Accurate Results in the Clinical Laboratory-A Guide to Error Detection and Correction

460 Pages·2019·11.102 MB·English

by  Amitava Dasgupta, Jorge L. Sepulveda

ACCURATE RESULTS
IN THE CLINICAL
LABORATORY
A Guide to Error Detection and Correction
SECOND EDITION
Edited by
A D , P D, DABCC
MITAVA ASGUPTA H
Professor ofPathology andLaboratory Medicine
University ofTexasMcGovern MedicalSchool
Houston,TX, UnitedStates
J L. S , MD, P D
ORGE EPULVEDA H
Professor ofPathology and CellBiology
Columbia University Vagelos College ofPhysicians andSurgeons
NewYork, NY, UnitedStates
List of contributors
AmidAbdullah,MD University ofCalgaryandCalgary SusanJ.Hsiao,MD,PhD DepartmentofPathologyandCell
LaboratoryServices, Calgary,AB,Canada Biology,ColumbiaUniversity IrvingMedicalCenter,
MariaP.Alfaro,PhD Institute forGenomicMedicine, NewYork, NY,UnitedStates
NationwideChildren’sHospital, Columbus,OH, LauraM.Jacobsen,MD DepartmentofPediatrics, Division
UnitedStates ofEndocrinology,University ofFlorida,Collegeof
ChrisAltomare,BS DRUGSCANInc.,Horsham,PA, Medicine,Gainesville, FL,UnitedStates
UnitedStates KamishaL.Johnson-Davis,PhD Department ofPathology,
LelandBaskin,MD UniversityofCalgaryandCalgary UniversityofUtahSchoolofMedicine,ARUPLaboratories,
SaltLakeCity,UT,UnitedStates
LaboratoryServices, Calgary,AB,Canada
LindsayA.L.Bazydlo,PhD DepartmentofPathology, StevenC.Kazmierczak,PhD DepartmentofPathology,
OregonHealth&ScienceUniversity,Portland,OR,
UniversityofVirginia, Charlottesville,VA,UnitedStates
UnitedStates
JessicaM.Boyd,PhD DepartmentofPathologyand
LaboratoryMedicine, CummingSchoolofMedicine, ElaineLyon,PhD Clinical ServicesLaboratory,
HudsonAlphaInstitute forBiotechnology,Huntsville,AL,
UniversityofCalgary,Calgary,AB,Canada;Calgary
UnitedStates
LaboratoryServices,Calgary,AB,Canada
LarryA.Broussard,PhD DepartmentofClinicalLaboratory GwendolynA.McMillin,PhD DepartmentofPathology,
Sciences,LouisianaStateUniversityHealthSciencesCenter, UniversityofUtahSchoolofMedicine,ARUPLaboratories,
SaltLakeCity,UT,UnitedStates
NewOrleans,LA,UnitedStates
VioletaCha´vez,PhD DepartmentofPathology and ChristopherNaugler,MD UniversityofCalgaryand
CalgaryLaboratory Services, Calgary,AB,Canada
LaboratoryMedicine,UniversityofTexasMedicalSchoolat
Houston,Houston,TX,UnitedStates ElenaG.Nedelcu,MD DepartmentofLaboratoryMedicine,
AlexChin,PhD UniversityofCalgaryandCalgary UniversityofCaliforniaSanFrancisco,SanFrancisco,CA,
UnitedStates
LaboratoryServices, Calgary,AB,Canada
AnthonyG.Costantino,PhD DRUGSCANInc.,Horsham, AndyNguyen,MD Department ofPathologyand
LaboratoryMedicine, UniversityofTexasMcGovern
PA,UnitedStates
MedicalSchool,Houston, TX,UnitedStates
AmitavaDasgupta,PhD,DABCC DepartmentofPathology
andLaboratory Medicine,University ofTexasMcGovern OctaviaM.PeckPalmer,PhD DepartmentofPathology,
UniversityofPittsburghSchoolofMedicine, Pittsburgh,
MedicalSchool,Houston,TX, UnitedStates
PA,UnitedStates;DepartmentofCriticalCareMedicine,
PradipDatta,PhD SiemensHealthineers, Newark,DE,
UniversityofPittsburghSchoolofMedicine,Pittsburgh,PA,
UnitedStates
UnitedStates;DepartmentofClinicalandTranslational
RobertA.DeSimone,MD DepartmentofPathologyand Science,UniversityofPittsburghSchool,Pittsburgh,PA,
LaboratoryMedicine, WeillCornell Medicine, UnitedStates
