Westgard rules control chart rules levey jennings chart. Reevaluation of the power of error detection of westgard. Westgard based on statistical concepts a combination of decision criteria or rules to assess if a system is in control use when at least 2 levels of control are run with the examination run cannot use with only one control dr. Selecting multirule quality control procedures based on. Westgards rules can be divided into withinrun rules, where the data for decisionmaking are available from within one qc run, and crossrun rules, where data from more than one qc. Pdf a multirule shewhart chart for quality control in clinical. Quality assurance in the diagnostic virology and serology. Westgard rules are used with levey jennings charts in laboratories. James westgard untuk mengevaluasi kontrol kualitas laboratorium kesehatan. Clinical labs have used the westgard rules for years, and labs routinely apply the six. Design and evaluation of statistical control procedures. Remember that multirule qc is a concept and that the westgard rules combination illustrated here is just an example of how that concept can be applied.
The latest advance in multirule qc procedures, westgard sigma rules brings together the power of six sigma metrics and westgard rules. You cant rely on just a 10x rule for qc, for instance, or build a 22s8x multirule combination. Instinctively you know that good multirule westgard rules and how to use them. A run is rejected when a single control measurement exceeds the mean plus 3s or the mean minus 3s control limit. Westgard rules news newspapers books scholar jstor june 2019 the westgard rules are a set of rules used for laboratory quality control. Westgard rules in hematology used for the wrong purpose. Westgard rules are multirule qc rules to help analyze whether or not an analytical run is incontrol or outofcontrol. Sitting down with james westgard, emeritus professor in pathology and laboratory medicine at the university of wisconsin medical school and. Pdf the multirules system for optimizing assay error detection originally developed. Westgard rules disclosures for past, present, and future. Westgard rule 22s, laboratory continuing education. The original multirule paper appeared in 1981 in the journal clinical chemistry 273, pp. This video discusses the westgard rules, which decide whether an analytical run is incontrol or outofcontrol. This westgard multirule system requires running two controls of different target values for each set of examinations, developing a leveyjennings chart for each, and applying the rules.
Westgard rules in hematology detect systematic errors and confuse the identification of random errors. The leveyjennings charts can be interpreted using the westgard rules. Here are some worksheets that describe the classic set of multirule procedures that came to be popularly known as westgard rules. They are a ed set of modified western electric rules, developed by james westgard and provided in. This work led to the multirule control procedure, internationally known as westgard rules. Terdapat 6 aturan dasar yang bisa digunakan secara terpisah atau kombinasi untuk mengevaluasi kualitas analitik suatu pemeriksaan. These rules were applied to laboratory qc by a clinical chemist named james westgard. The westgard rules require that target values and limits are created in the individual laboratory and depend on external quality assessment for harmonization. Using the sigmametric to benchmark the analytical performance of a test, the westgard sigma rules then provide a simplified recommendation on how many controls to run, how many westgard rules to implement, and now, for the first time, how often to run qc. Pdf a multirule shewhart chart for quality control in.
Four points abovebelow 1 sigma 4 1s or two points in a row with one above and one below 2 sigma r4s. However, because the value for control 1 is okay, westgard rules pdf dc, 1986, pp. If method performance is bad, no amount of are also available online. I have done some searches on the internet and on in regards to the westgard rules. They use a combination of traditional rules and some unique rules not used in other rule sets.
Qc procedure what is a multirule qc procedure first a. The operational enhancements included the addition of the auxiliary refrigerated calibrators, controls, and stats arccs module to the sampler and the integration of a new qc program, the westgard multirule shewhart quality control procedure, into the rp. Traditional westgard rules control data incontrol report data outofcontrol, reject a n alytical run 12s one point out of 2 sd s one point outside 3 sd 22s across runs 2 consecutive values outside the same 2 sd or within run 2 consecutive values outside the same 2 sd. Six sigmabased quality control abbott core laboratory. Westgard rules individual values are tested to determine if they are in, or out, of control using a set of five rules called the westgard rules after their originator. Sr4 represents a set of single wide control limits 3 sd with 4 control measurements. Westgard rules adalah aturan dasar yang diterbitkan pada tahun 1981 oleh dr. A computer program must be explicitly remember that multirule qc is a concept and that the westgard rules combination told how to interpret the rules. Quality control in clinical biochemistry linkedin slideshare. Westgards rules can be divided into withinrun rules, where the data for. Interpret the chart what is it telling you about the lab test.
Laboratory quality management system lqms training toolkit. R 4s the range difference between two controls within a run. These rules indicate which rows in a variable column of numbers are out ofcontrol. Everything you ever wanted to know, or possibly didnt want to know, about multirule qc. For im immunochemistry, 17 81% hospitals chose a 2sd rule, one 5% chose 3 sd, and three 14% chose some permutation of the westgard rules. Rules of thumb 6 sigma process single rule qc with 3.
These rules are used individually or in combination multirule tothese rules are used. Multirules are popularly known in the laboratory as westgard rules. If two controls are used, the westgard rules that may be considered for rejecting an analytical run are. This background variation causes false westgard rules pdf. A multirule shewhart chart for quality control in clinical chemistry. Can anybody on this site recommend a good text that either deals solely with the westgard rules or is a section of a qc book that also discusses the shewart control charts etc. The wellknown westgard multirule qc procedure uses 5 different control rules to judge the acceptability of an analytical run. The multirules system for optimizing assay error detection originally developed by james westgard and others is now widely used in clinical pathology. Managing the quality and productivity of analytical processes. Westgard and others published a multirule shewhart chart for quality control in clinical chemistry find, read and. Westgard rules include western electric rules 1, 2, and 4 and nelsons rule 5. Two of the major features of the smac ii system were operational ease and new multirule qc programs.
It is only applied when the iqc is tested in duplicate. Here are some worksheets that describe the classic set of multirule procedures. For example, if three control materials are to be analyzed, it is might be better to construct a multirule procedure from rules such as 1 3s, 2of3. Mr4 represents a standard set of westgard rules multirule qc procedure with 2 control measurements. Here are some worksheets that describe the classic set of multirule procedures that came to be. With permission of clinical chemistry, we are happy to be able to make the original multirule paper available. Sensitive to random error control rules westguard multirule chart 43. Westgard multirule r4s merupakan penolakan menggambarkan kesalahan random yaitu.
To explain the westgard rule control rules of quality control in detail. In the last two decades, updated versions of westgard rules have been released. Calculation of mean and standard deviation pdf, 56kb. The worksheets make clear how the rules fit together. Westgard and others published a multirule shewhart chart for quality control in clinical chemistry find, read and cite all the research you need on researchgate. Sensitive to random error control rules westguard multirule chart 42. The latest advance in multirule qc procedures, westgard sigma rules brings together. In our continuing efforts to simplify the selection of appropriate sqc procedures, we have recently introduced a new graphic tool called westgard sigma rules. This rule is violated when the difference in sd between the duplicates exceeds 4sd. In the 2017 westgard global qc survey, a little over half of labs 55% reported using 2 sd control rules.
Pdf reevaluation of the power of error detection of westgard. Just as the original set of westgard rules were neither patented nor commercially exclusive, so too are these new versions available free to the public. Quantitative qcmodule 7 1 westgard multirule system a multirule system developed by dr. By comparison, a singlerule qc procedure uses a single criterion or single set of control limits, such as a leveyjennings chart with control limits set as either the mean plus or minus 2 standard deviations 2s or. There is a 10x rule violation across runs and across errors, and control rules that pick up systematic errors better than random errors. But also included are two multirule combinations that may be considered more modern and appropriate to todays different testing capabilities and needs.
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