CLSI EP31
Verification of Comparability of Patient Results Within One Health Care System
This document offers essential guidance on verifying the comparability of quantitiative laboratory results for individual patients within a health care system. By following the procedures outlined, medical laboratories can ensure consistent and reliable test results, ultimately enhancing patient care and safety.
This reaffirmed document has been reviewed and confirmed as suitable to remain published without revision to content, as of January 2017.
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{{FormatPrice(nonMemberPrice)}} List PriceClinical and Laboratory Standards Institute document EP31-A-IR—Verification of Comparability of Patient Results Within One Health Care System; Approved Guideline (Interim Revision) provides guidance on how to verify comparability of quantitative laboratory results for individual patients across a health care system. For the purpose of this document, a health care system is defined as a system of physician offices, clinics, hospitals, and reference laboratories, under one administrative entity, where a patient may present for laboratory testing, and whose results may be reviewed by any health care provider within the system for the purpose of providing medical care. This document does not provide guidance on how to correct method noncomparability that may be identified.
Interim Revision Changes to C54-A
Section 4
• A definition has been added for “standard deviation.”
Sections 8.2.1
• An explanation of the “range test” has been substituted for the “studentized range test” description.
Section 10.3
• A modified protocol for identifying an approximate analyte concentration to be used for the range test has been substituted. The new protocol requires knowledge of both total and within-run precision of the measurement system at the selected analyte concentration.
Section 10.7
• A description of how to calculate the critical difference for the range test has been included.
Sections 10.8
• A protocol for determining both the number of runs and number of replicates per run for the range test has been included.
Appendix A. Worked Examples
• Examples of how to use the document have been revised.
Appendix B. Tables of Runs, Replicates, and Range Rejection Limits
• New tables for use in determining both the number of runs and number of replicates per run for the range test have been included, as well as a description of how to use the tables.
Appendix C. Statistical Concepts
• C4. Range Test—The mathematical basis for the range test replaces Section C4 of the prior version of the document.
• C5. Within-run vs Total Standard Deviation—A description of the components of the precision of a measurement system are provided to elucidate the need for two runs when between-run imprecision makes up a significant proportion of total SD. This replaces Section C5 of the prior version of the document.
• C6. Number of Replicates—This section was eliminated.
• C7. Power Curves—This section was eliminated.
• C8. Comparative Power of Test Procedures—This section was eliminated.
Summary of Consensus and Delegate Comments and Subcommittee Responses
• The Summary of Consensus and Delegate Comments and Subcommittee Responses was removed as part of this interim revision. This summary is on file at the CLSI office and available upon request by contacting CLSI at 610.688.0100 or standard@clsi.org.
This document provides guidance on how to verify comparability of quantitative laboratory results for individual patients within a health care system. For the purpose of this document, a health care system is defined as a system of physician offices, clinics, hospitals, and reference laboratories, under one administrative entity, where a patient may present for laboratory testing, and whose results may be reviewed by any health care provider within the system for the purpose of providing medical care.
EP31 provides a simple approach to be used for the assessment of patient laboratory result comparability across a maximum of 10 instruments, and assumes that a more comprehensive validation of quantitative measurement system comparability has been undertaken when the measurement systems were initially introduced into the laboratory. A more comprehensive comparison among measurement procedure results can follow a methodology such as that described in CLSI document EP09.1 Comparability testing is just one facet of a program for assuring quality laboratory performance and is not intended to be a substitute for other quality monitors. This document does not address corrective action should method noncomparability be identified.
The approach described can also be used to verify comparability of patients’ results in situations such as those following reagent or calibrator lot changes, instrument component changes or maintenance procedures, alerts from QC or external quality assessment (EQA) (proficiency testing [PT]) events, or other special cause event.
This document is available in electronic format only.
A CLSI-IFCC joint project.
CLSI EP31IG
Free
Clinical and Laboratory Standards Institute document EP31-A-IR—Verification of Comparability of Patient Results Within One Health Care System; Approved Guideline (Interim Revision) provides guidance on how to verify comparability of quantitative laboratory results for individual patients across a health care system. For the purpose of this document, a health care system is defined as a system of physician offices, clinics, hospitals, and reference laboratories, under one administrative entity, where a patient may present for laboratory testing, and whose results may be reviewed by any health care provider within the system for the purpose of providing medical care. This document does not provide guidance on how to correct method noncomparability that may be identified.
Interim Revision Changes to C54-A
Section 4
• A definition has been added for “standard deviation.”
Sections 8.2.1
• An explanation of the “range test” has been substituted for the “studentized range test” description.
Section 10.3
• A modified protocol for identifying an approximate analyte concentration to be used for the range test has been substituted. The new protocol requires knowledge of both total and within-run precision of the measurement system at the selected analyte concentration.
Section 10.7
• A description of how to calculate the critical difference for the range test has been included.
Sections 10.8
• A protocol for determining both the number of runs and number of replicates per run for the range test has been included.
Appendix A. Worked Examples
• Examples of how to use the document have been revised.
Appendix B. Tables of Runs, Replicates, and Range Rejection Limits
• New tables for use in determining both the number of runs and number of replicates per run for the range test have been included, as well as a description of how to use the tables.
Appendix C. Statistical Concepts
• C4. Range Test—The mathematical basis for the range test replaces Section C4 of the prior version of the document.
• C5. Within-run vs Total Standard Deviation—A description of the components of the precision of a measurement system are provided to elucidate the need for two runs when between-run imprecision makes up a significant proportion of total SD. This replaces Section C5 of the prior version of the document.
• C6. Number of Replicates—This section was eliminated.
• C7. Power Curves—This section was eliminated.
• C8. Comparative Power of Test Procedures—This section was eliminated.
Summary of Consensus and Delegate Comments and Subcommittee Responses
• The Summary of Consensus and Delegate Comments and Subcommittee Responses was removed as part of this interim revision. This summary is on file at the CLSI office and available upon request by contacting CLSI at 610.688.0100 or standard@clsi.org.
This document provides guidance on how to verify comparability of quantitative laboratory results for individual patients within a health care system. For the purpose of this document, a health care system is defined as a system of physician offices, clinics, hospitals, and reference laboratories, under one administrative entity, where a patient may present for laboratory testing, and whose results may be reviewed by any health care provider within the system for the purpose of providing medical care.
EP31 provides a simple approach to be used for the assessment of patient laboratory result comparability across a maximum of 10 instruments, and assumes that a more comprehensive validation of quantitative measurement system comparability has been undertaken when the measurement systems were initially introduced into the laboratory. A more comprehensive comparison among measurement procedure results can follow a methodology such as that described in CLSI document EP09.1 Comparability testing is just one facet of a program for assuring quality laboratory performance and is not intended to be a substitute for other quality monitors. This document does not address corrective action should method noncomparability be identified.
The approach described can also be used to verify comparability of patients’ results in situations such as those following reagent or calibrator lot changes, instrument component changes or maintenance procedures, alerts from QC or external quality assessment (EQA) (proficiency testing [PT]) events, or other special cause event.
This document is available in electronic format only.
A CLSI-IFCC joint project.