OPEN ACCESS pISSN 2234-3806
eISSN 2234-3814

Table. 3.

Sigma metrics and control rules for IQC of URSTs derived from each level of control material across all lots (N=856)

Analyte Level Grade Mean SD CV (%) TEa Sigma metric Control rules Pfr Ped Nc R
RBC 1 – −0.68 3.11 460.56 19.00 6.11 13.5s < 0.01 > 0.89 2 1
2 3+ 123.85 8.84 7.14 31.50 3.56 13s/22s/R4s/41s/8x 0.03 0.94 4 2
Bilirubin 1 – −0.62 2.18 352.32 14.50 6.64 13.5s < 0.01 > 0.96 3 1
2 – 1.76 1.93 109.5 14.50 7.5 13.5s < 0.01 > 0.96 3 1
3 3+ 73.66 3.87 5.25 14.50 3.75 12.5s 0.06 0.91 6 1
Urobilinogen 1 ± −0.07 2.65 3,972.33 12.00 4.54 12.5s 0.04 0.98 4 1
2 ± 3.03 1.94 63.99 12.00 6.19 13.5s < 0.01 > 0.89 2 1
Ketone 1 – 0.30 1.89 621.45 13.00 6.89 13.5s < 0.01 > 0.89 2 1
2 3+ 73.08 3.93 5.38 15.00 3.82 13s/22s/R4s/41s/8x 0.03 0.98 4 2
Protein 1 – −2.07 3.27 158.12 18.50 5.65 13.5s < 0.01 > 0.96 3 1
2 – 11.66 2.52 21.57 18.50 7.35 13.5s < 0.01 > 0.96 3 1
3 3+ 94.21 3.62 3.84 21.00 5.81 13.5s < 0.01 > 0.96 3 1
Glucose 1 – −1.01 5.94 587.91 77.50 13.05 13.5s < 0.01 > 0.89 2 1
2 3+ 235.63 9.69 4.11 65.00 6.71 13.5s < 0.01 > 0.89 2 1
Leukocytes 1 – −0.79 2.76 351.21 16.00 5.79 13.5s < 0.01 > 0.89 2 1
2 3+ 74.06 5.49 7.41 16.50 3.01 13s/22s/R4s/41s/8x 0.03 0.63 4 2
pH 1 5 18.43 0.81 4.40 15.00 18.51 13.5s < 0.01 > 0.89 2 1
2 7.5 121.13 21.7 17.91 42.50 1.96 13s/22s/R4s/41s/8x 0.03 0.05 4 2

Abbreviations: IQC, internal quality control; URST, urine reagent strip test; TEa, total allowable error; Pfr, probability of false rejection; Ped, probability of error detection; Nc, number of control measurements made; R, number of runs over which the control rules are applied; RBC, red blood cells.
Ann Lab Med 2021;41:447~454 https://doi.org/10.3343/alm.2021.41.5.447

© Ann Lab Med

© Korean Society for Laboratory Medicine. / Powered by INFOrang Co., Ltd