External Quality Assessment Schemes

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External Quality Assessment Schemes

• Amadeo Sáez-Alquézar

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Procedures for Quality Control of Infectious
Disease Screening

• QUALITY ASSURANCE
• QUALITY CONTROL (INTERNAL)
• QUALITY ASSESSMENT
• EXTERNAL QUALITY CONTROL
• A PROCEDURE TO VERIFY THE QUALITY OF RESULTS
  GENERATED BY A LABORATORY
• CORRESPONDS TO AN EXTERNAL EVALUATION OF THE
  LABORATORYS PERFORMANCE
• EXTERNAL QUALITY CONTROL PROGRAMS (EQCPs)

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External Quality Assessment

• External Quality Assessment (EQA)
• or External Quality Control Programs
• (EQCPs) should be considered a challenge to
  check the efficacy of the Quality Assurance and
  the Internal Quality Control, in each laboratory.
• Multipanels a necessary tool.

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MULTIPANEL

• In the specific case of the serological trial of
  blood bank, the main interest is to evaluate the
  performance of the laboratory responsible for the
  screening tests
• For this purpose, there is a panel with positive
  samples for all tests normally applied in the
  screening and some negative ones
• This sort of serum panel is called MULTIPANEL

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Multipanel for EQCPsBlind Panel

• 12 or 24 serum samples
• Positive samples of
• HIV
• HTLV
• HBV , Anti-HBc
• T. cruzi
• Syphilis
• HCV
• Negative samples

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PANELS OF SERA
PRODUCTION CaCl2 or CaCl2 thrombine Centrifug.
Filtrat. Preservative
Plasma Units
Serum Units
Testing
Samples Selection According To The
Purpose MULTIPANELS SPECIFIC PANELS BORDERLINE
PANELS
Storage
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EXTERNAL QUALITY ASSESSMENT PROGRAMS (ECQPs)

• ORGANIZING CENTER (OC)
• Coordination and development
• PARTICIPATING LABORATORIES (PLs)

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Organizing Laboratory
Participanting Laboratories
Shipment
Samples Processing
Multipanels Manufacturing
Results
Disclosure of the correct results
Acknowledging the correct results
Final Report Evaluation
Analysis of the results
Self Evaluation
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Organizing Center (OC) Responsibilities

• Produces Multipanels (Testing).
• Organizes and manages the Programs.
• Maintains and up dating files of the PLs.
• Ships Multipanels, keys, final reports and
  evaluations.
• Analyses data and produces a final report.

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Participating Laboratories (PLs) Responsibilities

• Adhesion to the programs.
• Processing of the Multipanels.
• Delivery of the results to the OC
• Observation of the deadline to send back the
  results for the OC.
• Self evaluation.
• Reception and analysis of the final report.

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General Comments - 1

• The Programs intend to assess the performance of
  the PLs. Are developed with the intent of
  advising and cooperating ensuring confidential
  individual results.
• Possible failures in the internal procedures of
  the PLs may give rise to False Positive Results
  and / or False Negative Results in processing the
  Multipanels.

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General Comments - 2

• The revision of internal procedures and analysis
  of products and equipment utilized will clarify
  the causes of the problems observed.

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General Comments - 3

• We emphasize that FPR and FNR observed should
  not be attributed exclusively to the origin and
  characteristics of the kits utilized by each PL.
  Results must serve as a warning of the need for a
  revision of all the items related to use of
  equipment in general including technical staff
  involved and internal controls utilized.

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Whats the cost of an EQAP?

• Calculate
• The number of PLs of Multipanels.
• Multipanels price.
• Location of the PLs.
• Shipment costs (customs taxes)
• Documents and software
• Staff involved

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EQCPs - Final Report Contents

• Number, type and geographic distribution of the
  Participant Laboratories
• Charaterization of the Multipanel
• Strategies (type of methodologies) used by each
  Participant Laboratory
• Confirmatory tests used

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EQCPs - Final Report Contents

• False Positive and False Negative Results
• Number, and distribution by methodology, by
  disease and by trademark of the used kits
• Summary of the discrepancies observed during the
  development of the program
• Relevant information

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Evaluation of the LaboratoriesCriteria

