Table 1.

Efficacy of bisphosphonates from extension trials

Study	Drug	Extension time	Mean difference in BMD in bisphosphonate vs placebo	Fracture risk reduction in continuous bisphosphonate group
FLEX trial [24]	Alendronate	5 years	Total hip: 2.4% Femoral neck: 1.9% Lumbar spine: 3.7%	Clinical vertebral: RR 0.45 (CI 0.24–0.85) Morphometric vertebral: RR 0.86 (CI 0.60–1.22)
HORIZON-PFT [25]	Zoledronic acid	3 years	Femoral neck: 1.04% Total hip: 1.22% Lumbar spine: 2.03%	Morphometric vertebral: OR 0.51 (CI 0.26–0.95) Clinical vertebral: HR 1.81 (CI 0.53–6.2) Nonvertebral: HR 0.99 (CI 0.7–1.5)