NakedSignal
Write to us

Change explorer · Haematology and immunology

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

Public dataBuilt from a published open-access study.

Central lab haematology analyser compared with point of care haematology analyser: 197 paired results from a published study by Shean and Bennett (2026), re-analysed by NakedSignal as if one laboratory had switched from the first system to the second. At 4, 11 ×10⁹/L, 15 results fall in a different category on the second system than on the first, against about 6 expected from repeat testing alone. That expected count uses a default repeat-test imprecision, the setting our program uses when no precision data are supplied, not one measured in this study, so the two numbers are not a test of whether the switch moves more results than repeat testing would.

Haematology and immunology

White cell count, ×10⁹/L

Central lab haematology analyser compared with Point of care haematology analyser. 197 paired results.

Compare it with the other comparisons in the explorer

Comparison line

The new system reads 6.6% lower than the old system on average. The comparison line (Passing-Bablok) has a slope of 0.991 (95% interval 0.975 to 1.008) 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 1.008) 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.

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 (4, 11 ×10⁹/L)

Crossed between the two systems: 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: 113%; 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: default value.

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). Re-analysed by NakedSignal. 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% interval0.97487 to 1.007534
Comparison line intercept-0.377652
Mean difference, new minus old, as % of old-6.605
Decision limits (×10⁹/L)4, 11
Crossed between the two systems15
Expected from repeat testing alone6.11
Band half-width (%)8.4
Re-tested, unseen data, median (%)14.47
Re-tested, unseen data, range (%)13.2 to 15.74
Excess caught, line and band (%)113.38
Excess caught, line alone (%)78.78

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.

Changing a system like this one?

Request a first site report