EVOLVING ASPECTS OF QUALITY ASSURANCE IN LABORATORY TESTING
Patrick St.Louis, PhD, Dip Clin Chem Sainte-Justine Hospital
Montreal, Canada Congress SCPC, 2004
Slide 2
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
Slide 3
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.
Slide 4
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
Slide 5
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
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.
Slide 8
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
Slide 9
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 )
Slide 10
Studies on laboratory errors pre-analytical errors 30%-75% of
total errors patient/specimen ID errors 34 - 58% of pre-
analalytical 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
Slide 11
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
Slide 12
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
Slide 13
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
Slide 14
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: l protocols
defining critical values and actions l calls and read backs
Problems inherent in manual entry of results Sample storage and
retrieval for supplementary testing; a good system saves time
Slide 15
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
Slide 16
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.
Slide 17
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
Slide 18
Some policies at HSJ patient identification specimen
identification and certification specimens delayed in transport
(use of pneumatic tube system) adequate filling of specimen tubes
(anti- coagulation) instrument maintenance, breakdown and repair
log sheets temperature logs for refrigerators and freezers critical
values protocols: values and actions
Slide 19
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
Slide 20
HSJ 2003/2004: from Certification Forms l 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
Slide 21
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
Slide 22
Publications: NCCLS documents ISO 15189: Standards for Medical
Laboratories Relating to Quality and Competence