Vertebral fracture risk reduction with risedronate in post-menopausal women with
osteoporosis: a meta-analysis of individual patient data.
Author(s): Adachi JD, Rizzoli R, Boonen S, Li Z, Meredith MP, Chesnut CH 3rd.
Affiliation(s): McMaster University, Hamilton, Ontario, Canada. jd.adachi@sympatico.ca
Publication date & source: 2005, Aging Clin Exp Res. , 17(2):150-6
BACKGROUND AND AIMS: The effect of risedronate, a potent pyridinyl
bisphosphonate, on vertebral fractures in post-menopausal women was evaluated in
randomized, placebo-controlled clinical trials. These trials included two large
vertebral fracture studies that used time-to-event methods to evaluate the
effects of treatment on fracture risk, thereby allowing both the occurrence and
the timing of fractures to be considered.
METHODS: We used individual patient data (IPD) and time-to-event methods to
perform a meta-analysis of the anti-fracture efficacy of risedronate (2.5 or 5 mg
daily) in osteoporotic women enrolled in five double-blind, placebo-controlled
clinical trials. Women were included in the analysis if, at baseline, they had
either at least one prevalent vertebral fracture or a femoral neck bone mineral
density (BMD) T-score of less than -2.5, were at least 1 year post-menopausal,
and had had vertebral fracture assessments (N = 3331).
RESULTS: Risedronate 5 mg daily reduced the risk of radiographically defined
vertebral fracture by 64% (95% CI, 46 to 76%, p < 0.001) in the first year of
treatment and 45% (95% CI, 31 to 57%, p < 0.001) in 3 years. The numbers of
patients who needed to be treated with risedronate 5 mg to prevent one new
vertebral fracture over 1 and 3 years were 21 and 13, respectively. Comparable
findings were observed in sub-populations defined on the basis of either
prevalent vertebral fracture without regard to femoral neck BMD, or femoral neck
BMD without regard to vertebral fracture status. Risedronate significantly
reduced the incidence of clinical (symptomatic) vertebral fractures in the first
6 months of treatment (p < 0.001).
CONCLUSIONS: This meta-analysis, based upon five trials and using IPD and
time-to-event statistical methods, provides a more precise estimate of the effect
of risedronate in reducing vertebral fracture risk in postmenopausal osteoporotic
women than a meta-analysis using summary statistics from the literature.
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