Difference between revisions of "Quality"
m (→See also) |
|||
(62 intermediate revisions by the same user not shown) | |||
Line 1: | Line 1: | ||
'''Quality''', in pathology, has got a lot of attention lately because there have been high profile | '''Quality''', in pathology, has got a lot of attention lately because there have been high-profile irregularities that lead to significant harm.<ref>URL: [http://www.attorneygeneral.jus.gov.on.ca/inquiries/goudge/index.html http://www.attorneygeneral.jus.gov.on.ca/inquiries/goudge/index.html]. Accessed on: 1 March 2011.</ref><ref>Judicial inquiry probes faulty breast cancer tests. CBC website. URL: [http://www.cbc.ca/news/background/cancer/inquiry.html http://www.cbc.ca/news/background/cancer/inquiry.html]. Accessed on: 30 January 2012.</ref> | ||
= | =General= | ||
The keys to ''quality'' are: | |||
#Understanding the needs of the stakeholders (surgeons, oncologists, patients, other pathologists, the public at large). | |||
#Understanding the processes. | |||
#Developing measures of quality. | |||
#Tracking the measures of quality & assessing their validity. | |||
#Understanding the causes of failures/adverse events in the context of the processes. | |||
#Continually doing all of the above with the aim of improving outcomes - continuous quality improvement. | |||
A | =Definitions= | ||
==System documentation and description== | |||
Quality Management Program-Laboratory Services (QMP-LS) defines a hierarchy of documentation:<ref name=qmpls_org>URL: [http://www.qmpls.org/LaboratoryAccreditation/OLAActivitiesEducationalTools/OLAPresentations/tabid/111/id/11/Default.aspx) http://www.qmpls.org/LaboratoryAccreditation/OLAActivitiesEducationalTools/OLAPresentations/tabid/111/id/11/Default.aspx)]. Accessed on: 18 April 2012.</ref> | |||
*Policy. | |||
*Process | |||
*Procedures. | |||
===Policy=== | |||
*High level document | |||
*Describes rationale for processes, defines goals/objectives - includes parameters that can be measured. | |||
===Process=== | |||
*Intermediate level document. | |||
*Defines input and outputs, outlines the steps taken to achieve an objective - should ''not'' be overly detailed. | |||
===Procedure=== | |||
*Low level document. | |||
*Detailed line-by-line instructions - description of the workflow. | |||
==Other== | |||
===Quality control=== | |||
*Examines whether a process is hitting its target(s) for its measure(s) of quality. | |||
In short: ''Does it hit the targets?'' | |||
===Quality assurance=== | |||
*Program to insure that a process is yielding the desired output(s). | |||
In short: ''Does it produce the desired output?'' | |||
=Analysis= | |||
===Overview=== | |||
Quality issues can be examined in a number of different ways. | |||
Finding a problem: | |||
*Root cause analysis. | |||
Anticipating problems: | |||
*Failure mode and effects analysis (FMEA). | |||
===General error analysis=== | |||
Pathology errors happen any time from when the lab gets the specimen until after the report is issued. | |||
When errors happen: | |||
*Work-up the problem. | |||
**Where did the error occur? Pathologist error? | |||
*Talk to the clinician. | |||
**If it is a ''[[critical diagnosis]]'' contact the most-responsible physician immediately... if they are unreachable call the physician on-call for the most-responsible physician... if the patient is out-of-town you may have to coordinate with the local emergency department. | |||
*Talk to the chief of pathology. | |||
*Incident report. | |||
*Reconstruct error. | |||
**Was it a specimen mix-up? | |||
***Is there another error? | |||
*Amend the report(s). | |||
*Remedy the source of error. | |||
====The classic structural break down==== | |||
A classic structural break down for error analysis is: | |||
{{familytree/start}} | {{familytree/start}} | ||
