Assessment of the relationship between age and the effect of risedronate
treatment in women with postmenopausal osteoporosis: a pooled analysis of four
studies.
Author(s): Boonen S, Klemes AB, Zhou X, Lindsay R.
Affiliation(s): Bone Research Unit, Department of Experimental Medicine, Leuven University,
Leuven, Belgium. steven.boonen@uz.kuleuven.ac.be
Publication date & source: 2010, J Am Geriatr Soc. , 58(4):658-63
OBJECTIVES: To quantify the effect of age on the incidence of
osteoporosis-related fractures and of risedronate treatment on fracture risk in
different age groups in women with postmenopausal osteoporosis.
DESIGN: Data from four randomized, double-blind, placebo-controlled, Phase III
studies were pooled and analyzed.
PARTICIPANTS: The analysis population (N=3,229) consisted of postmenopausal women
with osteoporosis as determined on the basis of prevalent vertebral fractures,
low bone mineral density (BMD), or both.
INTERVENTION: Patients had received risedronate 5 mg daily or placebo for 1 to 3
years.
MEASUREMENTS: The endpoints of interest were the incidence of
osteoporosis-related fractures, clinical fractures, nonvertebral fractures, and
morphometric vertebral fractures. The effect of age on fracture risk and
treatment benefit was examined using Cox regression models with age and treatment
as explanatory variables. The 3-year fracture risk was estimated for patients in
each treatment group at a given age.
RESULTS: Irrespective of treatment, fracture risks were greater in older patients
(P<.001). On average, for every 1-year increase in age, a patient's risk for
osteoporosis-related fracture increased 3.6% (95% confidence interval=2.3-5.0%).
Irrespective of age, risedronate treatment reduced fracture risk 42%.
Risedronate-treated patients had fracture risks similar to those of
placebo-treated patients 10 to 20 years younger.
CONCLUSION: Patients treated with risedronate have a significantly lower fracture
risk, similar to that of untreated patients 10 to 20 years younger.
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