The primary analysis compared changes from entry to 24 and 48 weeks in lumbar spine BMD between Groups 1A and 1B combined (both on alendronate for initial 48 weeks) vs. Group 2 (on placebo for 48 weeks). Study participants were unblinded after 96 weeks of follow-up (the primary completion date) but remained on study, off study treatment, for an additional 48 weeks.