{{familytree | | | | | | | | | A01 | | | | | |A01=Errors in pathology}} | {{familytree | | | | | | | | | A01 | | | | | |A01=Errors in pathology}} | ||
Line 10: | Line 72: | ||
{{familytree | | | | B01 | | | B02 | | | B03|B01=Pre-analytical errors|B02=Analytical errors|B03=Post-analytical errors }} | {{familytree | | | | B01 | | | B02 | | | B03|B01=Pre-analytical errors|B02=Analytical errors|B03=Post-analytical errors }} | ||
{{familytree/end}} | {{familytree/end}} | ||
Note: | |||
*This break down is arbitrary and ''in of itself'' most useful for answering exam questions. | |||
*In a practical context, it is a frame work for classifying errors. It is ''not'' useful for understanding the source of an error or addressing it. | |||
====Pre-analytic errors==== | |||
*Container mix-up - pre-lab & in-lab. | |||
*Block mix-up. | |||
*Slide mix-up - labels wrong. | |||
*Poor quality slides (fixation, processing, staining). | |||
*Lost specimen - can be potentially anywhere in the process. | |||
====Analytic errors==== | |||
*Interpretation wrong. | |||
**Factors: | |||
***Difficult case. | |||
***Technical factors (quality of slides). | |||
***Lack of clinical history. | |||
====Post-analytic errors==== | |||
*Wrong case signed-out. | |||
*Filing problem/lost report. | |||
*Interpretation of report problem (poorly written report, misinterpretation). | |||
==Sources of error== | |||
*"Human error". | |||
**Training. | |||
**Work flow. | |||
*Process gaps. | |||
**Process control. | |||
**Lack of redundancy. | |||
==Types of errors== | |||
Can be subdivided into the following groups:<ref>{{Cite journal | last1 = Renshaw | first1 = AA. | title = Measuring and reporting errors in surgical pathology. Lessons from gynecologic cytology. | journal = Am J Clin Pathol | volume = 115 | issue = 3 | pages = 338-41 | month = Mar | year = 2001 | doi = 10.1309/M2XP-3YJA-V6E2-QD9P | PMID = 11242788 }}</ref> | |||
*False-negative - missed diagnosis. | |||
*False-positive - diagnosis made that on review considered not to be present. | |||
*Threshold - difference of opinion regarding a diagnostic threshold. | |||
*Type and grade. | |||
*Missed margin. | |||
*Other. | |||
==Grading of errors== | |||
May be subdivided by three groups: | |||
*Grade 1: no consequence. | |||
*Grade 2: possible consequence. | |||
*Grade 3: definitely a consequence. | |||
==Error reduction== | ==Error reduction== | ||
Line 23: | Line 131: | ||
*Clinical information entry required. | *Clinical information entry required. | ||
**Allow correlation with test. | **Allow correlation with test. | ||
***The interpretation may differ if the history says "screening coloscopy" versus "large cecal mass, anemia and weight loss". | ***The interpretation may differ if the history says "screening coloscopy" versus "large cecal mass, anemia and weight loss" versus "breast cancer". | ||
*The use of algorithms to guide decisions where applicable.<ref>Kahneman D. ["Als wären wir gespalten": Der Psychologe und Nobelpreisträger Daniel Kahneman über die angeborenen Schwächen des Denkens, trügerische Erinnerungen und die irreführende Macht der Intuition]. Der Spiegel. Nr. 21. 2012. URL: [http://www.spiegel.de/spiegel/print/index-2012-21.html http://www.spiegel.de/spiegel/print/index-2012-21.html].</ref> | |||
**Remove subjectivity. | |||
**Increase objectivity, reproducibility. | |||
==Dealing with diagnostic errors== | |||
*Opinion is split on whether reports should be ''amended'' or ''addended'' - see ''[[sign out]]'' article. | |||
=Measures of quality= | |||
Any number of parameters can be used to measure quality. The when, where and how-often something is measured depends on the value-added. | |||
===General measures of quality=== | |||
There are really only two: | |||
#Timeliness, i.e. turn-around time (TAT). | |||
#Error rate. | |||
Note: | |||
