NakedSignal

Change explorer · Haematology and immunology

Point-of-care white cell count vs a central laboratory haematology analyser

Public dataA public method-comparison deposit, not a laboratory's data. Systems are described generically; the source names them.

Central lab haematology analyser replaced by point of care haematology analyser: 197 paired results from a published study by Shean and Bennett (2026), re-analysed by NakedSignal as if the study were one laboratory. At 4, 11 ×10⁹/L, 15 results changed category after the change, against about 6 expected from repeat testing alone.

run 25 September 2026 · config 6eb23df45893 · run file sha256 5586cd892ef1

Haematology and immunology

White cell count, ×10⁹/L

Central lab haematology analyser replaced by Point of care haematology analyser. 197 paired results.

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Comparison line

The new system reads 6.6% lower than the old system on average. The comparison line has a slope of 0.991 (95% interval 0.975 to 1.01) and an intercept of -0.378.

Public data
Comparison line, white cell count (×10⁹/L)Comparison line with slope 0.991 (95% interval 0.975 to 1.01) and intercept -0.378, drawn against the line of no change. Decision limits drawn at 4, 11 ×10⁹/L. Where the comparison line sits above the line of no change, the new system reads higher; below, lower.510510411No 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 (4, 11 ×10⁹/L). Dots mark where each line meets each limit; the gap between them is the bias at that limit.

run 25 September 2026 · config 6eb23df45893 · run file sha256 5586cd892ef1

Crossing each limit

Results that moved across a decision limit when the new system 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 (4, 11 ×10⁹/L)

Crossed after the change: 15

Expected from repeat testing alone: about 6

Grade and warnings

  • Re-test band: full (at least the protocol minimum of pairs).
  • Band half-width around each limit: 8.4%.
  • Results re-tested on data the band was not fitted to, median: 14%.
  • Share of the excess crossings caught on unseen data, comparison line and band together: 114%; comparison line alone: 79%. The excess is the crossings above what repeat testing alone would cause, so the share can exceed 100% or fall below zero.
  • Repeat-test imprecision: assumed, not measured at this site.

Source

Shean RC, Bennett ST (2026). Clinical Evaluation of a Novel Point-of-Care Hematology Analyzer for Complete Blood Count With Differential. Int J Lab Hematol. doi:10.1111/ijlh.70032 (opens in a new tab); PMC12956494 (opens in a new tab). Licence: CC BY 4.0 (opens in a new tab). Changes: Paired results re-analysed by NakedSignal's program; instruments described generically; only derived results are shown. The deposit names the systems.

Show the numbers
All values for white cell count, Central lab haematology analyser to Point of care haematology analyser
FieldValue
Paired results used197
Comparison line slope0.990539
Slope, 95% interval0.974753 to 1.009846
Comparison line intercept-0.377652
Mean difference, new minus old, as % of old-6.605
Decision limits (×10⁹/L)4, 11
Crossed after the change15
Expected from repeat testing alone6.11
Band half-width (%)8.4
Re-tested, unseen data, median (%)14.47
Re-tested, unseen data, range (%)11.17 to 15.74
Excess caught, line and band (%)113.77
Excess caught, line alone (%)78.78

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