NewYork-PresbyterianHospital, NewYork, NY,
AmyL.Pyle-Eilola,PhD PathologyandLaboratory
UnitedStates
Medicine,NationwideChildren’sHospital,Columbus,OH,
UttamGarg,PhD DepartmentofPathologyandLaboratory UnitedStates
Medicine,Children’sMercyHospitalsandClinics, The
S.M.HosseinSadrzadeh,PhD DepartmentofPathology
UniversityofMissouri SchoolofMedicine, KansasCity,
andLaboratory Medicine, CummingSchoolofMedicine,
MO,UnitedStates
UniversityofCalgary,Calgary,AB,Canada;Calgary
NeilS.Harris,MD DepartmentofPathology,Immunology LaboratoryServices,Calgary,AB,Canada
andLaboratoryMedicine,UniversityofFlorida,Collegeof
JorgeL.Sepulveda,MD,PhD DepartmentofPathologyand
Medicine,Gainesville, FL,UnitedStates
CellBiology,ColumbiaUniversity VagelosCollegeof
JoshuaHayden,PhD DepartmentofPathologyand PhysiciansandSurgeons,NewYork,NY,UnitedStates
LaboratoryMedicine, WeillCornell MedicalCenter,
NewYork, NY,UnitedStates
xi
xii
LISTOFCONTRIBUTORS
BrianRudolphShy,MD,PhD DepartmentofLaboratory GeorgeVlad,PhD DepartmentofPathology&CellBiology,
Medicine,University ofCaliforniaSanFrancisco, ColumbiaUniversityCollegeofPhysiciansandSurgeons,
SanFrancisco,CA,UnitedStates NewYork,NY,UnitedStates
AaronStella,PhD University ofMassachusettsLowell, AmerWahed,MD Department of Pathology and
Lowell,MA,UnitedStates Laboratory Medicine, University of Texas McGovern
YvetteC.Tanhehco,PhD DepartmentofPathologyandCell Medical School, Houston, TX, United States
Biology,ColumbiaUniversity IrvingMedicalCenter, WilliamE.Winter,MD Department ofPediatrics, Division
NewYork-PresbyterianHospital, NewYork,NY, ofEndocrinology,UniversityofFlorida,Collegeof
UnitedStates Medicine, Gainesville,FL, UnitedStates;Departmentof
AshokTholpady,MD DepartmentofPathology and Pathology,ImmunologyandLaboratoryMedicine,
UniversityofFlorida,CollegeofMedicine,Gainesville,FL,
LaboratoryMedicine, UniversityofTexasMDAnderson
CancerCenter,Houston,TX, UnitedStates UnitedStates
ChristinaTrambas,MD,PhD ChemicalPathologist, AlisonWoodworth,PhD Pathology andLaboratory
Medicine, UniversityofKentuckyMedicalCenter,
ChemicalPathologyDepartment, MelbournePathology,
Lexington, KY,UnitedStates
Collingwood,VIC,Australia
Foreword (from the first edition)
Clinicians must make decisions from information showedthatwhenerrorsweremade75%stillproduced
presented to them, both by the patient and ancillary results that fell within the reference interval (when
resources available to the physician. Laboratory data perhaps they should not) [1]. Half of the other errors
generally provide quantitative information, which were associated with results that were so absurd that
may be more helpful to physicians than the subjective they were discounted clinically. Such results clearly
information from a patient’s history or physical ex- should not have been released to a physician by the
amination. Indeed, with the prevalent pressure for laboratory and could largely be avoided by a simple
physicianstoseemorepatientsinalimitedtimeframe, review by human or computer before being verified.
laboratory testing has become a more essential compo- However, the remaining 12.5% of errors produced re-
nent of a patient’s diagnostic work-up, partly as a time- sults that could have impacted patient management.
