34 Acta Orthopaedica 2012; 83 (1): 31–35 Table 3. Unadjusted and adjusted risk factors influencing mortality after hip fracture Risk factors Sex (male) Age > 80 years Creatinine (> 90 and >105 μmol/L in women and men, respectively) Potassium (> 4.5 mmol/L) Hemoglobin(< 7 mmol/L) Albumin (< 34 g/L) Platelet count (> 390 × 109/L) CRP (> 50 mg/L) Died (%) Survivors (%) 29 85 52 22 40 8 9 59 24 64 21 4 25 3 5 56 Unadjusted OR (95% CI) 1.26 (0.85–1.85) 3.21 (2.03–5.09) 4.19 (2.91–6.03) 6.10 (3.59–10.4) 1.92 (1.34–2.77) 3.04 (1.48–6.27) 1.78 (0.95–3.32) 1.16 (0.82–1.65) p-value 0.3 < 0.001 < 0.001 < 0.001 < 0.001 0.002 0.07 0.4 Adjusted OR (95% CI) 1.33 (0.86–2.06) 2.92 (1.78–4.81) 2.84 (1.90–4.25) 3.64 (2.01–6.61) 1.13 (0.75–1.71) 3.08 (1.33–7.15) 1.43 (0.69–2.94) 1.11 (0.75–1.62) p-value 0.2 < 0.001 < 0.001 < 0.001 0.6 0.009 0.3 0.6 atinine may be due to congestive heart disease that is severe or poorly regulated. The added strain of hospitalization and sur- gery may lead to the increased mortality. Concerning serum albumin, several previous studies have found it to be associ- ated with mortality after hip fractures (Koval et al. 1999, Pioli et al. 2006, O’Daly et al. 2010, Pimlott et al. 2011, Oztürk et al. 2010). A recent retrospective study of 200 patients (O’Daly et al. 2010) suggested that serum albumin at admission and total lymphocyte count could serve as markers of malnutrition and could be used to predict clinical outcome after hip fractures. However, only levels of albumin at admission and age were found to be independent prognostic factors for 1-year mor- tality by Cox regression analysis, with hazard ratios of 0.93 (95% CI: 0.89–0.98; p = 0.007) and 1.04 (95% CI: 1.007– 1.07; p = 0.02) respectively. In the same study, patients with low albumin at admission had an odds ratio of 4.0 (95% CI: 1.3–12.2; p = 0.02) for dying within 3 months of the frac- ture (as compared to patients with normal albumin levels). In a similar study (Koval et al. 1999), patients were regarded as being malnourished based on total lymphocyte count and albumin levels at admission. Patients with reduced values for both parameters on admission were 3.5 times more likely to die within 1 year of surgery (p < 0.01). A recent study from Canada of 583 hip fracture patients found an association between low serum albumin levels at admission and in-hospital mortality (Pimlott et al. 2010). After multivariate adjustment, an association between low serum albumin and mortality was found to be statistically signifi- cant with an adjusted OR of 2.4 (95% CI: 1.2–5.1; p < 0.05). Almost half of the hip fracture patients had low serum albu- min at the time of admission and it was independently associ- ated with 2.5-fold greater odds of short-term mortality. The association between mortality after hip fracture and reduced hemoglobin levels at admission has also been reported in previous studies (Gruson et al. 2002, Halm et al. 2004, Bhaskar and Parker 2011). In a American study of 548 hip fracture patients (Halm et al. 2004), 60-day mortality after hip fracture was associated with admission levels of hemoglo- bin, giving an adjusted odds ratio of 0.69 (95% CI: 0.49–0.95; p < 0.05). The authors theorized that the degree of anemia is a marker of underlying comorbid illness burden and physiologi- cal reserve. A study on 395 patients found that patients with anemia on admission were more likely to die within 6 or 12 months of hip fracture surgery (Gruson et al. 2002). The sever- ity of anemia was associated with an increased risk of mortal- ity. In the same study, anemia on admission was not predictive of 3-month mortality, but was predictive of mortality at 6 and 12 months after hip fracture. The strength of our study is that the mortality data has been validated. However, we have no information on the cause of death. It is uncertain whether preoperative correction of ele- vated serum creatinine levels would be beneficiary, but we are currently planning studies to investigate this. BD, HJ, JL, MM, and OP designed the study. HJ, HW, and TR gathered the data. HJ and OB analyzed the data. MM wrote the initial draft and BD, HJ, JL, SM, HW, OP, and TR revised it. We would like to thank the Toyota foundation and Grosserer L. F. Foghts foundation. No competing interests declared. Bennet S J, Berry O M, Goddard J, Keating J F. Acute renal dysfunction fol- lowing hip fracture. Injury 2010; 41 (4): 335-8. Bergström U, Jonsson H, Gustafson Y, Pettersson U, Stenlund H, Svensson O. The hip fracture incidence curve is shifting to the right. Acta Orthop 2009; 80 (5): 520-4. Bhaskar D, Parker M J. Haematological indices as surrogate markers of fac- tors affecting mortality after hip fracture. Injury 2011; 42 (2): 178-82. Björkelund K B, Hommel A, Thorngren K G, Lundberg D, Larsson S. Factors at admission associated with 4 months outcome in elderly patients with hip fracture. AANA J 2009; 77 (1): 49-58. Felding P, Rustad P, Mårtensson A, Kairisto V, Franzson L, Hyltoft Petersen P, Uldall A. Reference individuals, blood collection, treatment of samples and descriptive data from the questionnaire in the Nordic Reference Interval Project 2000. Scand J Clin Lab Invest 2004; 64 (4): 327-42.