The majority of clinical fractures including hip fractures occur among adults aged 80 years and older, but there is a paucity of evidence to guide assessment of fracture risk versus competing mortality risk in this expanding patient population. Clinicians have difficulty identifying late life patients who are at highest risk of fracture since expected survival strongly impacts this risk. No currently available fracture risk assessment tool adequately addresses important issues relevant to fracture prediction in the oldest old, including selection of appropriate timeframes for fracture prediction, inclusion of key risk factors for late life fractures and mortality, and consideration of a patient's competing mortality risk given his/her set of risk factors. Our preliminary data suggests that addition of non-skeletal risk factors such as the frailty phenotype to a fracture prediction model will improve its performance in late life adults. Thus, there is a critical need for pragmatic fracture risk assessment models that better identify women and men in the 9th and 10th decades of life at high risk of fracture. Our study will combine comprehensive data collected in three large epidemiologic cohorts (Study of Osteoporotic Fractures [SOF]; Osteoporotic Fractures in Men Study [MrOS]; Health Aging and Body Composition Study [Health ABC]) to yield fracture prediction models in community-dwelling women and in men aged 80 years and older that clearly define relationships between individual and combined risk factors for fracture accounting for the competing risk of mortality and demonstrate superior performance to that of existing tools. We will generate estimates of 5-year and lifetime risks considering relevant late life non-skeletal predictors of both fracture and mortality including multimorbidity, functional limitations, polypharmacy, the frailty phenotype and its components such as shrinking, weakness and slowness. In addition, we will evaluate the role of BMD in fracture prediction including its interaction with late life non-skeletal risk factors. Valid lifetime risk assessment with adequate consideration of a patient's competing mortality risk is warranted to identify those at highest risk of fracture prior to death. In addition, a 5-year prediction time frame among these high risk patients accounting for competing mortality risk is needed for clinical decision making given the anticipated time horizon of benefit of interventions to lower fracture risk and reduced life expectancy. Successful achievement of our aims will improve clinical decision making by clearly identifying higher risk patient subgroups who should be targeted for fracture screening and prevention approaches as fracture risk is high despite consideration of competing mortality risk and lower risk subgroups where these strategies may have minimal benefit as competing risk of death far outweighs fracture risk. These results are essential to guide fracture risk assessment and shared cli...