Laboratory Errors

Laboratory Errors Whom to Blame.. Reproducibility of lab tests continues to be an issue of major concern

Mehnaaz S. Khuroo MD (Pathology) Assistant Professor Department of Pathology

Govt. Medical College, Srinagar website: www.drkhuroo.in

Laboratory Errors Whom to Blame..

Laboratory Errors Whom to Blame..

Laboratory Errors Whom to Blame.. Lab errors- definition Definition: an error which occurs at any part of laboratory cycle, from ordering tests to reporting and interpreting the results and action thereof (multiple steps) Risks: No result is better than bad result Frequency: One error in 300-1000 events, 900-2074 patients and 214-8316 laboratory results

Laboratory Errors Whom to Blame.. Lab errors-Risks Patientcare: Inadequate & inappropriate patientcare, morbidity, mortality

Public health: Undetected outbreaks causing a disaster

Resources: repeat testing, waste of resources

Laboratory Errors Whom to Blame.. Three phases of lab tests Pre-analytical phase: ordering, patient preparation, specimen collection/handling, storage/transport and processing prior to analysis Analytical phase: testing of the specimen Post-analytical phase: reporting results, transmission to client/physician, interpretation, actions taken, follow-up, retesting

Laboratory Errors Whom to Blame.. Error sites%

Pre + Post = 90%

Flyers

Modified from Plebani et al 2006

Laboratory Errors Whom to Blame.. Pre-pre-analytical phase: physicians role Misuse of laboratory services: excessive, unnecessary and inappropriate/wrong requests (under strict scrutiny) Magnitude: vary widely, 11-70% biochemistry/hematology, 5-95% urine screen, 17.4-95% cardiac enzymes/thyroid profile Risks: delays treatment planning, resource waste, issues of incidental findings leading to unnecessary health concerns Control: Combined efforts, continuous monitoring, consultancy, evidence based guidelines

Laboratory Errors Whom to Blame.. Pre-pre-analytical phase: patient’s role Inability to comply with fasting for selected tests, example lipids (# wazwan) Many tests have diurnal variation and this needs to taken in to account while collecting and interpreting results, example cortisol, Growth hormone, thyroid profile etc. Therapeutic drug monitoring need peak and trough collection times It is important that patients stick to normal carbohydrate diet for several days prior to some tests, example Glucose tolerance test

Exercise can influence many lab tests like CBC, urinalysis, CK, KFT, liver enzymes, etc.

Laboratory Errors Whom to Blame.. Pre-analytical phase errors Wrong patient identification Incorrect phlebotomy technique Wrong collection technique Inappropriate specimen transport

Faulty specimen processing

Laboratory Errors Whom to Blame..

Patient identification When identifying the patient, have them provide their full name (first, middle and surname), address (mailing address), identification number, date of birth and contact number (including contact of caregiver). Hospital inpatients should be wearing an identification band with the above information, which the phlebotomist should confirm before the venipuncture. Phlebotomist must identify himself along with his contact number.

Laboratory Errors Whom to Blame.. Wrong patient identification Errors in correctly identifying a patient are indefensible Wrong name can occur by not following proper name code (first, middle, surname), copying name from bracelet, identification by relative/friend Specimens must be labeled by numbers by pasting bar codes. Manual labeling of ID numbers often lead to errors and lead to disasters in lab testing

All specimens must have requisition forms. Both tubes and collection forms must have bar code pasted on either Inability to identify the date or time of specimen collection, his telephone number and lack of phlebotomist’s initials and phone number

Laboratory Errors Whom to Blame.. Errors in phlebotomy technique Venous access difficulties Use of inappropriate needle size or smaller evacuated collection tubes Faulty tourniquet application leading to hemoconcentration and faulty lab results Faulty cleansing material or technique Correct collection system namely vacutainers for large veins and syringes for small fragile veins Wrong order of draw can lead to erroneous test results due to contamination with additives from previous collection tubes [correct order-culture, citrate, SST, heparin, EDTA, Fluoride]

Laboratory Errors Whom to Blame.. Specimen transport-errors thereof Some specimens need immediate transport to laboratory like blood gases Some specimens need to be analyzed within specified time (around 4 hr.), example CBC Specimens for serum or plasma chemistry need to be centrifuged and separated within 2 hr. of collection and then can be transported Specimens should be transported at proper specified temperature, example ice (ABG, NH3), warm (cryoglobulins), chilled (most specimens sent to distant lab) Some specimens need to be protected from light during transport, example bilirubin, vit D etc.

