Fig 1.
Overview of recruited participants.
Patients whose PSA values were below technical detection limit were also correctly identified below the detection limit of 0.014 ng/ml (Roche Cobas e801) in 100% of cases (n = 14).
Fig 2.
The boxplot displays the distribution of venous total-PSA values (ng/mL) measured in the study population(n = 224).
The box represents the interquartile range (IQR; 25th–75th percentile), with the horizontal line indicating the median. Individual measurements are overlaid as gray dots. For improved visualization, extreme values above 15 ng/ml (n = 4) were analyzed separately and are not included in this plot.
Fig 3.
Bland-Altman plot illustrating the differences (capillary – venous) between paired measurements of tPSA against their average values.
The red dashed line indicates the mean difference, and the blue dashed lines represent the 95% limits of agreement (mean ± 1.96 SD). Higher variability is observed particularly at mean PSA concentrations above 6 ng/ml. Note that values above 15 ng/ml (n = 4) were analysed separately and are not shown in this plot.
Fig 4.
Bland-Altman plot illustrating the differences (capillary – venous) between paired measurements of free PSA against their mean values.
The red dashed line represents the mean difference, while the blue dashed lines indicate the 95% limits of agreement (mean ± 1.96 SD). Variability was predominantly observed at lower concentrations, with most measurements within the limits of agreement.