Quality Control inQuality Control inHistopathologyHistopathology

Bello J.M.Bello J.M.

OutlineOutline

IntroductionIntroductionWhat is Quality Control?What is Quality Control?Related TerminologiesRelated TerminologiesQC as it relates to HistopathologyQC as it relates to Histopathology

Variables that affect the quality of resultsVariables that affect the quality of results How to achieve Quality Control How to achieve Quality Control General recommendationsGeneral recommendations

ConclusionConclusion

INTRODUCTIONINTRODUCTION

Maintaining a high standard of care in Maintaining a high standard of care in medicine is important both to the public medicine is important both to the public and to the medical profession.and to the medical profession.

The processes by which these standards The processes by which these standards are monitored and maintained have been are monitored and maintained have been given different labels depending on their given different labels depending on their geographical and political contexts.geographical and political contexts.

Such terms include Medical Audit, Clinical Such terms include Medical Audit, Clinical Audit and Quality ControlAudit and Quality Control

Introduction ctdIntroduction ctd

The following comments are heard far too often in The following comments are heard far too often in laboratory medicine: laboratory medicine: ‘‘‘‘This result can’t be right!” This result can’t be right!” ““The laboratory messed up again!’’ The laboratory messed up again!’’

Clinicians often attribute many patient results that Clinicians often attribute many patient results that do not fit expected findings to laboratory error.do not fit expected findings to laboratory error.

The National Academics Institute of Medicine (IOM) The National Academics Institute of Medicine (IOM) in the U.S.A. estimates that approximately 44,000 in the U.S.A. estimates that approximately 44,000 to 98,000 deaths occur annually in that country to 98,000 deaths occur annually in that country alone due to medical errors.alone due to medical errors.

Introduction ctdIntroduction ctdSome of these errors occur in the Some of these errors occur in the

laboratory histopathology inclusive.laboratory histopathology inclusive.Error in clinical laboratories is any defect Error in clinical laboratories is any defect

from ordering tests to reporting results and from ordering tests to reporting results and appropriately interpreting and reacting on appropriately interpreting and reacting on these.these.

What is QCWhat is QC Quality ControlQuality Control - QC refers to the measures - QC refers to the measures

that must be included during each assay run that must be included during each assay run (tissue processing) to verify that the test is (tissue processing) to verify that the test is working properly.working properly.

It is a process or system for monitoring the It is a process or system for monitoring the quality of laboratory testing, and the accuracy quality of laboratory testing, and the accuracy and precision of resultsand precision of results

It involves routine collection and analysis of data It involves routine collection and analysis of data from every test run or procedurefrom every test run or procedure

Thus, QC allows detection of errors for Thus, QC allows detection of errors for immediate corrective actionimmediate corrective action

Quality Assurance (QA)Quality Assurance (QA)

Quality AssuranceQuality Assurance - QA is defined as the - QA is defined as the overall program that ensures that the final overall program that ensures that the final results reported by the laboratory are correct.results reported by the laboratory are correct.

The aim of quality control is simply to ensure The aim of quality control is simply to ensure that the results generated by the test are correct. that the results generated by the test are correct. However, quality assurance is concerned with However, quality assurance is concerned with much more: that the right test is carried out on much more: that the right test is carried out on the right specimen, and that the right result and the right specimen, and that the right result and right interpretation is delivered to the right right interpretation is delivered to the right person at the right timeperson at the right time

Quality Assurance vs. Quality Quality Assurance vs. Quality ControlControl

Quality ControlQuality Control

A series of analytical measurements used to assess the quality of the analytical data

(The “tools”)

Quality AssuranceQuality Assurance

An overall management plan to guarantee the integrity of data

(The “system”)

Quality control, Quality AssuranceQuality control, Quality Assuranceand Total Quality Managementand Total Quality Management

Thus the terms QC, and Quality Assurance (QA) Thus the terms QC, and Quality Assurance (QA) differ from each other in the degree of process differ from each other in the degree of process and organizational involvement, which is overall and organizational involvement, which is overall and maximal in TQM.and maximal in TQM.

