Comparison of paper-based transaminase test results to automated test results.

<p>(A) Bin placement accuracy. Nurse 1 (left table) and Nurse 2 (right table) visual device results (classified by “bin,” i.e. Bin 1 = <3x ULN [0–119 U/L], Bin 2 = 3–5x ULN [120–200 U/L], and Bin 3 = >5x ULN [>200 U/L]) were compared with automated device results (ALT Lab, also classified by bin) as the gold standard. Colored boxes indicate result pairs in which the visual result was in the same bin as the automated result (green, “correct”), a higher bin than the automated result (yellow, “overcall”), or a lower bin than the automated result (red, “undercall”). Per-bin accuracy for visual reading (Results) was calculated by dividing the number of correctly binned samples in each bin by the total number of samples in that bin. Overall bin placement accuracy (Results) was defined as the overall percentage of visual device results which fell in the same bin as the paired automated result. (B) Direct comparison of Nurse 1 (left plot, ALTN1) and Nurse 2 (right plot, ALTN2) visual device results to automated test results (ALTLab) for each subject. In each plot, the black diagonal line corresponds to the line of equality; the green diagonal lines correspond to +/−40 U/L from the line of equality; and the blue boxes represent ALT bins within which values for both the paper-based device and the automated method are within the same range: <3x ULN (0–119 U/L), 3 to 5x ULN (120–200 U/L), or >5x ULN (>200 U/L). (C) Reanalysis of the bin placement results (Nurse 1, left table; Nurse 2, right table) using a binary cutoff creating only two bins (<120 U/L = low, ≥120 U/L = high), as might be used in a “triage” or “screening” use scenario. (ALT = alanine aminotransferase. ULN = upper limit of normal).