• A Correct Results
• Without FPR or FNR
• B1 False Positive Results
• lt 5 of the total assays
• B2 False Positive Results
• gt 5 of the total assays
• C False Negative Results

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Development of External Quality Control Programs
in Serology
BRASIL 1993 1994 MINISTRY OF HEALTH /
FPS PUBLIC BLOOD BANKS 1st 32 Labs 2nd
58 Labs 3rd 60 Labs 4th 61 Labs
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Development of External Quality Control Programs
in Serology
BRASIL 1995 2002 PANEL / SBHH PUBLIC AND
PRIVATE BLOOD BANKS 22 PROGRAMS 125 LABS
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Development of External Quality Control Programs
in Serology
1997 / 2000
1995 / 96
1996
Latin America 5 Programs 16 countries (21 PLs)
One Program
Central America and Colombia (3 Programs)
PAHO /WHO/ FPS
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Development of External Quality Control Programs
in Serology - 2002
CARIBBEAN 21 Countries 24 Labs
LATIN AMERICA 15 Countries 20 Labs
BRASIL 125 Labs
PAHO/PANEL
CAREC/PAHO/PANEL
PANEL
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Main Problems Detected During the Development of
the EQCPs

• As a consequence of
• Contamination (FPR).
• Transcription of the results (FNR and FPR).
• Features and limitations of the used
  methodologies (FNR and FPR).
• The equipment (manual and automatic).
• Inadequate IQC procedures.

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False Negative and False Positive Results ()
Observed During The Development of Five EQCPs in
Latin America (1997-2000)
PAHO / WHO / FPS
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False Negative and False Positive Results ()
Observed During The Development of Eight EQCPs in
Brasil (Aug1999-dec2001)
PANEL / SBHH
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False Negative and False Positive Results ()
Observed During The Development of Eight EQCPs in
Brasil (Aug1999-dec2001)
Anti-T.cruzi screening tests
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False Negative Results (), by Methodology,
During The Development of Eight EQCPs in Brasil
(Aug1999-dec2001)
Anti-T.cruzi screening tests
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Tests used by Brazilian Blood Banks in the
Serological screening for T.cruzi (2001)
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EQCPs in the Caribbean RegionParticipating
Countries

• Anguilla
• Antigua
• Aruba
• Bahamas
• Barbados
• Belize
• Bermuda
• British Virgin Islands
• Cayman Islands
• Curaçao
• Dominica
• Granada

• Guyana
• Jamaica
• Montserrat
• St. Kitts
• Nevis
• Saint Lucia
• St. Vicent Grenad
• Suriname
• Trinidad Tobago
• Trinidad
• Turks Caicos Islands

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Countries Participating in Latin America
PAHO/PANEL External Quality Control Programs

• Argentina (3)
• Bolivia (2)
• Chile
• Colombia
• Ecuador
• El Salvador (2)
• Guatemala
• Honduras

• Nicaragua
• Panamá
• Paraguay (2)
• Perú
• Rep. Dominicana
• Uruguay
• Venezuela

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The support from PAHO/WHO for the development
of the Programs for External Quality Control in
Serology in Latin America has greatly
contributed to the improvement of the quality
of Blood used in all countries in this region.
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At the same time, the organizing of workshops
and training programs has generated a multiply
effect, allowing each country to produce their
own sera panels and internally develop their
own Quality Control Programs.
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Multiply Effect Generated by the Development of
the EQCPs in Latin America

• 1993
• 4 countries (limited controls)
• 2001
• 15 countries (21 laboratories) participating of
  PAHO/EQCPs
• 10 countries performing EQCPs Nationally (after
  instruction)

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It is very important that these actions from
PAHO/WHO continue, and also be intensified,
so that the countries of Latin America and the
Caribbean region can achieve the same quality
level of Blood and Blood Components as the rest
of the Americas.  
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I would like to express my thanks to PAHO/WHO,
in particular to Dr. Gabriel Schmunis and Dr.
José Ramiro Cruz, for the support and confidence
given to me, which permitted me to develop the
activities as the Latin American External
Quality Control Programs Coordinator in Serology
and Director of the Collaborating PAHO/WHO center
in Brazil. I would also to express my thanks to
Dr. Dalton Chamone and Dr. Marcia Otani, for the
support given to me during the period from 1990
to 1998, when I was Working at FPS.