Mortality and morbidity following hip fractures related to hospital thromboprophylaxis policy.

Chemical thromboprophylaxis has been shown to reduce the incidence of venous thromboembolism (VTE) for patients with fractures of the hip, but it is not known with certainty whether it use also reduces mortality. Using postal and telephone questionnaires we collected data from English National Health Service (NHS) hospitals about their thromboprophylaxis policy for hip fractures patients from April 2003 to April 2007. Using Hospital Episode Statistics (HES) we ascertained in-hospital mortality rates at 30 days and at one year following admission to hospital. Unplanned hospital readmission rates for all causes (including episodes of thromboembolism and bleeding) within 30 days (all years) and one year (2003 to 2005) were also established. A total of 150 hospitals were contacted and data gathered from 62 hospitals (response rate 41.3%) There were 255841 patients with neck of femur fractures during this five year period who were assessed for morbidity and mortality, and we correlat these with thromboprophylaxis policy. There was no significant difference in hospital readmission within 30 days, or diagnosis of thromboembolism or haemorrhage among hospitals with different thromboprophylaxis policies. The hospitals using low molecular weight heparin (LMWH) in half the dose recommended by the British National Formulary had significantly reduced mortality in-hospital (odds ratio (OR) 0.79, 95% CI 0.69-0.90, P=0.0006), at 30 days (OR 0.8 (0.70 - 0.92), P=0.001) and at one year (OR 0.89 (0.80 - 1.00), P=0.050), compared with those with no such policy. Our data suggest that the thromboprophylaxis regimen for patients with fracture neck of femur should be half dose LMWH for the duration of the hospital stay.