One-third of patients with AFFs had no bisphosphonate exposure
In this national cohort of adults aged older than 50 years, the absolute rates of AFF per 10,000 person-years were as follows: 0.07 in nonusers of bisphosphonates, 1.84 in those with 3-5 years of bisphosphonate use, and 4.63 in those with >7 years of bisphosphonate use. As a comparison, the rate of classic hip fracture was 43.8 per 10,000 person-years.
Compared with no bisphosphonate use, the relative risk for AFF was close to 40 times higher with more than 7 years of use, after adjusting for multiple confounders. The risk for AFF was also significantly higher among patients with RA or hypertension and for those who used proton pump inhibitors.
“Note that age, gender, and previous fracture were not associated with the risk of AFF” after controlling for multiple confounders, Dr. Bauer stressed.
The relative risk for AFF fell significantly after it had been withheld from use for more than 1 year.
Among the 189 patients with confirmed AFF, 64 patients (34%) had never taken a bisphosphonate.
Preliminary analysis showed that, among patients with AFF, those who had not been exposed to bisphosphonates were younger, more likely to be male, and less likely to have had a previous fracture, RA, or to have used corticosteroids, proton pump inhibitors, statins, or hormone-replacement therapy.
The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Dr. Bauer and Dr. Morin disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.