*1 and 2 can be examined/quantified in any number of ways. | |||
*''Error'', in the context of a measurement, has to be defined. | |||
===Internal measures of quality=== | |||
====Smaller categories==== | |||
Smaller categories - errors:<ref name=pmid19851132>{{Cite journal | last1 = Nakhleh | first1 = RE. | title = Core components of a comprehensive quality assurance program in anatomic pathology. | journal = Adv Anat Pathol | volume = 16 | issue = 6 | pages = 418-23 | month = Nov | year = 2009 | doi = 10.1097/PAP.0b013e3181bb6bf7 | PMID = 19851132 }}</ref> | |||
*Analytic: specimen identification & transport. | |||
*Preanalytic/analytic: [[tissue processing]], e.g. [[fixation]], blocking, embedding, sectioning, staining. | |||
*Analytic: interpretation. | |||
*Postanalytic: reporting/report integrity. | |||
=====Individual measures===== | |||
Specific measures:<ref name=pmid19851132/> | |||
*Preanalytic: | |||
**Identification - numbers match requisition. | |||
**Appropriate container. | |||
*Analytic: | |||
**Mislabeling. | |||
**Interpretation errors - based on: | |||
***Internal review. | |||
****Cytology-histology correlation. | |||
****Biopsy-resection correlation. | |||
****Frozen section-permanent section correlation. | |||
****Internal comparisons, e.g. ASCUS/LSIL between pathologists. | |||
***External review. | |||
****External standards/expected rate. | |||
**Amended reports - captures several of the above. | |||
*Postanalytic: | |||
**Completeness of report. | |||
**Critical diagnosis timely? | |||
**Report delivered to appropriate person? | |||
===External measures of quality=== | |||
====Benchmark==== | |||
*An external quality measure, i.e. a comparison to an outside group or agency. | |||
**Slides are sent around from an external source: | |||
***Lab has to stain 'em and send 'em back for an assessment. | |||
***Pathologists render diagnoses on 'em and are given the (externally rendered) consensus diagnosis. | |||
=Immunohistochemistry= | |||
{{Main|Immunohistochemistry}} | |||
===Classification of IHC tests=== | |||
IHC tests are classified in a paper by Torlakovic ''et al.'':<ref name=pmid20154273>{{Cite journal | last1 = Torlakovic | first1 = EE. | last2 = Riddell | first2 = R. | last3 = Banerjee | first3 = D. | last4 = El-Zimaity | first4 = H. | last5 = Pilavdzic | first5 = D. | last6 = Dawe | first6 = P. | last7 = Magliocco | first7 = A. | last8 = Barnes | first8 = P. | last9 = Berendt | first9 = R. | title = Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry: best practice recommendations for standardization of immunohistochemistry tests. | journal = Am J Clin Pathol | volume = 133 | issue = 3 | pages = 354-65 | month = Mar | year = 2010 | doi = 10.1309/AJCPDYZ1XMF4HJWK | PMID = 20154273 }}</ref> | |||
*''Class I'': | |||
**Results used by pathologists. | |||
**Adjunct to histomorphology. | |||
**Examples: CD45, S-100. | |||
*''Class II'': | |||
**Used by clinicans for treatment decisions. | |||
**Considered independent of the other information in the pathology report; thus, cannot be derived from other information in the report. | |||
**Examples: ER, PR, HER2, Ki-67, CD117, CD20. | |||
The implication of irregularies in the different classes are different. Problems in ''Class II'' tests are potentially more severe, as there is no internal control. | |||
===Work-up of suspected IHC problems=== | |||
*Review controls (internal and external). | |||
**Isolated to case vs. larger problem? | |||
***Discuss with lab/make other pathologists aware of the issue. | |||
*Repeat test - to identify the cause. | |||
IHC process: | |||
* | #Ischemia time - warm ischemia, preparation of specimen. | ||
#Fixation - under, over, defective fixative, not enough fixative. | |||
#Processing prior to antibody binding, usu. heating (antigen retrieval). | |||
#Antibody-antigen binding. | |||
