FIGURE 2. A: Outflow fraction [OF] (%) in 37 control limbs and 41 limbs with prior I-FDVT (P < 0.001), on the left. On the right, the limbs with prior I-FDVT are subdivided into those with (+) and without (–) claudication, and those with severe claudication compelling cessation of walking; differences among the three subgroups were not significant (P = 0.58). Data are expressed as median and interquartile ranges. B: Outflow fraction (%) in limbs with prior I-FDVT plotted against the initial claudication distance (m) (r = 0.43, P = 0.018, Spearman’s two-tailed). Patients with shortness of breath were excluded.