Also known as a
Levey-Jennings chart, this is prepared by conducting a number of per-protocol runs of the assay (normally, to provide a minimum of 20 replicate measurements for each control material, over a period of at least 10 days, and ideally with different operators).
This SD plus the new mean can be used with confidence in setting up the
Levey-Jennings chart for the new lot of control.
The
Levey-Jennings chart remains a staple of laboratory QC.
The primary tracking method was the
Levey-Jennings chart for graphing the analytical results.
The control system includes the control materials, the mean and standard deviation used to set the
Levey-Jennings chart, and the process control rules applied.
The probability of the multirule procedure for error detection is much improved over the use of the
Levey-Jennings chart having a [+ or -]3 SD limit for determining acceptability of QC data.
The quantitative control results would also be plotted on a
Levey-Jennings chart and observed for shifts, trends, and outliers.
Regardless of how the control limits are established, a
Levey-Jennings chart still operates as a statistical control.
For example, the computer might be told that the desired sequence is to enter quality control data; view the computer-calculated mean, standard deviation, and coefficient of variation; save those statistics; produce a
Levey-Jennings chart; go back to the chart if you want to change values on it; and repeat the procedure for the next batch of QC data.
Levey-Jennings charts for 2 QCsamples (QC1/QC2) for 6 signature peptides (AKPAL, apo A-I; FPEVD, apo B; TPDVS, apo C-I; ESLSS, apo C-II; GWVTD, apo C-III; and LGPLV, apo E).
Mention is made of
Levey-Jennings charts and Westgard Rules but there is really no mention of how to use these tools in the context of day-to-day blood gas laboratory operation.
GloCyte uses disposable test cartridges, ensuring no sample carryover and easy disposal, and it includes built-in quality control using
Levey-Jennings charts and an audit table.
