Fig. 4

Decision curve analysis of the physical examination. a Primary analysis. b Subgroup analysis of the level of consciousness, X-axis: threshold probability and the weighting, Y-axis: net-benefit, lower figure a, b focusing the threshold range 0–0.05. Colored bold lines: net-benefit of the physical examination under the prevalence 15, 10, 5%; dotted lines: net-benefit by imaging all the patients regardless of physical examination under the prevalence 15, 10, 5%; black bold line: no imaging regardless of physical examination (net-benefit: zero). If the curve of physical examination is under the dotted line of same prevalence, imaging test should be performed in all patients regardless of physical examination. If the curve of physical examination is over the dotted line of same prevalence, imaging test should be performed based on the physical examination findings