For all practical purposes, all these elements For all practical purposes, all these elements should be focused to should be focused to a) generate an accurate histopathology report a) generate an accurate histopathology report

andand b) enable easy retrieval and review if needed b) enable easy retrieval and review if needed

over a defined time period. over a defined time period.

QC IN HISTOPATHOLOGYQC IN HISTOPATHOLOGY

The concept of quality control, which is deeply The concept of quality control, which is deeply rooted in most other disciplines of laboratory rooted in most other disciplines of laboratory medicine, is relatively young in the histopathology medicine, is relatively young in the histopathology department.department.

Assessment and implementation of quality control Assessment and implementation of quality control is more difficult in histopathology due to the is more difficult in histopathology due to the inherent qualities such asinherent qualities such as the lack of objective numerical data,the lack of objective numerical data, descriptive nature of reports, descriptive nature of reports, subjectivity, individual judgment and bias, subjectivity, individual judgment and bias, non uniformity of reporting patterns, etc.non uniformity of reporting patterns, etc.

Variables that affect the quality of Variables that affect the quality of resultsresults

The educational background and training of The educational background and training of the laboratory personnelthe laboratory personnel

The condition of the specimensThe condition of the specimensThe controls used in the test runsThe controls used in the test runsReagentsReagentsEquipmentEquipmentThe interpretation of the resultsThe interpretation of the resultsThe transcription of resultsThe transcription of resultsThe reporting of resultsThe reporting of results

Variables that affect the quality of Variables that affect the quality of resultsresults

These variables can be grouped into three These variables can be grouped into three phases of operation which Quality control is phases of operation which Quality control is traditionally applicable to. These are:traditionally applicable to. These are:

1) the pre-analytical phase, 1) the pre-analytical phase, 2) the analytical phase and 2) the analytical phase and 3) the post-analytical phase 3) the post-analytical phase

The pre-analytical phase is related to sample collection, The pre-analytical phase is related to sample collection, transport, accession and processing.transport, accession and processing.

The analytical phase is related to actually carrying out the The analytical phase is related to actually carrying out the test (manual/automated) test (manual/automated)

The activities that follow (transmission of results, The activities that follow (transmission of results, storage/disposal of samples, maintenance of test data, etc.) storage/disposal of samples, maintenance of test data, etc.) comprise the post-analytical part. comprise the post-analytical part.

In the departments such as clinical biochemistry, hematology In the departments such as clinical biochemistry, hematology and immunoassay where numerical data is obtained, and immunoassay where numerical data is obtained, methods for analysis of quality are well established. methods for analysis of quality are well established.

When descriptive reports are made, such an assessment When descriptive reports are made, such an assessment becomes less simple though not unachievable becomes less simple though not unachievable

A good quality histological section is the starting A good quality histological section is the starting point of an accurate histopathology report.point of an accurate histopathology report.

All the processes involved in generating the All the processes involved in generating the section may be grouped under the pre-analytical section may be grouped under the pre-analytical part. part.

The analytical part concerns the interpretation of The analytical part concerns the interpretation of the slide and making an accurate diagnosis. the slide and making an accurate diagnosis.

The post-analytical part involves the generation The post-analytical part involves the generation and transmission of the histopathology report, and transmission of the histopathology report, storage/disposal of samples, slides and blocks storage/disposal of samples, slides and blocks and proper retention of test results.and proper retention of test results.

Pre-analytical aspectsPre-analytical aspects

All processes involved up to the All processes involved up to the submission of stained slides for analysis submission of stained slides for analysis are grouped under pre-analytical. are grouped under pre-analytical.

Newer models for the pre-analytical phase Newer models for the pre-analytical phase also include aspects like patient also include aspects like patient satisfaction with the collection process, satisfaction with the collection process, professional staff satisfaction with professional staff satisfaction with arrangements made by the laboratory arrangements made by the laboratory towards sample collection and transport towards sample collection and transport

Preanalytical ctdPreanalytical ctd Majority of errors in the laboratory (histo lab Majority of errors in the laboratory (histo lab

inclusive) relate to the pre-analytical phase.inclusive) relate to the pre-analytical phase. A lot has been said and written about the A lot has been said and written about the

importance of primary fixation and the choice of importance of primary fixation and the choice of fixatives for specific histopathology investigations. fixatives for specific histopathology investigations.

