Effectiveness of bisphosphonates on nonvertebral and hip fractures in the first year of therapy: the risedronate and alendronate (REAL) cohort study.
BACKGROUND
Randomized clinical trials have shown that risedronate and alendronate reduce fractures among women with osteoporosis. The aim of this observational study was to observe, in clinical practice, the incidence of hip and nonvertebral fractures among women in the year following initiation of once-a-week dosing of either risedronate or alendronate.


METHODS
Using records of health service utilization from July 2002 through September 2004, we created two cohorts: women (ages 65 and over) receiving risedronate (n = 12,215) or alendronate (n = 21,615). Cox proportional hazard modeling was used to compare the annual incidence of nonvertebral fractures and of hip fractures between cohorts, adjusting for potential differences in risk factors for fractures.


RESULTS
There were 507 nonvertebral fractures and 109 hip fractures. Through one year of therapy, the incidence of nonvertebral fractures in the risedronate cohort (2.0%) was 18% lower (95% CI 2% - 32%) than in the alendronate cohort (2.3%). The incidence of hip fractures in the risedronate cohort (0.4%) was 43% lower (95% CI 13% - 63%) than in the alendronate cohort (0.6%). These results were consistent across a number of sensitivity analyses.


CONCLUSIONS
Patients receiving risedronate have lower rates of hip and nonvertebral fractures during their first year of therapy than patients receiving alendronate.
Silverman
S L
SL
Cedars-Sinai Medical Center and David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90211, USA. stuarts@omcresearch.org
Watts
N B
NB
Delmas
P D
PD
Lange
J L
JL
Lindsay
R
R
D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004341:Drug Evaluation; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D006620:Hip Fractures / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D012189:Retrospective Studies; D000068296:Risedronic Acid; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
D050071:Bone Density Conservation Agents; D000068296:Risedronic Acid; D012968:Etidronic Acid; D019386:Alendronate