Alendronate Use and the Risk of Nonvertebral Fracture During Glucocorticoid Therapy: A Retrospective Cohort Study.

Abstract

Glucocorticoids increase the risk of nonvertebral fracture, but no clinical trial has shown that nonvertebral fractures can be prevented by coadministration of an antiosteoporotic drug. To estimate the effect of alendronate on the risk of nonvertebral fracture in older adults taking oral glucocorticoids. Retrospective cohort study using national Swedish registers. Hospitalized care and ambulatory specialist care. Among adults aged ≥50 years (N = 3,347,959), we identified those who initiated oral glucocorticoid therapy from 2006 through 2011 (≥2.5 mg/d of prednisone or equivalent for ≥91 days). The final analysis included 16,890 alendronate users and 16,890 nonusers, who were matched using time-dependent propensity scores. Nonvertebral fracture. This was not prespecified. Over a median follow-up of 14.5 months, the incidence rate of nonvertebral fracture was 2.0 cases/100 person-years in alendronate users and 2.4 cases in nonusers. This difference corresponded to a 16% lower rate in users (hazard ratio 0.84; 95% confidence interval, 0.75 to 0.94). For hip fractures specifically, the rate was 34% lower in alendronate users relative to nonusers (hazard ratio 0.66; 95% confidence interval, 0.55 to 0.78). The association of alendronate use with a lower risk of nonvertebral fracture was strongest in patients who received high doses of glucocorticoid. Alendronate use was associated with a lower risk of nonvertebral fracture, including hip fracture. Similar, but not statistically significant, associations have been reported in meta-analyses of clinical trials.