#Reporter molecule binding. | |||
#Counterstaining. | |||
#Interpretation problem. | |||
#*Known/expected epitope cross-reactions, e.g. [[CMV]] & [[HSV]].<ref name=pmid3029407>{{Cite journal | last1 = Balachandran | first1 = N. | last2 = Oba | first2 = DE. | last3 = Hutt-Fletcher | first3 = LM. | title = Antigenic cross-reactions among herpes simplex virus types 1 and 2, Epstein-Barr virus, and cytomegalovirus. | journal = J Virol | volume = 61 | issue = 4 | pages = 1125-35 | month = Apr | year = 1987 | doi = | PMID = 3029407 | PMC = 254073 | | |||
URL = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC254073/?tool=pubmed }}</ref> | |||
#*Unknown/unexpected epitope cross-reactions. | |||
== | Notes: | ||
* | *Problems can arise at any step. | ||
** | |||
* | =Other= | ||
==Data retention standards== | |||
*There are data retention standards - how long results have to be retained. | |||
===College of American Pathologists=== | |||
*In the United States, there are standards from ''College of American Pathologists'' (CAP) and ''Clinical Laboratory Improvement Amendments'' (CLIA).<ref>URL: [http://www.cms.gov/clia/ http://www.cms.gov/clia/]. Accessed on: 1 April 2012.</ref> | |||
Selected CAP and CLIA standards:<ref>URL: [http://home.ccr.cancer.gov/lop/intranet/policymanual/generalpolicy/CAPCLIA.asp http://home.ccr.cancer.gov/lop/intranet/policymanual/generalpolicy/CAPCLIA.asp]. Accessed on: 1 April 2012.</ref> | |||
*Cytology slide (non-fine needle aspiration): 5 years from the exam date. | |||
*Fine needle aspiration: 10 years from the exam date. | |||
*Histopathology slides: 10 years from the exam date. | |||
===Canadian Association of Pathologists=== | |||
The Canadian standards are higher than the US ones. | |||
Summary of selected suggestions:<ref>URL: [http://cap-acp.org/guide_retention-human-biologic-material.cfm http://cap-acp.org/guide_retention-human-biologic-material.cfm]. Accessed on: 6 May 2012.</ref> | |||
{| class = "wikitable sortable" | |||
! Material | |||
! Origin | |||
! Suggested retention period | |||
! Additional notes | |||
|- | |||
| Wet tissue | |||
| surgical | |||
| 4 weeks after final report | |||
| - | |||
|- | |||
| Paraffin blocks | |||
| surgical | |||
| 20 years | |||
| 50 years for paediatric cases | |||
|- | |||
| Slides | |||
| surgical | |||
| 20 years | |||
| - | |||
|- | |||
| Wet tissue | |||
| autopsy | |||
| 3 months after final report | |||
| Coroners'/medical examiner cases may be longer | |||
|- | |||
| Paraffin blocks | |||
| autopsy | |||
| 10 years | |||
| Coroners'/medical examiner cases may be longer | |||
|- | |||
| Slides | |||
| autopsy | |||
| 10 years | |||
| Coroners'/medical examiner cases may be longer | |||
|- | |||
|} | |||
==Failure-potential analysis== | |||
Adapted from Ullman:<ref name=ullman>{{cite book |title=The mechanical design process |last= Ullman |first = David G. |authorlink= |coauthors= |year= 1997 |publisher= McGraw-Hill Companies Inc. |location= Toronto|isbn=0-07-065756-4 |page= |pages= |url= |accessdate=}}</ref> | |||
#Identify potential individual failures. | |||
#Identify the consequences of those failures. | |||
#Identify how the individual failures can arise. | |||
#Identify the corrective action. | |||
==Biopsy size== | ==Biopsy size== | ||
Very small tissue fragments are associated with a decreased diagnostic yield and an increased diagnostic uncertainty. | Very small tissue fragments are associated with a decreased diagnostic yield and an increased diagnostic uncertainty. | ||
==See also | =Quality standards organization= | ||
There are a large number of organizations that have written standards for quality in laboratory medicine. | |||
==International== | |||
===International standards organization=== | |||
*Abbreviated ''ISO''. | |||
Standard: | |||
