Prevention of vertebral fractures in osteoporosis: mixed treatment comparison of bisphosphonate therapies.
OBJECTIVE
The objective was to compare the efficacy of bisphosphonates regarding the prevention of vertebral fractures in postmenopausal women with osteoporosis.


METHODS
Seven randomized placebo controlled trials investigating the effects of zoledronic acid (one study), alendronate (three studies), ibandronate (one study), and risedronate (two studies) in terms of fractures with a follow-up of 3 years were identified with a systematic literature search. The endpoint of interest was vertebral fractures. Results of all trials were analyzed simultaneously with a Bayesian mixed treatment comparison (MTC). With MTC the relative treatment effect of one intervention to another can be obtained in the absence of head-to-head evidence. MTC can be considered a valid method when included studies are comparable regarding effect modifying baseline patient and study characteristics.


RESULTS
There is a 98% probability that zoledronic acid shows the greatest reduction in vertebral fractures of all four bisphophonates compared. Zoledronic acid showed an OR of 0.28 (95% Credible Interval 0.22; 0.35) relative to placebo, an OR of 0.57 (0.36; 0.92) relative to ibandronate, an OR of 0.54 (0.39; 0.75) relative to alendronate, and an OR of 0.49 (0.34; 0.69) relative to risedronate. Alendronate, ibandronate, and risedronate showed comparable vertebral fracture reductions. Indirect comparisons using a conservative random effects model supported these findings.


CONCLUSIONS
An indirect comparison of findings from placebo controlled randomized studies indicates that zoledronic acid provides a greater vertebral fracture risk reduction in postmenopausal women with osteoporosis than ibandronate, alendronate, or risedronate.
Jansen
Jeroen P
JP
Mapi Values, Boston, MA 02114, USA. jeroen.jansen@mapivalues.com
Bergman
Gert J D
GJ
Huels
Jasper
J
Olson
Melvin
M
D000368:Aged; D000369:Aged, 80 and over; D004164:Diphosphonates / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D050723:Fractures, Bone / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D013131:Spine / Q000503:physiopathology*
D004164:Diphosphonates