TPs were measured from 54 nonselected consecutive patients who visited the vascular surgical outpatient clinic or underwent an endovascular procedure owing to chronic lower limb ischemia. A total of 107 toes were measured. The symptoms were claudication in 51.4 % (n = 55), rest pain in 4.7 % (n = 5), and ulcer or gangrene in 14.0 % (n = 15) of the legs. Of the measured legs, 29.9 % (n = 32) were asymptomatic. Forty patients had undergone endovascular revascularization immediately before the TP measurement. The limits of agreement show the estimated range within which the differences between measurements by the two devices would fall in approximately 95 % of the measurements. The approximate 95 % limits of agreement were calculated as the mean difference ¡À 2 standard deviation and presented in the Bland-Altman scatter plots.
For PPG1 versus LD, the mean difference between two measurements was 14 mm Hg and the limits of agreement were 38 mm Hg. In 47 % of the toes, the difference was ¡Ý10?mm Hg, and in 37 % of the toes, it was ¡Ý15 mm Hg. For PPG2 versus LD, the mean difference between the TPs was 12 mm Hg and the limits of agreement were 24 mm Hg. In 44 % of the cases, the difference was ¡Ý10 mm Hg, and in 30 % , it was ¡Ý15 mm Hg. For PPG1 versus PPG2, the mean difference between two measurements was 14 mm Hg and the limits of agreement were 24 mm Hg. In 50 % of the cases, the difference between the two machines was ¡Ý10?mm Hg, and in 33 % , it was ¡Ý15 mm Hg. Repeatability measured with LD, PPG1, and PPG2 showed that the difference between the first and second measurement was <10 mm Hg in 93 % , 86 % , and 78 % of the cases, respectively, and <15 mm Hg in 98 % , 94 % , and 88 % of the cases, respectively.
TP values vary greatly depending on the device used. However, the repeatability seemed to be acceptable with LD and PPG1. We recommend using same device when circulation is repeatedly assessed in the same patient. Also, we emphasize the importance of clinical examination and low threshold for angiography and revascularization especially in diabetics with wound healing problems.