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Table 1 Represents the modelled grayscale data for marks made on both upper and lower limbs, the variability of the marks and the effect of surgical prep on each mark

From: Assessing clarity and erasability of commercially available pens for surgical site marking: a comparative study in human volunteers

Pen Mark Mark arm SD Mark leg SD Prep (+/−SD)
A 0.684 0.065 0.038 0.278 +/−0.082
B 0.595 0.057 0.033 0.417 +/−0.123
C 0.519 0.049 0.029 0.418 +/−0.124
D 0.649 0.062 0.036 0.005 +/−0.001
E 0.675 0.064 0.038 0.213+/−0.063
F 0.683 0.065 0.038 0.277 +/−0.082
G 0.620 0.059 0.034 0.421 +/−0.125
H 0.411 0.039 0.023 0.481 +/−0.142
  1. The data model standardises the value for the initial mark (Mark) and the effect of skin preparation (Prep) so that they are the same for both the upper and lower limbs. In the column headed “Mark” a value of 0 indicates no discernible mark and a value of 1 indicates a completely black mark. In the column headed “Prep (±SD)” a value of 0 represents no effect of surgical preparation, and a value of 1 represents complete removal of the mark by surgical prep. The columns headed “Mark Arm SD” and Mark Leg SD” represent the variability of clarity of the marks made on upper and lower limbs