The 2-year, randomized, double-blind, active-controlled fracture endpoint VERO study included postmenopausal women with established osteoporosis, who had at least 2 moderate or 1 severe baseline vertebral fractures (VFx), and BMD T-score ≤-1.5. Patients were treated with either s.c. daily teriparatide 20 μg or oral weekly risedronate 35 mg. As previously reported, the risk of new VFx and clinical fractures (a composite of clinical VFx and non vertebral fragility fractures [NVFFx]) was statistically significantly reduced with teriparatide compared with risedronate. Here we present the prospectively planned subgroup analyses of fracture data across subgroups which were predefined by the following baseline characteristics: age, number and severity of prevalent VFx, prevalent non vertebral fractures (NVFx), glucocorticoid use, prior osteoporosis drugs, recent bisphosphonate use, clinical VFx in the year before study entry, and baseline BMD. Heterogeneity of the treatment effect on the primary endpoint (new VFx), and the 4 key secondary endpoints (including clinical fractures and NVFFx) were investigated by logistic and Cox proportional hazards regression models. 1,360 women were randomized and treated (680 per group). Mean age was 72.1 years, mean (SD) number of prevalent VFx was 2.7 (2.1), 55.4% had a BMD T score <-2.5, 36.5% had a recent clinical VFx, 28.3% had a prior major NVFx, 43.2% were osteoporosis drug naïve, 39.3% were recent bisphosphonate users, and 9.3% were taking glucocorticoids at a prednisone-equivalent dose of >5 mg/day. For most fracture endpoints, the risk reduction of teriparatide versus risedronate did not significantly differ in any of the subgroups analyzed (treatment-by-subgroup interaction p>0.1), with most subgroups mirroring results from the total study population. In conclusion, in postmenopausal women with severe osteoporosis, the anti-fracture efficacy of teriparatide compared with risedronate was consistent in a wide range of patient settings including treatment-naïve and previously treated patients. This article is protected by copyright. All rights reserved.