quality control in clinical pathology

QUALITY CONTROL IN PATHOLOGY

QUALITY CONTROL

IN

PATHOLOGY

Quality Assurance in Healthcare

• All management systems are now focused on getting the job done.

• All promise more efficient and effective management

• Some have been effective in making larger profits while others have been effective in providing a better service to the client

DEFENITION

Quality Control - QC refers to study of those errors which are the responsibility of the laboratory and the procedures used to recognize and minimize them.

This study include all errors arising with in the laboratory b/w receipt of specimen and dispatch of the report.

Quality assurance:

It is the sum total of all lab activities that are undertaken to ensure generation of accurate and reliable results.

The Quality Assurance Cycle

•Data and Lab Management•Safety•Customer Service

Patient/Client PrepSample Collection

Sample Receipt and Accessioning

Sample TransportQuality Control

Record Keeping

ReportingPersonnel CompetencyTest Evaluations

Testing

Purchasing & Inventory

AssessmentOccurrence Manageme

nt

Information Management

Process Improvemen

t

Customer Service

Facilities & Safety

The Quality System

Organization

Personnel Equipment

Documents & Records

Process Control (QC & EQA) & Specimen

Management

Quality systems

ObjectivesTo prevent risksTo detect deviationsTo correct errorsTo improve efficiencyTo reduce costs

How : By establishing a quality manual defining

Organizational structure – StaffResponsibilities Procedures and processesResourcesDocumentation

Factors influencing quality:

Pre analytical Analytical Post analytical

Right Specimen Laboratory professionals

Recording

Right collection Reagents Interpretation

Right labeling Equipment Turnaround time

Right quantity Selection of test - SOP

Report to right user

Right transport Records

Right storage Bio-Safety

Areas of Phlebotomy subject to QC

• Patient preparation procedures• Specimen collection procedures

IdentificationEquipmentPuncture deviceEvacuated tubes

• Labeling• Technique• Collection priorities• Delta checks

• Specimen rejection

mislabeled/unlabeled improper transport temp. or container/mediumquantity not sufficient (QNS) leakingdelay in transport (> 2 hrs unpreserved) inappropriately received in fixative, or received

dried up

MUST COMMUNICATE WITH CARE TEAM

User manual

• Example of QA documentation• Chart or type form• Contains information on minimum amount

of specimens required, special handling desired, reference values, TAT etc.

Procedure Manual

• Standardization purposes• Must be updated annually• Written in a special format – NCCLS• States laboratory policy and procedures that

apply to each test in the lab

Information found in a Procedure Manual

• Purpose of the procedure• Specimen type and collection method• Equipment and supplies required• Detailed step-by-step procedure• Limitations and variables of the method• Corrective actions• Method validation• Normal values and references

Internal Quality control: IQCNature: Concurrentperformed by: lab staffObjective: Reliable results on a daily basis

External quality assessment: EQANature: Retrospective to evaluate IQCPerformed by: Independent agencyObjective: Ensure inter laboratory comparability

COMPONENTS OF QUALITY ASSURANCE

IQC

• Based on monitoring the test procedures.• Measurements on specially prepared

materials • Repeated measurements on routine

specimens.• Daily statistical analysis of data obtained• Eliminates differences in random and

systematic errors between samples and standards

EQC

• Evaluation by an outside agency of the performance by numerous laboratories of specially supplied samples.

• National schemes are known as – NEQUAS(National External Quality Assessment Scheme).

STANDARDISATION

• Encompass both materials and methods• Standard material/ reference preparation-• Used to calibrate an analytical instrument.• Reference method – Technique that is used in

association with a reference preparation.• Working method – Intended to use in

routine practice.

National Standard and Regulatory Agencies

• World Health Organization(WHO)• Joint Commission on Accreditation of Healthcare

Organizations (JCAHO)• College of American Pathologists (CAP)• Clinical Laboratory Improvement Amendments of 1988

(CLIA ’88)• National Committee for Clinical Laboratory Standards

(NCCLS)• National Accrediting Agency for Clinical Laboratory

Sciences (NAACLS)

QC

Hematology

Cytology

Clinical pathology

Histopathology

QC IN HEAMATOLOGY

Preanalytical phase

category Variables

Sample collection Patient identification,labelingPhlebotomy techniqueVolume Sample collection tube

Sample HandlingStorage

Agitation, centrifugation

Transportation

Patient Factors Physiological variablesPathological states

Types of control materials• Assayed

mean calculated by the manufacturermust verify in the laboratory

• Unassayedless expensivemust perform data analysis

• “Homemade” or “In-house” pooled sera collected in the laboratory characterizedpreserved in small quantities for daily use

REFERENCE PREPARATION

• Red Blood cells ACD/CPD added blood Red cells stabilized with gluteraldehyde Suitable sized particles• White Blood Cells Fixed & concentrated human blood. Turkey /Chicken red cells

• Hemoglobin standardized haemolysate• Platelet platelets separated by centrifugation (200g for 10') ,fixed by gluteraldehyde.

