NakedSignal

Change explorer · Chemistry

LDL cholesterol by the Friedewald equation vs directly measured LDL

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

Central lab analyser, directly measured LDL cholesterol replaced by lDL cholesterol calculated by the Friedewald equation: 1,298 paired results from a published study by Dintshi et al. (2022), re-analysed by NakedSignal as if the study were one laboratory. No decision limits are configured for LDL cholesterol in mg/dL (from mmol/L x 38.67), so this comparison shows the comparison line and the average difference only.

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

Chemistry

LDL cholesterol, mg/dL (from mmol/L x 38.67)

Central lab analyser, directly measured LDL cholesterol replaced by LDL cholesterol calculated by the Friedewald equation. 1,298 paired results.

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Comparison line

The new system reads 14.7% lower than the old system on average. The comparison line has a slope of 0.962 (95% interval 0.949 to 0.974) and an intercept of -7.529.

No decision lines configured for this analyte and unit; comparison only (no switch table, no re-test band)

Crossing each limit

No crossing count: the program had no decision limits for this comparison.

Grade and warnings

  • No decision lines configured for this analyte and unit; comparison only (no switch table, no re-test band)
  • A secondary comparison: a calculated value against a measured one, shown for completeness.

Source

Dintshi M, Kone N, Khoza S (2022). Comparison of measured LDL cholesterol with calculated LDL-cholesterol using the Friedewald and Martin-Hopkins formulae in diabetic adults at Charlotte Maxeke Johannesburg Academic Hospital/NHLS Laboratory. PLoS One. doi:10.1371/journal.pone.0277981 (opens in a new tab); PMC9749991 (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 LDL cholesterol, Central lab analyser, directly measured LDL cholesterol to LDL cholesterol calculated by the Friedewald equation
FieldValue
Paired results used1,298
Comparison line slope0.96225
Slope, 95% interval0.949346 to 0.973786
Comparison line intercept-7.528733
Mean difference, new minus old, as % of old-14.7
Decision limits (mg/dL (from mmol/L x 38.67))none
Crossed after the changenone
Expected from repeat testing alonenone
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: Bias at clinical decision limits

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

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