*ISO 15189:2007.<ref>URL: [http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=42641 http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=42641]. Accessed on: 18 April 2012</ref>. | |||
**Published in 2007. Supersedes a standard published in 2003. | |||
Note: | |||
*Unfortunately one has to shell out money to get a peak at 'em. | |||
==United States of America== | |||
===Clinical laboratory improvement amendments=== | |||
*Abbreviated ''CLIA''. | |||
*Published a multitude of standards & guidelines.<ref>URL: [http://www.cms.hhs.gov/Regulations-and-Guidance/Legislation/CLIA/index.html?redirect=/clia/ http://www.cms.hhs.gov/Regulations-and-Guidance/Legislation/CLIA/index.html?redirect=/clia/]. Accessed on: 18 April 2012.</ref> | |||
===College of American Pathologists=== | |||
*Do laboratory accreditation.<ref>URL: [http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=laboratory_accreditation%2Faboutlap.html&_state=maximized&_pageLabel=cntvwr http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=laboratory_accreditation%2Faboutlap.html&_state=maximized&_pageLabel=cntvwr]. Accessed on: 18 April 2012.</ref> | |||
==Canada== | |||
===Canadian immunohistochemistry quality control=== | |||
*Abbreviated ''CIQC''. | |||
*[https://ciqc.ca/Pages/default.aspx CIQC webpage (ciqc.ca)] | |||
===Ontario=== | |||
*[[Institute for Quality Management in Healthcare]] - previously ''Quality Management Program - Laboratory Services''. | |||
**Set-up by the ''Ontario Medical Assocation''. | |||
==United Kingdom== | |||
*National Pathology Benchmarking Service (NPBS).<ref>URL: [http://www.keele.ac.uk/pharmacy/general/npbs/ http://www.keele.ac.uk/pharmacy/general/npbs/]. Accessed on: 18 April 2012.</ref> | |||
=See also= | |||
*[[Critical values]]. | *[[Critical values]]. | ||
*[[CAP checklists]]. | *[[CAP checklists]]. | ||
*[[Tissue floater]]. | |||
*[[Histology artifacts]]. | |||
*[[Waffle diagnosis]]. | |||
*[[Workload measurement]]. | |||
*[[Anatomical pathology laboratory processes]]. | |||
=References= | |||
{{Reflist|2}} | |||
== | =External links= | ||
*[http://www.keele.ac.uk/pharmacy/general/npbs/ UK national benchmarking (keele.ac.uk)]. | |||
*[http://www.westgard.com/westgard-rules-and-multirules.htm Multirule quality control - (westgard.com)] - statistical process control explained for the mathematically challenged. | |||
[[Category:Quality]] | [[Category:Quality]] |
Latest revision as of 17:27, 14 February 2017
Quality, in pathology, has got a lot of attention lately because there have been high-profile irregularities that lead to significant harm.[1][2]
General
The keys to quality are:
- Understanding the needs of the stakeholders (surgeons, oncologists, patients, other pathologists, the public at large).
- Understanding the processes.
- Developing measures of quality.
- Tracking the measures of quality & assessing their validity.
- Understanding the causes of failures/adverse events in the context of the processes.
- Continually doing all of the above with the aim of improving outcomes - continuous quality improvement.
Definitions
System documentation and description
Quality Management Program-Laboratory Services (QMP-LS) defines a hierarchy of documentation:[3]
- Policy.
- Process
- Procedures.
Policy
- High level document
- Describes rationale for processes, defines goals/objectives - includes parameters that can be measured.
Process
- Intermediate level document.
- Defines input and outputs, outlines the steps taken to achieve an objective - should not be overly detailed.
Procedure
- Low level document.
- Detailed line-by-line instructions - description of the workflow.
Other
Quality control
- Examines whether a process is hitting its target(s) for its measure(s) of quality.
In short: Does it hit the targets?
Quality assurance
- Program to insure that a process is yielding the desired output(s).