saving measure but also because it does provide The prevalence of errors may be less now than previ-
information against which prior or subsequent test re- ously, since the quality of analytical testing has
sults, and hence patients’ health, may be compared. improved, but the ramifications of each error are not
Tests should be ordered if they could be expected to likely to be less. The consequences of an error vary
provide additional information beyond that obtained depending on the analyte or analytes affected and
from a physician’s first encounter with a patient and if whether the patient involved is an inpatient or outpa-
the results could be expected to influence a patient’s tient. If the patient is an inpatient a physician, if
care. Typically, clinicians use clinical laboratory testing suspicious about the result, will likely have the oppor-
as an adjunct to their history taking and physical tunity to verify the result by repeating the test or other
examination to help confirm a preliminary diagnosis, tests addressing the same physiological functions,
although some testing may establish a diagnosis, for beforetakingaction. However, if theerroroccurswitha
examplemoleculartestsforinbornerrorsofmetabolism. specimenfromanoutpatientcausinganabnormalresult
Microbiological cultures of body fluids may not only to appear normal, that patient may be lost to follow-up
establish the identity of an infecting organism, but also and present later with advanced disease. Despite the
establish the treatment of the associated medical condi- greatpreponderanceofaccurateresultscliniciansshould
tion. In outpatient practice clinicians primarily order always be wary of any result that does not seem to fit
tests to assist them in their diagnostic practice, whereas withthepatient’sclinicalpicture.Itis,ofcourse,equally
for hospitalized patients, in whom a diagnosis has important for physicians not to dismiss any result that
typically been established, laboratory tests are primarily theydonotlikeasa“laboratoryerror”.Theunexpected
used to monitor a patient’s status and response to result should always prompt an appropriate follow-up.
treatment. Tests of organ function are used to look for The laboratoryhas a responsibility toensure thatphysi-
drug toxicity and the measurement of the circulating cians have confidence in its test results while still
concentrations of drugs with narrow therapeutic win- retainingahealthyskepticismaboutunexpectedresults.
dows is done to ensure that optimal drug dosing is Normal laboratory data may provide some assur-
achieved and maintained. The importance of laboratory ance to worried patients who believe that they might
testing is evident when some physicians rely more on have a medical problem, an issue seemingly more
laboratory data than a patient’s own assessment as to prevalent now with the ready accessibility of medical
how he or she feels, opening them to the criticism of informationavailablethroughcomputersearchengines.
treating the laboratory data rather than the patient. Yet both patients and physicians tend to become over-
In the modern, tightly regulated, clinical laboratory reliant on laboratory information, either not knowing
inadevelopedcountryfewerrorsarelikelytobemade, orignoringtheweaknessoflaboratorytests,ingeneral.
withthemajoritylabeledaslaboratoryerrorsoccurring A culture has arisen of physicians and patients
outside the laboratory itself. One study from 1995 believing that the published upper and lower limits of
xiii
xiv
FOREWORD(FROMTHEFIRSTEDITION)
the reference range (or interval) of a test define should be of pursuit of information rather than just
normality. They do not realize that such a range has data. Laboratory information systems provide the po-
probably been derived from 95% of a group of pre- tential to integrate all laboratory data that can then be
sumed healthy individuals, not necessarily selected integrated with clinical and other diagnostic informa-
with respect to all demographic factors or habits that tion by hospital information systems.
were an appropriate comparative reference for a Laboratory actions to highlight values outside the
particular patient. Even if appropriate, 1 in 20 in- referenceintervalontheircomprehensivereportsoftest
dividualswouldbeexpectedtohaveanabnormalresult results to physicians with codes such as “H” or “L” for
for a single test. In the usual situation in which many high and low values exceeding the reference interval
tests are ordered together the probability of abnormal have tended to obscure the actual numerical result and
resultsinahealthyindividualincreasesinproportionto tocementtheconceptthattheupperandlowerreference
thenumberoftestsordered.Studieshavehypothesized limits define normality and that the presence of one of
that the likelihood of all of 20 tests ordered at the same thesesymbolsnecessitatesfurthertesting.Theuseofthe
timefallingwithintheirrespectivereferenceintervalsis reference limits aspublished decision limitsfor national
only36%.Thestudiesperformedtoderivethereference programs for renal function, lipid or glucose screening
limits are usually conducted under optimized condi- has again placed a greater burden on the values than
tionssuchasthetimesincethevolunteerlastate,hisor theydeserve.Everymeasurementissubjecttoanalytical
her posture during blood collection and, often the time error, such thatrepeateddeterminationswill not always
of day. Such idealized conditions are rarely likely to be yield the same result, even under optimal testing con-
attained in an office or hospital practice. ditions. Would it then be more appropriate to make
Factors affecting the usefulness of laboratory data multiple measurements and use an average to establish
mayariseinanyofthepreanalytical,analyticalorpost- the number to be acted upon by a clinician?
