Fig. 1

Model structure for screening strategies to identify prevalent VF. T, test; VF, vertebral fracture; VFA, vertebral fracture assessment; (+), positive; (−), negative. a Simplified decision tree: Subjects who tested positive for prevalent VF were treated with anti-osteoporotic drugs, and the cycle length of the screening test was two years. b State transition diagram: the Markov model had five health states: No VF, Prevalent VF, Post VF, New VF, and VFA impossible. If the diagnosis of the new VF has been made once, patients with drug therapy are ruled out of the simulation targets