Table 1.
Comparison of vein depth and diameter according to visibility and palpability.
Fig 1.
Comparison of (A) vein depth and (B) vein diameter between difficulty groups.
The center line of the box represents the median, whereas either end of the box represents the first quartile (Q1) and the third quartile (Q3). The whiskers extending from the box indicate the range of the data (1.5 times from Q1 and Q3, respectively), and the black diamonds outside the box are outliers. Additionally, the white square indicates the mean. p-values are marked in the figure: *** p < 0.001, * p < 0.05.
Table 2.
Multivariate regression analysis to explain the decrease in visibility and palpability.
Fig 2.
Receiver operating characteristic curves for predicting (A) visibility and (B) palpability.
Lines indicate vein depth (red) and vein diameter (green). The dotted line indicates the reference line.