analyticalphaseofthetestingcycle.Failurestoconsider Much of the opportunity to reduce errors (in the
these factors do constitute errors. If these errors occur broadest sense) rests with the physicians who use test
prior to collection of blood or after results have been results. Over-ordering leads to the possibility of more
produced, while still likely to be labeled as laboratory errors. Inappropriate ordering, for example repetitive
errors because they involve laboratory tests, the labo- ordering of tests whose previous results have been
ratory staffs are typically not liable for them. Yet the normal, orordering the wrong test or wrong sequence
staff does have the responsibility to educate those in- ofteststoelucidateaproblemshouldbeminimizedby
dividuals who may have caused them to ensure that careful supervision by attending physicians of their
such errors do not recur. If practicing clinicians were trainees involved in the direct management of their
able to use the knowledge that experienced labo- patients. Laboratorians need to be more involved in
ratorians have about the strengths and weaknesses of teaching medical students so that when they become
tests it is likely that much more clinically useful infor- residents their test ordering practices are not learned
mation could be extracted from existing tests. Outside from senior residents who had learned their habits
the laboratory, physicians rarely are knowledgeable from the previous generation of residents. Blanket
about the intra- and interindividual variation observed application of clinical guidelines or test order-sets has
when serial studies are performed on the same in- probably led to much misuse of clinical laboratory
dividuals. For some tests a significant change for an tests. Many clinicians and laboratorians have attemp-
individual may occur when his/her test values shift ted to reduce inappropriate test ordering, but the
from toward one end of the reference interval toward overall conclusion seems to be that education is
theother.Thusatestvaluedoesnotnecessarilyhaveto themost effectivemeans.Unfortunately,theeducation
exceed the reference limits for it to be abnormal for a needs to be continuously reinforced to have a lasting
given patient. If the preanalytical steps are not stan- effect. The education needs to address the clinical
dardized when repeated testing is done on the same sensitivity of diagnostic tests, the context in which
person, it is more likely that trends in laboratory data they are ordered and their half-lives. Above all edu-
may be missed. Thereis an onus on everyone involved cation needs to address issues of biological variation
intestorderingandtestperformancetostandardizethe and preanalytical factors that may affect test values,
processes to facilitate the maximal extraction of infor- possibly masking trends or making the abnormal
mation from the laboratory data. The combined goal result appear normal and vice versa.
xv
FOREWORD(FROMTHEFIRSTEDITION)
This book provides a comprehensive review of the should be of equal value to clinicians, as to labo-
factors leading to errors in all the areas of clinical lab- ratorians, as they seek the optimal outcome from their
oratory testing. As such it will be of great value to all care of their patients.
laboratorydirectorsandtraineesinlaboratorymedicine
Reference
and the technical staff who perform the tests in daily
practice. By clearly identifying problem areas,the book
[1] GoldschmidtHMJ,LentRW.Grosserrorsandworkflowanalysis
lays out the opportunities for improvement. This book intheclinicallaboratory.KlinBiochemMetab1995;3:131e49.
DonaldS. Young MD, Ph.D
Professor ofPathology andLaboratory Medicine
University ofPennsylvania Perelman College of
Medicine, Philadelphia, PA
Elsevier
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ThisbookandtheindividualcontributionscontainedinitareprotectedundercopyrightbythePublisher(otherthanasmaybenoted
herein).
