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EVOLVING ASPECTS OF QUALITY
ASSURANCE IN LABORATORY
TESTING
Patrick St.Louis, PhD, Dip Clin Chem
Sainte-Justine Hospital
Montreal, Canada
Congress SCPC, 2004
Quality  the total characteristics of a process or
procedure that affect its ability to satisfy its
intended application
To appreciate the need for quality we must
understand the impact of poor quality
automobile: safety/accidents, repairs - time and cost
cigar: taste, low satisfaction, poor reputation - sales
laboratory test result: inappropriate treatment
delays in treatment
direct harm - repeat punctures
social and economic harm
Quality Assurance (QA)  the systematic
activities needed to ensure that the requirements
of quality will be met.
An efective laboratory QA program will provide
reliable test results with a minimum of delay and
the efficient use of resources, taking care to
address patient safety and to minimise laboratory
errors.
 Select processes and identify steps for
improvement
 Need objectives with measurable quality
indicators; objectives should have clinical,
patient care relevance.
 For example: “To reduce the number of
unlabelled specimens received”
 measurable
 patient care relevance:
 number of repeat sticks
 time delay to results and treatment
The laboratory QA program must consider all
phases of the laboratory testing process and
the steps that can benefit from quality
improvement
pre-analytical, analytical and post-analytical
Pre-analytical phase
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patient identification
specimen:collection, identification
laboratory: reception and verification
pre-test handling: separation
decanting
aliquotting (labelling)
Patient identification: (CRITICAL)
 Armbands
“No specimen shall be drawn from a patient
who is not wearing an armband”
 Double identification: name (ask), number
 Special situations: newborns, patients in the ER
 Sample identification: care should be taken to
correctly identify the specimen at this time.
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Specimen
collection: proper procedure; repeat punctures;
correct samples - no omissions; needlestick
injuries
identification: label must be affixed
transport: delays (time-stamping, tube systems)
inappropriate and un-protected samples
Sample volume issues
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Pre-analytical phase
patient identification
specimen:collection, identification
laboratory: reception and verification
data/order entry
pre-test handling: separation
decanting
aliquotting (labelling)
delay or loss in laboratory (this occurs more
often than we would like)
Studies on laboratory errors
 pre-analytical errors  30%-75% of total errors
 patient/specimen ID errors  34 - 58% of preanalalytical errors
Bonini et al. Clin Chem 2002; 48:691-698
Astion et al. Am J Clin Pathol 2003; 120:18-26
CAP-Q Probes study
Order entry errors can be as high as 5% of tests
entered; most frequent  test request not entered
Valenstein & Meier, Arch Pathol Lab Med 1999; 123:1145-1150
Analytical phase
 need well-written protocols (methods; format)
 ensure reliability of test (NCCLS, ISO):
establish or verify linearity
verify limits of detection and analytical range
evaluate precision and accuracy
establish institution-specific reference ranges
 reagent handling: storage, expiry dates; fridge
temperatures
 instrument breakdown and repair logs: down
time causes loss of effective working time and delays
in results
Quality control (QC)  operational techniques
and activities that are used to fulfill
requirements for quality
QC for the analytical phase :
traditional
automatic
electronic
Continuous system monitoring: total system;
remote sensing and monitoring
 use of split samples and other means of
internal assessment and monitoring
 concordance between analysers
 External QC programs (proficiency testing)
External QC results and proficiency testing
material as tests of trueness
Post-analytical phase
 Result validation: automatic, absurd results
(contamination by IV fluids, saline, glucose,)
 Reflex testing eg TSH and T3, T4
 Reports and interpretations (HbS, tumor markers)
 Managing critical and unusual results:
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protocols defining critical values and actions
calls and read backs
 Problems inherent in manual entry of results
 Sample storage and retrieval for supplementary
testing; a good system saves time
 The total QA process can benefit from the
laboratory information system (LIS):
 time stamps
 identity tags
 traceability from specimen collection to
test result
 previous results and delta checks
 format of laboratory reports; reference
values and comments
Approach to QA program
 Develop protocols and policies
 Identify intervention points
 Use Risk Reports: laboratory and/or
hospital; government mandated reporting
 Prepare regular QA reports; ensure
distribution and follow up.
Preparation of QA reports and follow up
 statistical analysis: by period, by clinical
unit
 explain/understand the consequences of
particular problems and the reason for
actions: eg improper sample identification
leading to sample rejection or certification;
real or potential harm to the patient
 avoid blame and seek support
 interdisciplinary problems
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Some policies at HSJ
patient identification
specimen identification and certification
specimens delayed in transport (use of
pneumatic tube system)
adequate filling of specimen tubes (anticoagulation)
instrument maintenance, breakdown and repair
log sheets
temperature logs for refrigerators and freezers
critical values protocols: values and actions
Specimen ID errors: HSJ protocol  rejection
 Specimen not identified/labelled
 no requisition
 identification errors: wrong patient, wrong
label on specimen, wrong requisition, sample
and requisition do not match
Are all mis-labelled samples rejected?
Some samples are hard to replace
 Certification by someone responsible on the
clinical side
HSJ 2003/2004: from “Certification Forms”
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132 sample-related incidents
64 - no identification
36 - wrong identification
number of rejections = 90
number of certifications and acceptances = 8
We have noted a marked decrease in the number
of events; under-reporting of problem cases ?
What about when the test is already done and the
report sent; removing results from the patient
chart; do not transfer results
 Responsibility for QA:
Everyone
An institutional issue, having
administrative support
Uses analytical and statistical tools
 Two aspects
identify and resolve any current problems
long range anticipation to improve processes
Publications: NCCLS documents
ISO 15189: Standards for Medical
Laboratories Relating to Quality and Competence