After Hip Fracture, Earlier Osteoporosis Drug Initiation Tied to Lower Subsequent Fracture Risk

By Lisa Rapaport

June 15, 2020

(Reuters Health) - Patients hospitalized for a hip fracture are less likely to experience a subsequent fracture-related hospitalization if they start anti-osteoporosis medication sooner, a Taiwanese study suggests.

Researchers examined data on 77,930 patients aged 50 years and older hospitalized for hip fractures, including 9,986 people prescribed anti-osteoporosis medications within one year of the index fracture.

Compared to patients who initiated anti-osteoporosis medications 15 to 84 days after the index fracture, those who started treatment 85 to 252 days later, or after 252 days, were more likely to be hospitalized again for a fracture (hazard ratio 1.29 and 1.93, respectively).

"An established hip fracture is a strong predictor of subsequent fracture and according to previous well-established evidence, anti-osteoporosis medications can significantly reduce the risk of subsequent hip fractures," said lead study author Chen-Yu Wang of National Taiwan University Hospital Yunlin Branch.

"Our study goes a step further to suggest that the appropriate timing of anti-osteoporosis medication initiation is a crucial factor to gain the benefit," Wang said by email.

Among patients who did start medication within one year of the index fracture, 18.3% initiated medication very early, within 14 days of the index fracture; 60.1% started medication early, from 15 to 84 days after the fracture; 17.5% started medication late, from 85 to 252 days; and 4.1% started very late, from 253 to 365 days.

People who started treatment sooner tended to have shorter hospital stays, with an average length of stay of 7 days for those who initiated medication very early, compared with 8.2 days for those who started medication late or very late.

Among patients with low adherence to anti-osteoporosis medications, those who started very late were more likely to have another fracture-related hospitalization than those who started early (HR 1.62).

And among patients with high adherence to medications, patients who started very late were more likely to have another fracture-related hospitalization than those who started early (HR 2.56.)

The most common medication used by patients in the study was alendronate (69%).

One limitation of the study is that researchers lacked data on bone mineral density, fracture severity, and calcium and vitamin D supplementation. The exclusion of people who had a fracture prior to the index fracture or who died within one year of the index fracture may also make the results more difficult to generalize.

Even so, the study authors conclude that earlier initiation of medication and good adherence to medication can both help reduce the risk of subsequent fractures.

"The relative risk of having a hip fracture or other osteoporotic fracture is approximately 2-fold higher for most types of prior fracture, however, the increase in risk is not constant with time and is particularly high immediately after the fracture event, sometimes called the period of imminent risk," said Dr. John A. Kanis, a professor emeritus at the University of Sheffield in the UK who wasn't involved in the study.

"This reinforces a rationale for very early intervention immediately after fractures to avoid recurrent fractures," Dr. Kanis said by email.

SOURCE: Bone, online May 25, 2020.