Notices
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methods,compounds,orexperimentsdescribedherein.Inusingsuchinformationormethodstheyshouldbemindfuloftheirown
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Preface
Clinical laboratory tests have significant impact on of biotin in the troponin assay. Because people take
patient safety and patient management because more megadoses of biotin, this is a serious public health
than70%ofallmedicaldiagnosisarebasedonlaboratory concern.Therefore,weaddedanewchapter(Chapter8).
testresults.Physiciansrelyonhospitallaboratoriesfor Another new chapter (Chapter 16) is also added to
obtaining accurate results and a falsely elevated or discussissuesoffalsenegativeresultsintoxicologydue
falselylowervalueduetointerferenceorpre-analytical to the difficulty in detecting certain drugs such as syn-
errorsmayhavesignificantinfluenceondiagnosisand thetic cathinone (bath salts) and synthetic cannabinoids
management of patients. Usually, a clinician questions (spices). Chapter 27 is also added to discuss sources of
the validity of a test result if the result does not match errors in flow cytometry. Moreover, Chapters 29e31 are
with clinicalevaluation of thepatient and calls labora- alsonewlyaddedchaptersinthesecondedition.
tory professionals for interpretation. However, clini- Theobjectiveofthissecondeditionbookistoprovide
cally significant inaccuracies in laboratory results may acomprehensiveguideforlaboratoryprofessionalsand
go unnoticed and mislead the clinicians into inappro- cliniciansregardingsourcesoferrorsandmisinterpreta-
priate diagnostic and therapeutic approaches, some- tion in the clinical laboratory and how to resolve such
times with very adverse outcomes. The first edition of errors and identify discordant specimens. Accurate lab-
“Accurate Results in the Clinical Laboratory: A Guide oratoryresultinterpretationisessentialforpatientsafety.
to Error Detection and Correction” was published by This book is intended as a practical guide to laboratory
Elsevierin2013andwasintendedasaguidetoincrease professionals and clinicians who deal with erroneous
awareness of both clinicians and laboratory pro- results on a regular basis. We hope this book will help
fessionalsaboutthevarioussourcesoferrorsinclinical themtobeawareofsuchsourcesoferrorsandempower
laboratory tests and what can be done to minimize or themtoeliminatesucherrorswhenfeasibleortoaccount
eliminatesucherrors.Thefirsteditionof thebook had for known sources of variability when interpreting
22 chapters and was well received by readers. Due to changesinlaboratoryresults.
successofthefirstedition,Elsevierrequestedasecond Wewouldliketothankallcontributorsfortakingtime
editionofthebook.Inthisedition,wenotonlyupdated fromtheirbusyprofessionaldemandstowritechapters.
all chapters of the first edition, but also added 9 new Withouttheirdedicatedcontributionsthisprojectwould
chapters so that the second book could be a concise nevermaterialize.Wealsothankourfamiliesforputting
but comprehensive guide for both clinicians and upwithusforthelastyearwhenwespentmanyhours
laboratory professionals to detect errors and sources during weekends and evenings writing chapters and
of misinterpretation in the clinical laboratory and to editingthisbook.Finallyourreaderswillbethejudgesof
preventorcorrectsuchresults. the success of this project. If our readers find this book
Recently, biotin interferences in immunoassays that useful,allthehardworkofcontributorsandeditorswill
utilize biotinylated antibodies have been described berewarded.
which may lead to wrong diagnosis of Grave’s disease RespectfullySubmitted
due to falsely low TSH (sandwich assay that shows AmitavaDasgupta
negative interference due to biotin) but falsely elevated Houston,TX
T3, T4 and FT4 (competitive immunoassays showing
JorgeL.Sepulveda
positive biotin interferences). The Food and Drug
NewYork,NY
Administrationreportedafataloutcomeduetoafalsely
low troponin value as a result of negative interference
xvii
C H A P T E R
1
Variation, errors, and quality in the
clinical laboratory
Jorge L. Sepulveda
Department of Pathology and Cell Biology, Columbia University Vagelos College ofPhysicians and Surgeons,
New York, NY, United States
INTRODUCTION
5. The analytical assaymeasuredthe concentration of
theanalytecorresponding to its “true” level
Recent studies demonstrated that in vitro diagnostic (comparedtoa“goldstandard”measurement)within
tests are performed in up to 96% of patients and that aclinically acceptable marginof error(the total
up to 80% of clinical decisions involve consideration of acceptable analytical error(TAAE)).
