Incidence and risk factors for a second hip fracture in elderly women. The Study of Osteoporotic Fractures.
Women with hip fracture have an increased risk of second hip fracture but other risk factors for a second hip fracture have not been established. We sought to determine the incidence and risk factors for second hip fracture, in a prospective cohort study of community-dwelling postmenopausal women over 65 years: the Study of Osteoporotic Fractures. From a cohort of 9,704 women, 632 women with a documented first hip fracture during the study were followed up until a second hip fracture or the end of follow-up. Clinical risk factors and bone mineral density were assessed at the beginning of the study. Fifty-three second hip fractures were validated by radiographs. Women with hip fracture had a 2.3% per year risk of second hip fracture. Women who walked for exercise at baseline were less likely to sustain a second hip fracture with a relative risk (RR) of 0.5 [0.3-0.9], as were those who had normal depth perception (RR=0.5 [0.3-0.9]). Women who lost weight since age 25 years had an increased risk of second incident hip fracture (RR = 2.7 [1.6-4.6]), as did those who had a low calcaneal bone mineral density (RR=1.5 [1.1-2.0] per standard deviation decrease in bone mineral density). Current use of estrogen replacement therapy at baseline was protective (RR=0.5 [0.3-0.9]) up to 2 years of follow-up. We conclude that community-dwelling women with a first hip fracture have a high risk of second hip fracture, and risk factors for this second fracture are similar to those of first hip fracture.
Prevention Sciences Group, University of California at San Francisco, California, USA. roland.chapurlat@laposte.net
R D
RD
Chapurlat
D C
DC
Bauer
M
M
Nevitt
K
K
Stone
S R
SR
Cummings
D000368:Aged; D005260:Female; D016330:Frail Elderly; D006620:Hip Fractures / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008019:Life Style; D015663:Osteoporosis, Postmenopausal / Q000150:complications*; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D014481:United States / Q000453:epidemiology