Six RCTs (n=9,023) were included in the review.
Five of the 6 RCTs were double-blinded. All of the studies used intention-to-treat analysis.
For women with either a T-score of -2.0 or less or a vertebral fracture, alendronate was associated with a significant reduction in the risk for hip fracture (RR 0.55, 95% CI: 0.36, 0.84, p=0.007; based on data from 9,023 women). The results were consistent across studies (p=0.898). The RRs were similar after excluding each study in turn.
For women with either a T-score of -2.5 or less or a vertebral fracture, alendronate was associated with a significant reduction in the risk for hip fracture (RR 0.45, 95% CI: 0.28, 0.71, p=0.0008; based on data from 6,804 women). The results were consistent across studies (p=0.981). The RRs were similar after excluding each study in turn.
ARRs ranged from 10 to 65 events per 10,000 PYR for women with either a T-score of -2.0 or less or a vertebral fracture, and from 22 to 76 events per 10,000 PYR for women with either a T-score of -2.5 or less or a vertebral fracture. For both groups of women, there was a trend towards greater ARR with increasing age (p<0.05).