TEST PROCEDURES

• Measurement of prepared materials.• Repeated measurement/Replicate testing.• Duplicate testing.• Short hand checking• Delta check• Daily statistical analysis.

Analysis of Control Materials

• Need data set of at least 20 points, obtained over a 30 day period

• Calculate mean, standard deviation, coefficient of variation; determine target ranges

• Develop Levy-Jennings charts, plot results

Levy-Jennings Chart A graphical method for displaying control

results and evaluating whether a procedure is in-control or out-of-control

Control values are plotted versus time Gaussian distribution curve Cusum chart

ANALYSIS OF EQA DATA

• Deviation index• Target value & bias• Youden XY plot - same analysis on two diff.

control and plot on X & Y axis

QUALITY CONTROL IN HISTOPATOHLOGY

Quality assurance in HISTOPATHOLOGY

Concept of QC in histopathology lab is relatively young

It may be due to,descriptive nature of report lack of objective numerical data Individual judgment and bias No uniformity of reporting pattern

QUALITY ASSURANCE

This make assessment and implementation of QC is more difficult in histopathology

Even though we can implement QC in histopathology

it may be Analytical Post analytical

Pre analytical

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

According to CAP, 1. Preanalytical part - all process for

generation of good section 2.Analytical part - interpretation of slide

and accurate diagnosis 3.Post analytical part - proper dispatching

of result, storage

Pre analytical

All process up to submission of slide majority errors occur in this stage Sample accession and identification errors

Avoided by barcode technology Maintain a good referral form with all

possible details and that should make available in sample collection area

Good fixation is very necessary for good result

Fixation problems are, Should be fixed immediately Volume of fixative Conc. & type of fixative Adequate time of fixation Space in the container It should be cut open for proper internal after grossing Leakage of fixative

Decalcification problem Should remove any traces of calcium salt from

the tissue Always maintain

proper time good decalcifying fluid check end point of decalcification

Tissue processing and embedding

Always maintain good quality reagent Periodical changing of processing fluid Maintain a appropriate treatment time If tissue processor used, Ensure complete working Use closed type processor Temp. of paraffin wax Use Tissue Teck system for embedding

Section cutting

Use good quality microtome Sharp knifeProper adjustment of anglePeriodic calibration of micrometerCryostat proper handling of sample correct temperature anti-roll plate position

Staining

Control is used parallel with each batch of staining

Maintain good quality of regentStandard operating procedure Filter stain regularlySpecial stains are done with suitable controls If automatic stainer used, check their working

Mounting and labeling

Use appropriate good mounting media dilute DPX if it become very thick with

xyleneLabel should be affixed with serial numberWriting should be legibleLabel ideally carry name of laboratoryPrefer to bar code labeling system

Analytical errors

Assessment of analytical errors are not an easy taskMaintained by, Intradepartmental consultation ; review selected cases

by colleague Comparison with other reports (cytology, frozen) RBRC © by same person – for precision © diff. person – for accuracy Slide transferring and examination between two

institution

Post analytical QC

Involves, Report generation without any transcription

error Double checking of printed report Counter signed by consultant pathologist Report dispatch to right person Storage of reported material Disposal of specimen Monitor TAT

EQC in histopathology *CAP and UK- NQAS – international programmer In India,

Indian College Of Pathology with collaboration

with Association of Pathologist in North America(AIPNA) run EQC as a part of NABL accreditation

Inter-Laboratory Quality Assessment Programe

for Histopathology (ILQA-HP) under ILQA- Bangalore

EQA programme involves

Scheme divided in to two categories asses pre analytical aspect asses analytical aspect

Pre analytical assessment

Done by sending a bit of formalin fixed tissue measuring made from a common source to each of participating lab

They process ,cut and stain the tissue in their set up

Stained section are send back for assessment

Analyses as, Stained section are examined by 5 experts & Score as ,

score 1 - unsatisfactory score 3 - average score 2 - poor score 4 - good score 5 - excellent Give mark as processing - 5 mark sectioning - 5 mark staining - 5 mark total 15 mark

lab that mark below 3 will take immediate action

Analytical aspects,

Section obtained in one common source is stained with H&E and distribute to lab along with all details

pathologist examine and report was returned

to nodal centre for assessment

QUALITY CONTROL IN CYTOLOGY

Cytopathology QC

Will Require:Observation of technical

proceduresReview of QI program and

indicatorsOn-site microscopic review standardization in reporting

format

Cytopathology QC

• General Elements of QI

Technical and procedural (QC)Professional/diagnostic activities of

cytotechnologists and pathologists (QI)Quality of the diagnostic report (QC/QI)

Specimen Collection and Receipt

• Specimens properly identified• Instructions available for preferred specimen

collection/preparation• Requisition: complete data requested

including date, source, physician, LMP, pertinent clinical information, etc.

