Quality Assurance in Histopathology
Dr Dinah V ParumsM.A.,PhD,B.M.,B.Ch.,FRCPath.,FCCP
Consultant Histo/Cytopathologist, 2001U.K.
Objectives Satisfy RCPath requirements:
Trainees will have some knowledge of QC, QA, CQI and professional QA as applied to Anatomic/Surgical Pathology
Success at Royal College exams Enjoy a safe professional practice Prepare for lab management role
QA in AP
QA program structure Driving forces CPA general requirements Local reporting structure
Core QA elements Autopsy Cytology Surgical Pathology
Introduction to error management in anatomic pathology
QA: driving forces Mandated for lab accreditation
Accreditation: CPA Assessment: EQA
Financial Incentive Cancer Unit/Centre status Coroner’s Office requirements
Medical “standard of care” Litigation protection (CMPA) Complaint/license protection (CPSO) Hospital privileges
Technical “good lab practices”
Clinical Pathology Accreditation (CPA) Specifies general organizational
structure of Lab QA program (quality manager, manuals)
Extensive documentation requirements Personnel qualifications & training Equipment, reagents, supplies Communications & LIS Specimen handling & reporting
Etc.
CPA QA requirements General (apply to all lab areas)
“appropriate quality indicators monitored…” “QC processes shall consist of goals, policies,
procedures, tolerance limits and corrective actions…”
[labs] “shall establish clinically appropriate turnaround times for each examination”
Specific (apply to individual labs) Practice standards (e.g. surgical path specimen
containers shall have adequate volume of fixative)
Activities (e.g. HSIL pap/histology correlation)
Core QA elements: Autopsy TAT monitored weekly and audited semi-
annually (std 80% in 8 wks, max. 10 wks) Case rounds (aut conf, MMR, ML rds) Provincial centralized forensic case review CPA requirements
Consent, identification, paperwork Block & slide retention times (20yrs adult, 50
yrs child) Report to include gross, micro, major findings,
information needed to determine cause of death
Core QA elements: Cytology CPA mandated activities
Overdue case tracking 10% negative pap’s rescreened before sign-out
(targeted and random) 3 yr back rescreen for new HSIL+ Cyto-histo correlation (pap HSIL, non-gyne) Diagnostic category rates (neg, ascus, sil) TAT (monitored semi-annually, 2wks for paps, 3
days for non-gyne) False negative rate (rescreen SIL : initial neg)
EQA slide surveys
Core QA elements: Cytology CPA standards
Separate screening area Instructions for specimen collection to providers Requisitions include clinical & pap history, LMP Accepted staining methods used Contamination prevention procedures Separate gyne/non-gyne staining All paps screened by techs Techs may finalize neg/benign change only Abnormal areas marked & tech comments retained Pathologists provide feedback to techs
Core QA elements: Surg Path CPA mandated activities
Overdue case tracking TAT (monitored semi-anually, std 2
days for bx’s, 3 days for routine + extra for IP/specials)
EQA IP and special stain testing Patterns of practice surveys
Core QA elements: Surg Path “Standard of care activities”
Frozen section/final diagnosis correlation Addendum/amended correlation Mandated second review rate Case rounds/tumour board review rate
“Good lab practices” activities “Incident” reporting and tracking
labeling, pickups, no tissue, lost tissue etc Daily staining QA log Customer satisfaction surveys
Core QA elements: Surg Path CPA mandated standards
Adequate volumes of fixative Labels have name, unique ID & tissue site FS manual covers specific specimen types FS results communicated directly and recorded Addendums for special studies Appropriate IP controls IP slides kept with other case slides Log time slides delivered to pathologists Document IP slide results Pathologists evaluate slide quality List of specimens on report
Core QA elements: Surg Path CPA mandated standards (cont’d)
Report includes: gender, DOB, pt location, attending & submitting
MD, dates of procedure, accessioning & reporting Clinical history Gross description including block list FS diagnosis Microscopic as relevant Final diagnosis (indicate if gross exam only) Pathologists signature or electronic equivalent
Core QA elements: Surg Path CPA mandated standards (cont’d)
Lab has appropriate slide, block, report and tissue retention guidelines
Wet tissue 4+ wks after report issued Blocks and reports :
20 yrs for adults 50 yrs for children
Slides : 10 yrs for adults 10 yrs after 18th birthday for children
Introduction to Diagnostic Error Management in Anatomic Pathology
No generally accepted definition of what an “error” is
Definition issues include: Hindsight bias “Expert” opinion Viewpoint
Clinical: significant vs insignificant Legal: negligent vs reasonable
Error Classification Planning: wrong plan, right execution Cognitive: right plan, problem in
execution Slips & Lapses
Slip: error of commission (e.g. pick up slide from wrong case, mislabel slide)
Lapse: error of omission (e.g. miss a slide, miss a gross lesion, don’t label block, forget to include margin status in report)
Mistakes: knowledge, rule and “thought” based errors
Mistakes Lack of knowledge
Unaware of an entity, of classification or process rules
Misinterpretation of data Unable to apply good data and good
rules Application of bad rules
Inevitable disagreements resulting from bad rules considered “errors” (e.g. ASCUS)
More frequent Near misses If notice error can
recognize and fix Self corrected Very difficult to
eradicate
Less frequent May recognize a
problem but not consider it an error
Not self corrected Easier (but still
difficult) to eradicate
Slips/lapses vs Mistakes
Approaches to error management Use systems rather than person
approach Recognize human fallibility and structure
operational systems around this Safe systems
Simplify tasks, add visual cues, reduce reliance on memory
Design for reversibility and recovery Stress educational rather than punitive
environment Monitor errors and near misses and respond
Medical-legal aspects of error Malpractice
Injury resulting from negligence Negligence
Medical practice which falls below the “standard of care”
Standard of care Peer based in theory although in
practice often expert based “best practice”
Pathology malpractice Low frequency of claims
8.3% of U.S. pathologists per year: average pathologist has one claim every 12 years (compare to 55% of U.S. neurosurgeons per year)
Probably about half these rates in U.K. High success of claims High severity (cost) of claims,
particularly in U.S.
Pathology Claims Analysis
15% “random” 85% “systematic”
Mainly cancer diagoses: 63% false negative (FN), 22% false positive (FP)
Top 5 types (57% of claims) were: breast (15%) FP = FN melanoma (13%) 95% FN Pap smears (12%) 98% FN gyne (9%) 85% FN, 42% ovarian tumours operational (6%) specimen mix-ups & losses, typo’s
etc
Pathology Error Management Mandatory prospective second review
of high risk cases documented in report Retrospective review at tumour boards
and teaching rounds with case tracking Subspecialty sign-out Synoptic and template based reporting
Conclusion: QA in Histopathology Driven by
Structured accreditation requirements Unstructured expectations of good medical care
Includes Standards of lab practice Quality activities (audits, indicator monitoring) A systems based error management program
targeting high risk operational and diagnostic areas