It is the responsibility of the lab to ensure that It is the responsibility of the lab to ensure that documented instructions containing relevant documented instructions containing relevant information are made available at all points of information are made available at all points of specimen collection. specimen collection.

Correct patient identification by a unique Correct patient identification by a unique accession number that is traceable to the accession number that is traceable to the specimen and report all through the process is of specimen and report all through the process is of prime importanceprime importance

Similarly, wrong identification of anatomic location as well as Similarly, wrong identification of anatomic location as well as laterality of biopsy (right/left) are common errors that should be laterality of biopsy (right/left) are common errors that should be avoided. avoided.

It would be worth while for the laboratory to design its own "referral It would be worth while for the laboratory to design its own "referral form" for histopathology and make it available to all areas of sample form" for histopathology and make it available to all areas of sample collection. collection.

This form should provide space for entry of the relevant clinical This form should provide space for entry of the relevant clinical data. data. It may be useful to insert check boxes for better clinician It may be useful to insert check boxes for better clinician

compliance. compliance. Dialogue with the clinician about the importance of properly filled Dialogue with the clinician about the importance of properly filled

forms may be needed and whenever clinical data is not provided, forms may be needed and whenever clinical data is not provided, the laboratory should take the initiative to extract relevant data the laboratory should take the initiative to extract relevant data either from the treating physician or hospital files. either from the treating physician or hospital files.

Other areas of error in the pre-analytical Other areas of error in the pre-analytical phase include lost specimens, inadequate phase include lost specimens, inadequate volume, size, gross description, gross volume, size, gross description, gross sampling, erroneous measurements, sampling, erroneous measurements, extraneous tissue (floaters), improper extraneous tissue (floaters), improper sections/inadequate serials, poor staining sections/inadequate serials, poor staining and mounting quality, etc.and mounting quality, etc.

Steps on how to achieve proper Steps on how to achieve proper control of the pre-analytical processcontrol of the pre-analytical process1.1. Standard procedures for sample accession, Standard procedures for sample accession,

identification, acceptance/rejection, gross examination identification, acceptance/rejection, gross examination and sampling and all the steps that follow must be and sampling and all the steps that follow must be documented.documented.

This SOP should be written in simple language that can be understood This SOP should be written in simple language that can be understood by all and should be available at the workplace and all technical staff by all and should be available at the workplace and all technical staff should be aware of its contents.should be aware of its contents.

2.2. Planned changing of chemicals used for processing Planned changing of chemicals used for processing based on the number of tissues passed through. This based on the number of tissues passed through. This schedule will prevent under processing and unnecessary schedule will prevent under processing and unnecessary rework and loss of tissue. rework and loss of tissue.

The same also applies to the deparaffinization, staining, dehydration The same also applies to the deparaffinization, staining, dehydration and clearing steps for sections.and clearing steps for sections.

Steps on how to achieve proper Steps on how to achieve proper control of the pre-analytical processcontrol of the pre-analytical process3.3. Usage of controls for routine and special stains Usage of controls for routine and special stains

daily as a routine is strongly recomended. daily as a routine is strongly recomended. For routine H & E staining, the laboratory may identify one tissue For routine H & E staining, the laboratory may identify one tissue block with a good mixture of hematoxyphilic and eosinophilic tissue block with a good mixture of hematoxyphilic and eosinophilic tissue (cervix, fibroadenoma, etc.) as a control. (cervix, fibroadenoma, etc.) as a control.

44. The microtome should be of good quality and . The microtome should be of good quality and serviced regularly.serviced regularly.

Periodic calibration of the micrometer should be made to ensure Periodic calibration of the micrometer should be made to ensure consistency of section thickness.consistency of section thickness.

55.. Care should be taken not to induce tissue Care should be taken not to induce tissue artifacts due to improper processing, artifacts due to improper processing, sectioning, staining and mounting.sectioning, staining and mounting.

66.. The label affixed on the stained slide should be The label affixed on the stained slide should be of an appropriate size so that it does not of an appropriate size so that it does not project beyond the slide or cover the tissue project beyond the slide or cover the tissue sections. sections.