laboratory results [1]. In addition, approximately 6. The report reaching theclinician contained theright
40e94%ofallobjectivehealthrecorddataarelaboratory result,together with interpretative information,such
results[2e4].Diagnosticerrorsaccountedfor26e78%of asa reference rangeand othercomments, aiding
identifiedmedicalerrors[5]andnearly60%ofmalprac- clinicians in thedecision-making process.
tice claims [6], and were involved in 17% of adverse
Failureatanyofthesestepscanresultinanerroneous
effects due to medical errors in one large study [7].
ormisleadinglaboratoryresult,sometimeswithadverse
Undoubtedly, appropriate ordering and interpretation
outcomes.Forexample,interferenceswithpoint-of-care
ofaccuratetestresultsareessentialformajorclinicalde-
glucosetestingduetotreatmentwithmaltosecontaining
cisions involving disease identification, classification,
fluids have led to failure to recognize significant hypo-
treatment, and monitoring. Factors that constitute an
glycemia and to mortality or severemorbidity[11].
accurate laboratory result involve more than analytical
accuracyand can be summarized asfollows:
1. Therighttest,withtherightcostsandrightmethod,
ERRORS IN CLINICAL LABORATORY
wasorderedfortherightpatient,attherighttime,for
therightreason[8]:theimportanceofappropriatetest
selectioncannotbeminimizedasstudieshaveshown Errors can occur in all the steps in the laboratory
thatatleast20%ofalltestordersareinappropriate[9], testing process, and such errors can be classified as
upto68%oftestsordereddonotcontributetoimprove follows (see Table1.1):
patientmanagement[10]andconverselytestswerenot
1. Pre-analytical steps, encompassing the decision to
orderedwhenneededinnearly50%ofpatients[9].
test, transmission of theorderto the laboratory for
2. Therightsamplewascollectedontherightpatient,at
analysis,patient preparationand identification,
the correct time, with appropriate patient
sample collection, andspecimen processing.
preparation.
2. Analyticalassay,which producesalaboratory result.
3. Therighttechniquewasusedcollectingthesampleto
3. Post-analytical steps, involving the transmission of
avoid contaminationwith intravenous fluids, tissue
thelaboratorydatatotheclinicalprovider,whouses
damage, prolongedvenousstasis, orhemolysis.
theinformation fordecision making.
4. The sample was properlytransported to the
laboratory,storedattherighttemperature,processed Although minimization of analytical errors has been
for analysis, andanalyzed in a manner that avoids themainfocusofdevelopmentsinlaboratorymedicine,
artifactual changesin the measuredanalyte levels. the other steps are more frequent sources of erroneous
AccurateResultsintheClinicalLaboratory,SecondEdition 3
https://doi.org/10.1016/B978-0-12-813776-5.00001-7 Copyright©2019ElsevierInc.Allrightsreserved.
4
1. VARIATION,ERRORS,ANDQUALITYINTHECLINICALLABORATORY
TABLE1.1 Typesoferrorintheclinicallaboratory. TABLE1.1 Typesoferrorintheclinicallaboratory.dcont’d
PRE-ANALYTICAL ANALYTICAL
Testordering (cid:129) Highanalyticalturnaround (cid:129) Testperformby
time unauthorizedpersonnel
(cid:129) DuplicateOrder (cid:129) Ordermisinterpreted(test (cid:129) Instrumentcausedrandom (cid:129) Resultsdiscrepantwithother
(cid:129) Orderingprovidernot ordered<>intendedtest)
error clinicalorlaboratorydata
identified (cid:129) Inappropriate/outmodedtest (cid:129) Instrumentmalfunction (cid:129) Testingnotcompleted
(cid:129) Orderedtestnotperformed ordered (cid:129) QCfailure (cid:129) Wrongtestperformed
(includeadd-ons) (cid:129) Ordernotpulledbyspecimen (cid:129) QCnotcompleted (differentfromtestordered)
collector
POST-ANALYTICAL
Samplecollection
(cid:129) Reportnotcompleted (cid:129) Reportedquestionable
