Risk factors of mortality during the first year after low energy osteoporosis fracture: a retrospective case-control study.

INTRODUCTION Osteoporotic fractures are a major public health problem because of the morbidity and mortality of fracture complications. The objective of this study was to examine predictive factors of mortality during the first year after an osteoporotic fracture. METHODS It is a retrospective case-control study using data of a group of 1081 patients aged over 50 years with severe osteoporotic fractures by the Rennes university hospital emergency department from August 2007 to September 2008. Patients (cases) who died during the year following the fracture were compared with others who had survived (controls) one year after the fracture, matched on age, sex and type of fracture. Pre-fracture comorbidities and complications after the fractures were studied. RESULTS Forty-two cases and 126 controls were analyzed without significant differences in age, sex or type of fracture. On univariate analysis, previous neoplasia, neurodegenerative disease, walking aids, thromboembolic complication, post fracture infection, post fracture heart failure, post fracture acute respiratory failure were associated with more mortality after osteoporotic fracture. After multivariate analysis, only previous neoplasia (OR = 4.63 [1.79 - 11.95]; p = 0.02) and acute respiratory failure after fracture (OR = 28.15 [5.75 - 137.9]; p<0.001) were retained as predictive factors during the year following the fracture. CONCLUSION Patients died more often from their co-morbidities than direct complications of their fractures. Osteoporotic fracture seems to be a marker of poor health status and a factor which may hasten the death.