Hip fractures sustained in hospital: comorbidities and outcome

Guidelines on the management of hip fracture in the elderly focus on fractures suffered in the community. Between 4% and 7% of hip fractures occur in hospital. Mortality is higher in those who sustain hip fracture in hospital than those who sustain a fracture in the community. However, it is not known if sustaining a nosocomial fracture is an independent risk factor for a poor outcome.

To compare outcomes of hip fracture sustained in the community and sustained while in hospital for another reason. After adjusting for confounders, we sought to determine if sustaining a fracture in hospital was an independent risk factor for a poor outcome.

Using the National Hip Fracture Database, we identified all patients admitted to Leicester Royal Infirmary with hip fracture between July 2009 and February 2013. We extracted demographic data, details of comorbidity, and 30-day and long-term mortality. Age, gender, American Society of Anaesthesiologists (ASA) grade, time to surgery, and survival were compared between patients with hospital-acquired and those with community-acquired hip fracture.

During the study period, 2987 patients were treated for hip fracture; 2984 were included in the study. Of these, 261 (8.7%) sustained the fracture while in hospital. Those who sustained the fracture in hospital were more commonly men (106/261 (41%)) than those with a community-acquired fracture (738/2723 (27%)) and had a worse ASA grade (III or IV, 215/230 (93%) vs 1647/2573 (64%)). Thirty-day mortality was higher in those with a hospital-acquired fracture (48/261 (18%)) than in those with a community-acquired fracture (212/2723 (7.8%)) (p<0.001). However, after adjustment for confounding variables, the association between hip fracture, in-hospital and 30-day mortality was not significant: OR 1.2 (95% CI 0.8 to 2.0), p=0.40. Longer-term mortality was associated with hip fracture in hospital after adjustment for confounding variables in multivariate proportional hazards regression: HR 1.5 (95% CI 1.2 to 1.8), p<0.001.

Patients who sustain hip fractures in hospital are unsurprisingly sicker than those who sustain hip fractures in the community. Although being in hospital is not an independent risk factor, this easily identifiable group of patients are at particular risk of a poor outcome. We suggest that it might be appropriate to consider modifying the guidelines for treatment of hip fracture for this group in an attempt to improve outcome.