Fall mechanisms, bone strength, and hip fractures in elderly men and women in Taiwan

Summary: Three modifiable factors of fall direction, poor bone strength, and depression were associated with an increased risk of hip fractures for elderly men and women; fall direction was a much stronger predictor than the other two. When a fall occurs, changing fall direction may be most effective to prevent hip fractures. Introduction: A matched case-control study was conducted to identify risk factors for hip fractures in elderly men and women in Taiwan. Methods: Cases were defined as persons who visited the emergency room due to a fall and were diagnosed with a first hip fracture. For each case, a control was matched by gender and time of falling, selected from persons who sought care at the same emergency room due to a fall resulting in injury other than a hip fracture. In total, 85 paired men and 221 paired women were included. Results: For men, backward, straight-down, and sideways falls were associated with 10.8-, 13.6-, and 15.2-fold increased risks of hip fractures, respectively, compared with forward falls. Poor bone strength and depression were associated with 2.27- and 2.85-fold increased risks of hip fractures, respectively, while dependence in ≥3 activities of daily living was associated with a fivefold lower risk. For women, compared with forward falls, backward, straight-down, and sideways falls were associated with 10.2-, 9.86-, and 12.8-fold increased risks of hip fractures, respectively. Living in a rented house, poor bone strength, depression, and use of antidiabetics were associated with 1.65-, 2.78-, 1.89-, and 1.92-fold increased risks of hip fractures, respectively. Hormone replacement therapy was associated with a fivefold lower risk of hip fractures. Conclusions: While bone strength and depression can be risk factors for hip fractures in elderly people, the direction of the fall was the strongest predictor. Some risk factors differed between elderly men and women.