Laboratory Errors Whom to Blame.. Analytical phase Analytical reliability has been established through standardization, automation and technological advances Continued use of manual lab testing is an important source of lab errors and should be replaced by fully automatic testing It is not fair to compare results obtained from fully automatic equipment with manual or semi-automatic equipment There are some remaining issues in analytical phase of specimen testing and refer to calibration errors in medical decision making , contamination rates in nucleic acid testing and analytical interferences in immunometric assays All rapid point-of-care testing needs to assessed in light of well done published data or meta-analysis studies.

Laboratory Errors Whom to Blame.. Analytical phase- common causes of errors QC, EQA not followed; Equipment malfunction; Individual responsibilities not defined; Staff training and CME issues No written procedures or established documented algorithm not followed

Incorrect timing of test; Results reported when control results are out of range Improper dilution and pipetting of sample or reagents Reagents stored inappropriately or used after expiry date Transcription errors

Laboratory Errors Whom to Blame.. Post-analytical phase Laboratory-based phase Steps: Verifying lab results, feeding data in to lab information system, communicating data to clients [patients/physicians], Errors: wrong validation (# Lab chief signatures), delayed release of results, results not reported, results sent to wrong clients, wrong data entry and wrong results sent to clients, inaccurate reference range, results ineligible

Out-of-laboratory phase Steps: Clinicians receives, reads and interprets results, makes decisions based on the results, Errors: Inability to access alert results in time, complex tests difficult to interpret, inability to evaluate all results due lack of time and volume of data,

Laboratory Errors Whom to Blame.. Common reported lab errors Patient identification errors

Proficiency test errors

Lost sample

No action on out of range results

Sample delayed in transit

False negative result

Contaminated sample

Late reports

Wrong test ordered or performed

Missing reports

Test performed inconsistent with written procedure

Complaints / lab accidents

Error rates in the total testing process, as shown in the Q-Probes studies performed by the American College of Pathologists

Laboratory Errors Whom to Blame.. Laboratory errors and patient outcome Author yr.

Number of errors

Effect on patient outcome

Inappropriate care

Ross et al 1989

336

30

7

Nutting et al 1996

180

27

12

Plebani et al 1997

189

26

6.4

Laboratory Errors Whom to Blame.. Suspect lab errors Lab values which are very high or low Lab values which significantly vary from previous results

Results which do not correlate with patients clinical status Values reported on hemolysed samples or those reported after long storage or faulty collection procedure

Laboratory Errors Whom to Blame.. Reporting of errors Cycle of event (pre, intra, post-analytical phase)

Recognition where event has been generated- internal or external to laboratory Responsibility for event-latent or active, cognitive or non-cognitive

Preventability-yes or no

Impact on patient-care-none, minimal, inappropriate treatment or diagnosis, morbidity, mortality

Laboratory Errors Whom to Blame.. Actions plan for suspected lab error Incident report (written from clinician to lab) Check for transcription errors Repeat study on original sample

Repeat determination on a new sample Error confirmed, results to be reported to physician; replace recorded erroneous results with new corrected results If no error found, review clinical findings, drug history, unsuspected disease, etc.

Laboratory Errors Whom to Blame.. Lab errors.. The human role in sample collection, transport, analysis, reporting and interpretation makes elimination of errors associated with laboratory testing unrealistic However, good practices and compliance with strategies for error prevention can lead to a substantial reduction in laboratory errors

Laboratory Errors Whom to Blame..

Word of caution..

No test is better than a wrong test Thank you