The ability of this genetic score to predict the risk for osteoporosis (defined as T-score<−2.5) and for fracture was modelled in the PERF study using the middle bin as reference (OR=1). Women in the highest bin had 1.56 (95%CI [1.12–2.18]) increased odds for osteoporosis (Fig. 3B), while women in the lowest bin were protected for both osteoporosis (OR=0.38 (95%CI [0.23–0.63])). A model based on the 16 BMD SNPs associated with fracture risk showed that women in the highest bin had 1.60 (95%CI [1.15–2.24]) increased odds for fracture, while women in the lowest bin had a decreased risk for fracture (OR=0.54 (95%CI [0.36–0.83])) (Fig. 3C). Despite serving as a robust proof of principle of the relation between the BMD-decreasing alleles and the risk of osteoporosis and fracture, prediction ability was modest. The ROC analysis showed a significant but relatively small discrimination ability of the genetic score alone with an area under the curve (AUC) of 0.59 (95%CI [0.56–0.62]) for osteoporosis (Supplementary Fig. 8). Adding this score to a model with age and weight alone (AUC 0.75 (95%CI [0.73–0.77])) did not substantially