In short: Does it produce the desired output?
Analysis
Overview
Quality issues can be examined in a number of different ways.
Finding a problem:
- Root cause analysis.
Anticipating problems:
- Failure mode and effects analysis (FMEA).
General error analysis
Pathology errors happen any time from when the lab gets the specimen until after the report is issued.
When errors happen:
- Work-up the problem.
- Where did the error occur? Pathologist error?
- Talk to the clinician.
- If it is a critical diagnosis contact the most-responsible physician immediately... if they are unreachable call the physician on-call for the most-responsible physician... if the patient is out-of-town you may have to coordinate with the local emergency department.
- Talk to the chief of pathology.
- Incident report.
- Reconstruct error.
- Was it a specimen mix-up?
- Is there another error?
- Was it a specimen mix-up?
- Amend the report(s).
- Remedy the source of error.
The classic structural break down
A classic structural break down for error analysis is:
Errors in pathology | |||||||||||||||||||||||||||||||||
Pre-analytical errors | Analytical errors | Post-analytical errors | |||||||||||||||||||||||||||||||
Note:
- This break down is arbitrary and in of itself most useful for answering exam questions.
- In a practical context, it is a frame work for classifying errors. It is not useful for understanding the source of an error or addressing it.
Pre-analytic errors
- Container mix-up - pre-lab & in-lab.
- Block mix-up.
- Slide mix-up - labels wrong.
- Poor quality slides (fixation, processing, staining).
- Lost specimen - can be potentially anywhere in the process.
Analytic errors
- Interpretation wrong.
- Factors:
- Difficult case.
- Technical factors (quality of slides).
- Lack of clinical history.
- Factors:
Post-analytic errors
- Wrong case signed-out.
- Filing problem/lost report.
- Interpretation of report problem (poorly written report, misinterpretation).
Sources of error
- "Human error".
- Training.
- Work flow.
- Process gaps.
- Process control.
- Lack of redundancy.
Types of errors
Can be subdivided into the following groups:[4]
- False-negative - missed diagnosis.
- False-positive - diagnosis made that on review considered not to be present.
- Threshold - difference of opinion regarding a diagnostic threshold.
- Type and grade.
- Missed margin.
- Other.
Grading of errors
May be subdivided by three groups:
- Grade 1: no consequence.
- Grade 2: possible consequence.
- Grade 3: definitely a consequence.
Error reduction
Various strategies can be employed:[5]
- Training of staff - on error handling.
- Computer order entry.
- Avoid duplication fatigue.
- Quick correlation with several identifying features.
- Full name, sex, date of birth -- these all appear when one opens a case.
- Barcode use.
- Avoid transcription errors.
- Clinical information entry required.
- Allow correlation with test.
- The interpretation may differ if the history says "screening coloscopy" versus "large cecal mass, anemia and weight loss" versus "breast cancer".
- Allow correlation with test.
- The use of algorithms to guide decisions where applicable.[6]
- Remove subjectivity.
- Increase objectivity, reproducibility.
Dealing with diagnostic errors
- Opinion is split on whether reports should be amended or addended - see sign out article.
Measures of quality
Any number of parameters can be used to measure quality. The when, where and how-often something is measured depends on the value-added.
General measures of quality
There are really only two:
- Timeliness, i.e. turn-around time (TAT).
- Error rate.
Note:
- 1 and 2 can be examined/quantified in any number of ways.
- Error, in the context of a measurement, has to be defined.
Internal measures of quality
Smaller categories
Smaller categories - errors:[7]
- Analytic: specimen identification & transport.
- Preanalytic/analytic: tissue processing, e.g. fixation, blocking, embedding, sectioning, staining.
- Analytic: interpretation.
- Postanalytic: reporting/report integrity.
Individual measures
Specific measures:[7]
- Preanalytic:
- Identification - numbers match requisition.
- Appropriate container.
- Analytic:
- Mislabeling.
- Interpretation errors - based on:
- Internal review.
- Cytology-histology correlation.
- Biopsy-resection correlation.
