Osteoporosis Risk Tool Predicts Fracture Risk Within 12 Months

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Osteoporosis Risk Tool Predicts Fracture Risk Within 12 Months

Laurie Barclay, MD

May 24, 2004 ‹ A new classification tool for osteoporosis accurately

predicts fracture risk within 12 months, according to the results of a study

published in the May 24 issue of the Archives of Internal Medicine. The

investigators suggest that this can be used in clinical practice.

" Effective strategies to reduce patients' risk of fracture must include

identification and management of individuals who are osteopenic and at high

risk of near-term and lifetime fractures, " write D. , MD, from

the Colorado Center for Bone Research in Lakewood, and colleagues.

Although bone mineral density (BMD) is the most important predictor of bone

fracture in postmenopausal women without previous fracture, osteopenic women

with even moderately low T scores are also at risk for bone fracture.

However, there is little agreement on the optimal T score at which to begin

dietary and pharmacologic treatment to reduce fracture risk.

Many clinicians use the World Health Organization (WHO) definition of

osteoporosis (T score of -2.5 or lower) as the threshold for treatment, but

the National Osteoporosis Foundation suggests that women with a T score of

-2.0 or less or -1.5 or less with at least one risk factor should be treated

to reduce fracture risk.

The investigators in this study analyzed data from 57,421 postmenopausal

white women with baseline T scores of -2.5 to -1.0 who were followed for one

year after BMD testing. Using 32 risk factors for fracture, they constructed

an algorithm to predict future risk of fracture.

During follow-up, 1,130 women had new fractures. The best predictors of

fracture were previous fracture, a T score at a peripheral site such as heel

or forearm of -1.8 or less, self-rated poor health status, and poor

mobility. Based on the new algorithm, 55% of the women were identified as

being at increased risk for fracture.

Regardless of T score, women with a previous fracture had a risk of 4.1%.

Women with T scores of -1.8 or less or with poor health status had a risk of

2.2%, and women with poor mobility had a risk of 1.9%. The algorithm

correctly classified 74% of women who experienced a fracture within one

year.

Study limitations include possible differences in fracture risk in women who

responded to the follow-up survey and in the 18% of nonresponders;

collection of fracture information by self-report; inability to address the

value of risk factors or peripheral BMD to predict nonclinical spine

fractures; lack of data on some risk factors for fracture, such as muscle

strength and propensity to fall; and derivation of the algorithm from

one-year fracture data, so that its utility for long-term fracture

prediction is unknown.

" This classification tool accurately identified postmenopausal women with

peripheral T scores of -2.5 to -1.0 who are at increased risk of fracture

within 12 months, " the authors write. " It can be used in clinical practice

to guide assessment and treatment decisions. "

Merck and the International Society for Clinical Densitometry funded and

managed this project. Several authors receive consulting fees from Merck.

In an accompanying editorial, Mazanec, MD, from the Cleveland Clinic

Foundation in Ohio, notes that " in 2004, osteoporosis clearly qualifies for

screening as a societal health problem of enormous and increasing

magnitude. "

According to WHO criteria, the prevalence of osteoporosis in U.S. women

older than 50 years is 13% to 18%, and nearly half have osteopenia. BMD,

which is responsible for 70% of bone strength, is the most important

predictor of fracture risk. Dr. Mazanec notes that this study and an

accompanying article by Siris and colleagues rely heavily on BMD

measurements to help determine fracture risk in older women.

" Taken together, these studies underline the importance of ongoing

refinement of screening strategies in asymptomatic women and the need to

evaluate therapeutic efficacy, i.e., fracture risk reduction in high-risk

osteopenic patients, " he writes. " Clearly, the expanding array of effective

therapeutic agents for osteoporosis reinforces the need for appropriate

screening strategies to identify therapeutic candidates. "

Arch Intern Med. 2004;161:1113-1120, 1047-1048

Reviewed by D. Vogin, MD