59; P = 0.019), and creatinine on the second postoperative day (OR, 1.20; 95% CI, 1.00-1.45; P = 0.048) were independent predictors of 1-year mortality after hip surgery. Male gender and low preoperative hemoglobin were associated with in-hospital mortality, whereas delayed surgery and femoral neck fracture were related to the 6-month mortality. Low preoperative albumin and low body mass index predicted the 6-month and 1-year mortality. An increased preoperative CRP level, particularly >10.0 mg/dL, was associated with the 1-year mortality after hip fracture surgery in the elderly. In addition, a history of malignancy, high ASA PS score, and postoperative ICU admission were related to mortality after hip fracture.