- Frozen section-permanent section correlation.
- Internal comparisons, e.g. ASCUS/LSIL between pathologists.
- External review.
- External standards/expected rate.
- Internal review.
- Amended reports - captures several of the above.
- Postanalytic:
- Completeness of report.
- Critical diagnosis timely?
- Report delivered to appropriate person?
External measures of quality
Benchmark
- An external quality measure, i.e. a comparison to an outside group or agency.
- Slides are sent around from an external source:
- Lab has to stain 'em and send 'em back for an assessment.
- Pathologists render diagnoses on 'em and are given the (externally rendered) consensus diagnosis.
- Slides are sent around from an external source:
Immunohistochemistry
Classification of IHC tests
IHC tests are classified in a paper by Torlakovic et al.:[8]
- Class I:
- Results used by pathologists.
- Adjunct to histomorphology.
- Examples: CD45, S-100.
- Class II:
- Used by clinicans for treatment decisions.
- Considered independent of the other information in the pathology report; thus, cannot be derived from other information in the report.
- Examples: ER, PR, HER2, Ki-67, CD117, CD20.
The implication of irregularies in the different classes are different. Problems in Class II tests are potentially more severe, as there is no internal control.
Work-up of suspected IHC problems
- Review controls (internal and external).
- Isolated to case vs. larger problem?
- Discuss with lab/make other pathologists aware of the issue.
- Isolated to case vs. larger problem?
- Repeat test - to identify the cause.
IHC process:
- Ischemia time - warm ischemia, preparation of specimen.
- Fixation - under, over, defective fixative, not enough fixative.
- Processing prior to antibody binding, usu. heating (antigen retrieval).
- Antibody-antigen binding.
- Reporter molecule binding.
- Counterstaining.
- Interpretation problem.
Notes:
- Problems can arise at any step.
Other
Data retention standards
- There are data retention standards - how long results have to be retained.
College of American Pathologists
- In the United States, there are standards from College of American Pathologists (CAP) and Clinical Laboratory Improvement Amendments (CLIA).[10]
Selected CAP and CLIA standards:[11]
- Cytology slide (non-fine needle aspiration): 5 years from the exam date.
- Fine needle aspiration: 10 years from the exam date.
- Histopathology slides: 10 years from the exam date.
Canadian Association of Pathologists
The Canadian standards are higher than the US ones.
Summary of selected suggestions:[12]
Material | Origin | Suggested retention period | Additional notes |
---|---|---|---|
Wet tissue | surgical | 4 weeks after final report | - |
Paraffin blocks | surgical | 20 years | 50 years for paediatric cases |
Slides | surgical | 20 years | - |
Wet tissue | autopsy | 3 months after final report | Coroners'/medical examiner cases may be longer |
Paraffin blocks | autopsy | 10 years | Coroners'/medical examiner cases may be longer |
Slides | autopsy | 10 years | Coroners'/medical examiner cases may be longer |
Failure-potential analysis
Adapted from Ullman:[13]
- Identify potential individual failures.
- Identify the consequences of those failures.
- Identify how the individual failures can arise.
- Identify the corrective action.
Biopsy size
Very small tissue fragments are associated with a decreased diagnostic yield and an increased diagnostic uncertainty.
Quality standards organization
There are a large number of organizations that have written standards for quality in laboratory medicine.
International
International standards organization
- Abbreviated ISO.
Standard:
- ISO 15189:2007.[14].
- Published in 2007. Supersedes a standard published in 2003.
Note:
- Unfortunately one has to shell out money to get a peak at 'em.
United States of America
Clinical laboratory improvement amendments
- Abbreviated CLIA.
- Published a multitude of standards & guidelines.[15]
College of American Pathologists
- Do laboratory accreditation.[16]
Canada
Canadian immunohistochemistry quality control
- Abbreviated CIQC.
- CIQC webpage (ciqc.ca)
Ontario
- Institute for Quality Management in Healthcare - previously Quality Management Program - Laboratory Services.
- Set-up by the Ontario Medical Assocation.