1.1. The identification should be legible and should The identification should be legible and should ideally carry the name of the laboratory. ideally carry the name of the laboratory.

2.2. Using bar code labels, one can incorporate Using bar code labels, one can incorporate demographic data such as the name of the demographic data such as the name of the laboratory, the name of the patient, the laboratory laboratory, the name of the patient, the laboratory ID number and the date. ID number and the date.

Post-analytical aspectsPost-analytical aspects

The traditional laboratory approach to the post-The traditional laboratory approach to the post-analytical phase involves analytical phase involves report generation without transcription errors, report generation without transcription errors, report transmission/dispatch to the right person(s), report transmission/dispatch to the right person(s), storage of reported material as well as reported data storage of reported material as well as reported data

and and safe disposal of specimens thereafter. safe disposal of specimens thereafter.

Newer models include billing issues, patient Newer models include billing issues, patient safety issues (reporting of critical results), turn safety issues (reporting of critical results), turn around time (TAT) and general customer around time (TAT) and general customer satisfaction (wait times), etc. satisfaction (wait times), etc.

Monitoring of TAT is of vital importance and Monitoring of TAT is of vital importance and laboratories should strive to achieve the goal of laboratories should strive to achieve the goal of signing out the majority of cases within 48 hours signing out the majority of cases within 48 hours of receipt of the specimen. of receipt of the specimen.

The use of microwaves may assist in improving The use of microwaves may assist in improving the TAT especially for small biopsies. the TAT especially for small biopsies.

The TAT of frozen sections should also be The TAT of frozen sections should also be monitored and potential bottle-necks should be monitored and potential bottle-necks should be eliminated. eliminated.

The retention period for specimens has always The retention period for specimens has always been a subject of debate and national guidelines been a subject of debate and national guidelines for this are warranted. for this are warranted.

Analytical aspectsAnalytical aspects

Unlike in other disciplines of laboratory Unlike in other disciplines of laboratory medicine, assessment of analytical aspects in medicine, assessment of analytical aspects in histopathology is not easy given the subjectivity histopathology is not easy given the subjectivity of the reports. of the reports.

Error detection and avoidance in histopathology Error detection and avoidance in histopathology has been written about very often.has been written about very often.

Various modes of internal audits have been Various modes of internal audits have been described and recommended, each with their described and recommended, each with their advantages. advantages.

Recommendations Recommendations for analytical phasefor analytical phase

Intra-departmental consultation (review of selected Intra-departmental consultation (review of selected cases by colleagues) cases by colleagues)

Comparison with other reports Comparison with other reports (frozen/cytology/histopathology) (frozen/cytology/histopathology)

Random case review (blinded re-reporting of random Random case review (blinded re-reporting of random cases) cases) By the same person (check for precision) By the same person (check for precision) By a different person (check for accuracy)By a different person (check for accuracy)

Hierarchical form of reporting Hierarchical form of reporting Using clinicopathological meetings to ensure diagnostic Using clinicopathological meetings to ensure diagnostic

accuracy and maintain good clinical liaison; audit accuracy and maintain good clinical liaison; audit diagnostic changes at these meetingsdiagnostic changes at these meetings

Audit workload levels to ensure an even Audit workload levels to ensure an even distribution of the departmental caseload where distribution of the departmental caseload where possiblepossible

Utilize recommended reporting guidelines and Utilize recommended reporting guidelines and templates, wherever available, with audit of templates, wherever available, with audit of compliancecompliance

External consultations (may need to be done External consultations (may need to be done more often)more often)

Review by expertsReview by experts Participation in continued medical education Participation in continued medical education

(CME) programs (CME) programs

CONCLUSIONCONCLUSION

Error reduction and improved quality are Error reduction and improved quality are essentially two names for the same goal; you essentially two names for the same goal; you can’t have one without the other. can’t have one without the other.

Probably the most important factor for error Probably the most important factor for error reduction is a commitment by the team reduction is a commitment by the team (pathologists, scientists technologists, etc.) to (pathologists, scientists technologists, etc.) to reduce errors/improve quality. reduce errors/improve quality.

THANK YOUTHANK YOU

REFRENCES REFRENCES