(cid:129) Unsuccessfulphlebotomy (cid:129) Check-innotperformed(in (cid:129) Delayinreportingresults results,detectedby
(cid:129) Traumaticphlebotomy theLIS) (cid:129) Criticalresultsnotcalled laboratory
(cid:129) Patientcomplaintabout (cid:129) Wrongpatientpreparation (cid:129) Delayincallingcritical (cid:129) Reportedquestionable
phlebotomy (e.g.,non-fasting)
results results,detectedbyclinician
(cid:129) Therapeuticdrugmonitoring (cid:129) Resultsreportedincorrectly (cid:129) Failuretoappendproper
testtimingerror (cid:129) Resultsreportedincorrectly comment
Specimentransport fromoutsidelaboratory (cid:129) Readbacknotdone
(cid:129) Resultsreportedtowrong (cid:129) Resultsmisinterpreted
(cid:129) Inappropriatesample (cid:129) Specimendamagedduring provider (cid:129) Failuretoactonresultsof
transportconditions transport tests
(cid:129) Specimenleakedintransit (cid:129) Specimendamagedduring
OTHER
centrifugation/analysis
Specimenidentification (cid:129) Proficiencytestfailure (cid:129) Employeeinjury
(cid:129) Productwastage (cid:129) Safetyfailure
(cid:129) Specimenunlabeled (cid:129) Date/timemissing (cid:129) Productnotdeliveredtimely (cid:129) Environmentalfailure
(cid:129) Specimenmislabeled:No (cid:129) Collector’sinitialsmissing (cid:129) Productrecall (cid:129) Damagetoequipment
NameorIDontube (cid:129) Labelillegible
(cid:129) Specimenmislabeled:No (cid:129) Twocontradictorylabels
Nameontube (cid:129) Overlappinglabels
(cid:129) Specimenmislabeled: (cid:129) Mismatchrequisition/label results. An analysis indicated that pre-analytical errors
IncompleteIDontube (cid:129) Specimeninformation accountedfor62%ofallerrors,withpost-analyticalrep-
(cid:129) Wrongspecimenlabel misreadbyautomatedreader resenting23%andanalytical15%ofalllaboratoryerrors
(cid:129) Wrongnameontube [12]. The most common pre-analytical errors included
(cid:129) WrongIDontube
incorrectordertransmission(atafrequencyofapproxi-
(cid:129) Wrongbloodtype
mately 3% of all orders) and hemolysis (approximately
Highpre-analyticalturnaroundtime 0.3% of all samples) [13]. Other frequent causes of pre-
(cid:129) Delayinreceivingspecimen (cid:129) STATnotprocessedurgently analytical errorsinclude thefollowing:
inlab
(cid:129) Delayinperformingtest (cid:129) Patient identificationerror
(cid:129) Tube filling error, emptytubes,missing tubes, or
Specimenquality
wrong sample container
(cid:129) Specimencontaminatedwith (cid:129) Hemolyzed (cid:129) Sample contaminationorcollected frominfusion
infusionfluid (cid:129) Clottedorplateletclumps route
(cid:129) Specimencontaminatedwith (cid:129) Inadequatesampletemperature
microbes
(cid:129) Specimentoooldforanalysis Particularattentionshouldbepaidtopatientidentifi-
Specimencontainers cationbecauseerrorsinthiscriticalstepcanhavesevere
consequences, including fatal outcomes, for example,
(cid:129) Nospecimensreceived/ (cid:129) Wrongpreservative/
due to transfusion reactions or misguided therapeutic
Missingtube anticoagulant
(cid:129) Specimenlostinlaboratory (cid:129) Insufficientspecimen decisions. To minimize identification errors, health
(cid:129) Wrongspecimentype quantityforanalysis care systems are using point-of-care identification sys-
(cid:129) Inappropriatecontainer/tube (cid:129) Tubefillingerror(toomuch tems, whichtypically involvethefollowing:
type anticoagulant)
(cid:129) Wrongtubecollection (cid:129) Tubefilingerror(toolittle 1. Handheld devices connected to the laboratory
instructions anticoagulant) information systems (LIS) that can objectively
(cid:129) Emptytube
identifythe patientby scanning a patient-attached
barcode, typically a wrist band.
I. SOURCESOFERRORSINCLINICALLABORATORIES:ANOVERVIEW