United Kingdom
- National Pathology Benchmarking Service (NPBS).[17]
See also
- Critical values.
- CAP checklists.
- Tissue floater.
- Histology artifacts.
- Waffle diagnosis.
- Workload measurement.
- Anatomical pathology laboratory processes.
References
- ↑ URL: http://www.attorneygeneral.jus.gov.on.ca/inquiries/goudge/index.html. Accessed on: 1 March 2011.
- ↑ Judicial inquiry probes faulty breast cancer tests. CBC website. URL: http://www.cbc.ca/news/background/cancer/inquiry.html. Accessed on: 30 January 2012.
- ↑ URL: http://www.qmpls.org/LaboratoryAccreditation/OLAActivitiesEducationalTools/OLAPresentations/tabid/111/id/11/Default.aspx). Accessed on: 18 April 2012.
- ↑ Renshaw, AA. (Mar 2001). "Measuring and reporting errors in surgical pathology. Lessons from gynecologic cytology.". Am J Clin Pathol 115 (3): 338-41. doi:10.1309/M2XP-3YJA-V6E2-QD9P. PMID 11242788.
- ↑ Fabbretti, G. (Jun 2010). "Risk management: correct patient and specimen identification in a surgical pathology laboratory. The experience of Infermi Hospital, Rimini, Italy.". Pathologica 102 (3): 96-101. PMID 21171512.
- ↑ Kahneman D. ["Als wären wir gespalten": Der Psychologe und Nobelpreisträger Daniel Kahneman über die angeborenen Schwächen des Denkens, trügerische Erinnerungen und die irreführende Macht der Intuition]. Der Spiegel. Nr. 21. 2012. URL: http://www.spiegel.de/spiegel/print/index-2012-21.html.
- ↑ 7.0 7.1 Nakhleh, RE. (Nov 2009). "Core components of a comprehensive quality assurance program in anatomic pathology.". Adv Anat Pathol 16 (6): 418-23. doi:10.1097/PAP.0b013e3181bb6bf7. PMID 19851132.
- ↑ Torlakovic, EE.; Riddell, R.; Banerjee, D.; El-Zimaity, H.; Pilavdzic, D.; Dawe, P.; Magliocco, A.; Barnes, P. et al. (Mar 2010). "Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry: best practice recommendations for standardization of immunohistochemistry tests.". Am J Clin Pathol 133 (3): 354-65. doi:10.1309/AJCPDYZ1XMF4HJWK. PMID 20154273.
- ↑ Balachandran, N.; Oba, DE.; Hutt-Fletcher, LM. (Apr 1987). "Antigenic cross-reactions among herpes simplex virus types 1 and 2, Epstein-Barr virus, and cytomegalovirus.". J Virol 61 (4): 1125-35. PMC 254073. PMID 3029407. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC254073/.
- ↑ URL: http://www.cms.gov/clia/. Accessed on: 1 April 2012.
- ↑ URL: http://home.ccr.cancer.gov/lop/intranet/policymanual/generalpolicy/CAPCLIA.asp. Accessed on: 1 April 2012.
- ↑ URL: http://cap-acp.org/guide_retention-human-biologic-material.cfm. Accessed on: 6 May 2012.
- ↑ Ullman, David G. (1997). The mechanical design process. Toronto: McGraw-Hill Companies Inc.. ISBN 0-07-065756-4.
- ↑ URL: http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=42641. Accessed on: 18 April 2012
- ↑ URL: http://www.cms.hhs.gov/Regulations-and-Guidance/Legislation/CLIA/index.html?redirect=/clia/. Accessed on: 18 April 2012.
- ↑ URL: http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=laboratory_accreditation%2Faboutlap.html&_state=maximized&_pageLabel=cntvwr. Accessed on: 18 April 2012.
- ↑ URL: http://www.keele.ac.uk/pharmacy/general/npbs/. Accessed on: 18 April 2012.
External links
- UK national benchmarking (keele.ac.uk).
- Multirule quality control - (westgard.com) - statistical process control explained for the mathematically challenged.