Selective Estrogen Receptor Modulators Have Higher Reduced Hip Fracture Risk Than Alendronate

A retrospective cohort study compared different osteoporosis preventative-medications and found that selective estrogen receptor modulators (SERM) had better hip and major fracture risk reductions than alendronate, while strontium ranelate (SR) had poorer hip and major fracture risk reduction than alendronate.

Osteoporosis preventive-medications have had significant impact on reducing fractures and disability due to bone loss. Many clinical trials have shown that oral bisphosphonates (OBP), SR, and SERM all work to reduce fracture-risk. However, there are few data reports comparing the effectiveness among the different alternative treatments. In a retrospective cohort study, researchers sought to use real-world data to perform a comparative analysis of these anti-osteoporosis prevention medications and determine if any of them are better than the others.

Data from 2 primary care outpatient records were used, the clinical practice research datalink (CPRD) and the Information System for Research in Primary Care (SIDIAP). Alendronate was compared with other OBP, risendronate and ibandronate, SR, and SERM, raloxifene and bazedoxifene. Outcome measures analyzed were hip fractures, major fractures (spine, wrist, proximal humerus, hip), and all non—hip fractures, except digits and skull.

When comparing patients on alendronate with patients on other OBP within the CPRD database, there was an increased hip and major fracture risk in patients on other OBP and no significant differences in non—hip fractures. However, in the SIDIAP database, there were decreased risk of hip, major, and non–hip fractures in patients on other OBP when compared with patients on alendronate. After combining the two population databases, hip, major, and non–hip fracture risk were similar between the 2 groups.

In a comparison between patients on alendronate and patients on SR, investigators did not observe any statistically significant differences in any fracture risk in the CPRD database. However, patients on SR had significantly higher hip and major fracture risks compared with patients on alendronate in the SIDIAP dataset, with 28% higher hip and 6% higher major fracture risk in patients on SR. Once the 2 cohorts of data were joined together, a 26% and 6% higher hip and major fracture risk, respectively, was seen among patients on SR compared with patients on alendronate.

Finally, when patients taking alendronate were compared with patients taking SERM, no statistically significant fracture risk differences were seen between the 2 groups in the CPRD dataset. However, in the SIDIAP dataset, a 27% lower hip, a 23% lower major fracture, and a 23% lower non-hip fracture risk reduction was observed in patients on SERM compared with patients on alendronate. A meta-analysis found a 25%, 23%, and 23% reduced fracture risk reduction of hip, major fractures, and non—hip, respectively, in favor of patients on SERM. One interesting finding was that patients on SERM did not have the same fracture risk effectiveness in secondary fracture risk reductions as primary prevention.

After a retrospective analysis comparison between the major anti-osteoporosis drug classes, SR was shown to have increased hip and major fracture risk compared with alendronate, while SERM had better hip and major fracture risk reduction than alendronate. Additional comparative trials with randomized controlled trials will uniform the data population and provide more verifiable results.

Reference

Khalid S, Calderon-Larrañaga S, Hawley S, et al. Comparative anti-fracture effectiveness of different oral anti-osteoporosis therapies based on “real-world” data: a meta-analysis of propensity-matched cohort findings from the UK Clinical Practice Research Database and the Catalan SIDIAP Database. J Clin Epidemiol. 2018:10;1417-1431. doi: 10.2147/CLEP.S164112.