• Criteria for specimen rejection and notification of unacceptable specimens

Cytology Stains

Stains labeled and dated Cytology stains: new requirement for annual

inventory to ensure proper storage and quality (many stains do not expire)

Papanicolaou stains filtered or replaced regularly

Papanicolaou stain prepared with good reagent Regular monitoring of stain characteristics

Instrumentation

• Evidence of active review of results of instrument maintenance and function (II)

• Automated instruments (Phase II)– Documentation of adherence to manufacturer-

recommended protocol for implementation– Documentation of appropriate technical and

interpretive training– Written procedure to verify diagnostic & adequacy

performance of screening instrument

Instrumentation

• Automated screening systems If tolerance limits exceeded, is there

documentation of corrective action?Documented procedure for handling workload

during instrument failureDocumented procedure for handling slides not

successfully processed“Negative” slides subject to 5 year retro review

On-Site Microscopic Review• Not meant to be comprehensive rescreen or

competency review, but a means of facilitating evaluation of overall procedures

• 10 -15 case review recommended including: > Unsatisfactory

> Reactive > Positive for all abnormality reported

“Must have written criteria”

On-Site Microscopic Review

• Evaluate adequacy, technical quality, labels• Determine if significant cells identified• Compare with written interpretive report• Check requisition for complete information• Discrepancies analogous to PAP program• Team leader should discuss significant

discrepancies with laboratory director• Record specimen category & discrepancies

Cytopathology Reports

• Name/unique identifier/accession number• Birth date / age• Physician / clinic• Anatomic source / type of specimen• Collection, receipt, and reporting dates• Description of specimen on receipt• Interpretation (descriptive terminology)• Space for comments / recommendations

Retention Guidelines

ALL slides 5 yearsFNA slides 10 yearsReports 10 yearsAccession logs / worksheets 2 yearsMaintenance records 2 yearsQC / QA records 2 years

Service / repair records instrument life

Slide Storage

• Stored in accessible manner• Documented policy for protecting and

preserving the integrity of original slides• Policy to ensure defined handling and

documentation of referral, transfer, receipt of original slides for availability

• Documentation when material is loaned to programs such as PAP (including receipt)

Cytopathology Quality Improvement

• Correlation with clinical findings• Reconciliation of Disparities• Documentation of consultations• Documentation of technical quality• Participation in PAP program or CLA-approved

alternative program

Pap Rescreening

• Laboratory must rescreen a minimum of 10% of each cytotechnologist’s initially judged as negativePerformed by individual qualified to be supervisor (3 years experience)Must include both high risk and randomly selected

casesCases not reported until rescreening completePathologists exempt (but rescreening advised)

EQA IN CYTOLOGY

1. Exchange of slide programme A set of gynecological and

nongynecological smears are distributed to diff. lab

rechecking or reassessment of slide2.Laboratory accreditation and certification Indian Academy of cytologist

Accreditation of IAC is based on,

Workload Staff pattern Report generation and methodology Screening of specimen Diagnostic verification Follow-up Filing of report and slide Continuing education

QUALITY CONTROL IN CLINICAL PATHOLOGY

QA in CLIP

> Still in dormant state > Require great attention > International and national agency

should come forward

QC in urine analysisSpecimen Collection

First morning voiding (most concentrated) Record collection time Type of specimen (e.g. “clean catch”) Analyzed within 2 hours of collection Free of debris or vaginal secretions

analysis

Performed person should be well trainedMaintain good quality reagents for chemical

examination with suitable controlMicroscopy recheck if neededMaintain an uniformity in reporting

Microscopic UA

Correlate with cloudiness and other findingsQuality control

– Consistent volume– Centrifugation– Well mixed fresh specimen– Microscopy (wet mount, use low light)

Accreditation Bodies

• College of Pathologists (CAP) , USA• Joint Commission on Accreditation of Hospitals

(JCAHO), USA• Clinical Pathology Accreditation (CPA), UK Ltd• National Association of Testing Authorities

(NATA), Australia• Department of Standards (DSM) Malaysia –

THANK YOU