Elderly Osteoporotic Women 3 Times More Likely to Fracture Hip

Lisa Langsetmo, PhD

When diagnosed with osteoporosis, women aged 80 years or older face a three-fold probability of a hip fracture within 5 years, according to a new analysis for the Study of Osteoporotic Fractures (SOF) Research Group.

The severity is sharpened even further for women diagnosed with comorbidities or poor prognosis.

The investigators, led by Lisa Langsetmo, PhD, of the University of Minnesota Twin Cities, conducted a prospective cohort study from March 2018 - January 2019 across 4 US sites, including 1528 women (mean age 84.1 years) identified as potentially able to benefit from osteoporosis treatment.

The 1528 women are from a larger original sample pool of 9704 women aged 65 years or older from 1986 - 1988. At that time, the observed women were able to walk unassisted. From 2002-2004, all active, surviving women were encouraged to participate in a 16-year follow-up visit, leading 4261 women (88% of surviving participants) to return questionnaire data, and 2692 of these to complete an in-clinical examination, including measurement of hip bone mineral density (BMD).

The final analytical cohort contained 1528 women who had never been previously treated for osteoporosis.

Not all of these women in the cohort were diagnosed with osteoporosis—they were divided into 2 groups based on the National Bone Health Alliance’s disease definition criteria for having clinical osteoporosis (n= 761) or being without osteoporosis but at high fracture risk (n= 767).

Use of drug treatment to prevent fractures decreases as age increases. Concerns about comorbidities and prognosis, however, also increase with age.

Randomized clinical trials among women and men aged 50 years and older have shown that those with clinically recognized osteoporosis benefit significantly from drug treatment that prevents fractures. Unfortunately, the majority of those trials exclude or underrepresent women aged 80 or older and/or women with multiple comorbidities or poorer prognosis.

As a result, further research is necessary to determine the proper course of action for older women with osteoporosis, who face not only the risk of a related fracture, but age-related mortality risks.

The 1528 women in the final stage of the new study were contacted every 4 months regarding their overall health and any hip fractures. The five-year hip fracture probability also accounted for competing mortality risk and comorbid conditions assessed by self-report, as well as prognosis estimated using a mortality prediction index. Components considered when determining mortality risk included age, sex, specific comorbid conditions, body mass index, and difficulty performing basic and instrumental activities of daily living, all of which affected mortality rate on an index range of 0 - 21.

During the following 5 years, 125 (8%) of the women experienced a hip fracture. Just 287 (18.8%) died without ever experiencing a hip fracture.

The 5-year mortality probability was 24.9% (95% CI: 21.8 - 28.1) among women with osteoporosis as compared to 19.4% (95% CI: 16.6 - 22.3) among women who were only at high fracture risk. Both groups saw an increase in mortality alongside comorbidities and poorer prognosis.

Fracture probability across 5 years, on the other hand, was 13% (95% CI: 10.7 - 15.5) among women with osteoporosis and 4% (95% CI: 2.8 - 5.6) among the other group. Comorbidities or worse prognosis further broadened the difference. Among women with 3 or more comorbid conditions, hip fracture probability was 18.1% (95% CI: 12.3 - 24.9) among women with osteoporosis, while it was 2.5% (95% CI: 1.3 - 4.2) among the other group.

In summary, women with osteoporosis who are at least 80 years old have a high five-year probability of hip fracture, even when comorbidities, poor prognosis, and competing mortality risk are taken into account. Women who have a high fracture risk but nevertheless do not have osteoporosis face a contrarian burden: their risk of hip fracture is vastly outweighed by their mortality risk, which is worsened by comorbidities or negative prognosis.

An accompanying commentary, written by a trio of investigators from Harvard Medical School, explored how this information ought to affect the decision to treat osteoporosis with drugs (or not) in older female patients.

If a patient is likely to die prior to ever suffering a fracture, then osteoporosis treatment shouldn’t take priority. On the other hand, if women 80 or older do, as the new study shows, face higher risk of fracture than of death from other causes, then proceeding with drug treatment is a logical decision.

This is especially relevant in light of a survey of older women, cited by the commentary, in which 80% reported a preference for death rather than a hip fracture leading to institutionalization.

The study, “Association of Disease Definition, Comorbidity Burden, and Prognosis With Hip Fracture Probability Among Late-Life Women,” was published online in JAMA.