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Change explorer · Haematology and immunology

Platelet count between two haematology analysers, impedance vs impedance

Public dataBuilt from a published open-access study.

Haematology analyser A, impedance platelet count compared with haematology analyser B, impedance platelet count: 21 paired results from a published study by Xiong et al. (2026), re-analysed by NakedSignal as if one laboratory had switched from the first system to the second. At 100, 150 ×10⁹/L, 0 results fall in a different category on the second system than on the first, against about 0.04 expected from repeat testing alone. Here the count sits below the repeat-testing expectation, but that expectation uses a default repeat-test imprecision, which can overstate repeat-testing noise, and the count cannot be told apart from what repeat testing alone would move, so it is not evidence of fewer than noise. A laboratory’s own measured imprecision decides. The 21 samples were selected from patients with pseudothrombocytopenia, so the numbers describe that group, not a general patient population.

Haematology and immunology

Platelet count, ×10⁹/L

Haematology analyser A, impedance platelet count compared with Haematology analyser B, impedance platelet count. 21 paired results.

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Comparison line

The new system reads 3.9% higher than the old system on average. The comparison line (Passing-Bablok) has a slope of 0.924 (95% interval 0.869 to 1.145) and an intercept of 0.971.

Public data
Comparison line, platelet count (×10⁹/L)Comparison line with slope 0.924 (95% interval 0.869 to 1.145) and intercept 0.971, drawn against the line of no change. Decision limits drawn at 100, 150 ×10⁹/L. Where the comparison line sits above the line of no change, the new system reads higher; below, lower.5010015050100150100150No changeComparison lineOld system, ×10⁹/LNew system, ×10⁹/L

Fig. 1. The comparison line against the line of no change, over the range of the decision limits (100, 150 ×10⁹/L). Dots mark where each line meets each limit; the gap between them is the bias at that limit.

Crossing each limit

Results that fall on the other side of a decision limit on the new system than on the old, read as if the new system had replaced the old, against the number repeat testing on one unchanged system would move. The program reports the count across all limits together.

All decision limits together (100, 150 ×10⁹/L)

Crossed between the two systems: 0

Expected from repeat testing alone: about 0.04

Grade and warnings

  • Re-test band not computed: 21 usable pairs, fewer than 40.
  • Repeat-test imprecision: default value.

Source

Xiong L, Pan X, Peng M, Gan T, Deng C, Zha H, Wang Y (2026). Evaluation of pre-dilution combined with optical/fluorescent platelet counting for correcting pseudothrombocytopenia. Front Med (Lausanne). doi:10.3389/fmed.2026.1855339 (opens in a new tab); PMC13395694 (opens in a new tab). Licence: CC BY 4.0 (opens in a new tab). Re-analysed by NakedSignal. The deposit names the systems.

Show the numbers
All values for platelet count, Haematology analyser A, impedance platelet count to Haematology analyser B, impedance platelet count
FieldValue
Paired results used21
Comparison line slope0.924419
Slope, 95% interval0.869078 to 1.145299
Comparison line intercept0.97093
Mean difference, new minus old, as % of old3.879
Decision limits (×10⁹/L)100, 150
Crossed between the two systems0
Expected from repeat testing alone0.04
Band half-width (%)none
Re-tested, unseen data, median (%)none
Re-tested, unseen data, range (%)none
Excess caught, line and band (%)none
Excess caught, line alone (%)none

Related

Other comparisons from the same study:

Guide: Crossings by chance

Every study behind the explorer, with its licence: public data. How the counts are made: how it works.

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