To reduce the risk of bone fractures and the complications arising from them, the United States Preventive Services Task force (USPSTF) recommends that all women age 65 and older be tested and treated for low bone mineral density.
The task force also recommends that postmenopausal women aged 50 to 64, get bone mineral density screenings if their 10-year probability of suffering a hip, vertebral, humerus or wrist fracture is 9.3 percent or greater, based on the Fracture Risk Assessment Tool.
A new UCLA-led study published in The Journal of Clinical Endocrinology & Metabolism, however, finds that the USPSTF strategy predicted only slightly more than one fourth of the women who went on to experience major osteoporotic fractures within 10 years. The study also found that two older osteoporosis risk-assessment tools were not much better.
The Osteoporosis Self-Assessment Tool (OST) is based on a person's weight and age, and the Simple Calculated Osteoporosis Risk Estimation Tool (SCORE), uses race, rheumatoid arthritis, history of non-traumatic fracture, age, prior estrogen therapy and weight.
"If we want to prevent fractures, we need tools that help us accurately predict who will suffer these osteoporotic injuries so that we can target these at-risk people for preventive measures," said Dr. Carolyn Crandall, professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA, and the study's primary investigator. "Our results suggest that our current guidelines for screening in younger post-menopausal women do not accurately identify who will suffer a fracture."
The researchers used data from the Women's Health Initiative, which collected details about fractures during 10 years' time and information about osteoporosis risk factors from 62,492 postmenopausal women in the United States from ages 50 to 64. Of the women studied, 85 percent were white, 9 percent were black, and 4 percent were Hispanic. The average age was 57.9.
The study found that overall the USPSTF strategy captured only 25.8 percent of the women who suffered fractures within 10 years, SCORE captured 38.6 percent and OST caught 39.8 percent.
These were the findings for the percentage of women whose fractures were predicted using each risk-assessment tool for three age groups:
|Ages 50-54||4.7 percent||20.5 percent||37.3 percent|
|Ages 55-59||18.5 percent||22.1 percent||57.6 percent|
|Ages 60-64||22.9 percent||36.7 percent||48.1 percent|
The authors note some weaknesses in the study. For instance, the participants of the Women's Health Initiative may be healthier than similarly-aged women doctors see in their clinical practice, so the findings may not generalize to others.
Still, these findings suggest that the current USPSTF screening strategy does not identify the vast majority of younger post-menopausal women who experienced bone fractures, and the other strategies have significant weaknesses as well.
"Neither the USPSTF nor the other two screening strategies performed better than chance alone in discriminating women who did and did not have subsequent fractures," the researchers write. "These findings highlight the pressing need for further prospective evaluation of alternative strategies with the goal of better targeting resources to at-risk young postmenopausal women. Our findings do not support use of the USPSTF strategy or the other tools we tested to identify younger postmenopausal women who are at higher risk of fracture."
Study co-authors are Joseph Larson and Andrea LaCroix of the Fred Hutchinson Cancer Research Center, Seattle; Nelson Watts, Mercy Health Osteoporosis and Bone Health Services, Cincinnati; Margaret Gourlay, University of North Carolina, Chapel Hill; Meghan Donaldson, Centre for Clinical Epidemiology and Evaluation, University of British Columbia; Jane Cauley, Graduate School of Public Health, University of Pittsburgh; Jean Wactawski-Wende, State University of New York, Buffalo; Margery Gass, Cleveland Clinic Center for Specialized Women's Health; John Robbins, Center for Healthcare Policy and Research, UC Davis Medical Center; and Kristine Ensrud, University of Minnesota Medical School and Minneapolis VA Health Care System.
The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201100046C, HHSN268201100001C, HHSN268201100002C, HHSN268201100003C, HHSN268201100004C, and HHSN271201100004C. Crandall received support from UCLA's Jonsson Comprehensive Cancer Center.