Managing POCT Error: The Importance of Quality Control and Risk Management

Transcription

1 Managing POCT Error: The Importance of Quality Control and Risk Management James H. Nichols, PhD, DABCC, FACB Associate Professor of Pathology Tufts University School of Medicine Director, Clinical Chemistry Baystate Health System Man A creature made near the end of the week when God was tired. Mark Twain 2 Medical Errors 2002 Commonwealth Fund report estimated that 22.8 million people have experienced a medical error, personally or through at least one family member Reinforces the 1999 IOM report, To Err is Human Annual costs estimated at $17 29 billion US Agency for Healthcare Research and Quality (AHRQ) estimate medical errors are the 8 th leading cause of death in the US higher than: Motor Vehicle Accidents (43,458) Cancer (42,297) AIDS (16,516) 3 Laboratory Errors A minireview of the literature found the majority of errors occur in the pre and post analytical phases. Bonini P, Plebani M, Ceriotti F, Rubboli F. Clin Chem 2002;48: Many mistakes are referred to as lab error, but actually due to poor communication, actions by others involved in the testing process, or poorly designed processes outside the lab s control. Medical errors occur in prevention, diagnosis and drug treatment occur. Among errors in diagnosis; 50% were failure to use indicated tests, 32% were failure to act on results of tests, and 55% involved avoidable delay in diagnosis. Leape LL, Brennan TA, Laird N, et al. N Eng J Med 1991;324: Unacceptable Results - PPM Deaths / 10 6 enplanements 0.2 Deaths / 10 6 general anesthesia inductions 2-5 Viral transmissions / 10 6 transfusions 29 Results >7 SD / 10 6 automated chem tests 100 Lost bags / 10 6 airplane passengers 5000 Failures / 10 6 proficiency tests 14,000 Difference >5% / 10 6 hematocrit tests up to 190,000 Witte D& VanNess S. Frequency of Unacceptable Results in Point-of-Care TestingArch Pathol Lab Med 123:761, 1999 Need for Quality Laboratory Testing Laboratory testing influences >70% of all medical decisions. >7 billion lab tests conducted in the U.S. annually. Silverstein MD. An approach to medical errors and patient safety in laboratory services. A white paper prepared for the Quality Institute Meeting, Making the Laboratory a Partner in Patient Safety. Division of Laboratory Systems, Centers for Disease Control and Prevention, April

2 POCT Design Flaws POCT Dilemma POCT requires significant operator interaction unlike other medical devices Devices require calibration, quality control Clinicians interpret POCT as equivalent to core lab tests, only faster, and utilize the results interchangeably. More than 50% of POCT is manual, visually interpreted colorimetric tests Often easier to blame a person rather than look to systematic reasons for the error 7 8 Medical Errors The Person Easier to blame a person than an institution for errors. In aviation, 90% of quality lapses are judged to be blameless. The System Active failures due to personal interaction with system Latent conditions, weaknesses in system due to design flaws or heirarchical decisions Need to engineer systems that prevent dangerous errors and are able to tolerate errors and contain their effects Reason J. BMJ 2000;320: Reducing Errors through Automation Newer POCT devices have data management Prompts operator to perform testing same way every time Lock-outs act as internal fail-safes to prevent a patient result if QC fails, not performed or operator is not certified for testing. Feb 2004 CLIAC meeting discussion of possible changes to CLIA waived category suggested that waived tests have fail-safe or failure alert mechanisms whenever possible include QC materials with kits specimens requiring significant manipulation not be waived 9 10 POCT Automation Reduces practice variability (device prompts) Improve patient identification (barcoding) Assists decision-making (internal checks for QC pass, expiration dates, operator ID) When linked to information management can automatically report results, bill and even perform data algorithms to warn of possible errors (delta checks, device flags like inadequate sample, analyzer interferences) Components of a Quality POCT Program Inclusion of laboratory personnel as operators Inclusion of videotape as part of training Involvement of laboratory in training Repeat training and review performance at scheduled intervals Regular comparison of POCT results with clinical laboratory Storage of QC and patient data in POCT device Jones BA, Howanitz PJ. Bedside glucose monitoring quality control practices: A College of American Pathologists Q-probes study of program quality control documentation, program characteristics, and accuracy performance in 544 Institutions Arch Pathol Lab Med 1996;

3 Potential Sources of POCT Error Failure to promptly communicate results (critical values) Misinterpret results Lack of result correlation to clinical symptoms Result in wrong units Failure to acknowledge test limitations Postanalytic Procedure shortcuts Failure to perform QC Inadequate sample volume Analytic Device Errors Select wrong test (POCT vs Core) Patient/specimen misidentification Preanalytic Operator Errors Clotted blood Inappropriate tube or wrong techniques Delays in analysis or transport to lab Devices look simple, misunderstanding test complexity Bubbles in sample Basic Good Laboratory Practices Follows a sound protocol exactly Is conducted by qualified personnel Is controlled by written and understood Standard Operating Procedures Is conducted in adequate facilities Uses calibrated and monitored equipment Has chemical control documentation Has fully retrievable raw data Is overseen by an independent quality assurance reviewer History of Quality Control 1900s Folin & Wu glucose method for quantifying blood sugar: prepare reagents from basic chemicals, perform test using standard procedures Measure reaction product in colorimeter Estimate analyte concentration from std curve 1950 s industrial process control models introduced formal external QC to clinical analyses History of Quality Control Industrial model of quality in analytical process analyze a sample, an external control, containing known amount of measured analyte. CLIA 67 required daily QC as integral part of testing process CLIA 88 - reaffirmed two levels of QC per test per day (blood gases every 8 hours) CAP/JCAHO began to advocate daily QC through inspection and accreditation ISO Medical Laboratories Particular requirements for Quality and Competence CAP now stressing quality systems CAP/JCAHOJCAHO focusing on patient safety and preanalytic, analytic and postanalytic processes Quality POCT Quality Systems Approach CAP checklist revisions for 2006 Reorganized questions under QS approach: Organization Personnel Equipment & Reagents Purchasing & Inventory Process Control (pre, analytic, post) Documents and Records Occurrence Management Internal and External Assessment Process Improvement Service and Satisfaction Safety Fewer questions, each has intent, discussion and examples Quality Systems Organization Personnel Equipment & Reagents Purchasing & Inventory (Reagent Lot Management) Process Control (pre, analytic, post) Documents and Records (Document Control) Occurrence Management Internal and External Assessment Process Improvement Service and Satisfaction Safety

4 QC versus QA Quality Control A system for maintaining established standards in production or in a product by inspection of samples of the product. Quality Assurance A total system for verifying that procedures and records for a test conform with established policies or regulations. Sources of Laboratory Error Environmental: Temperature Humidity Air flow Light intensity Altitude Operator: Improper specimen prep, handling Incorrect test interpretation Failure to follow test system instructions Analysis: Calibration factor incorrect Mechanical failure Systematic Errors Errors which affect every test in a constant and predictable manner Can occur from one point forward or for a limited period of time External, surrogate sample QC does a good job at detecting systematic errors, like: Reagent deterioration or preparation Improper storage or shipment conditions Incorrect operator technique (dilution, pipette setting) Calibration errors wrong setpoint, factors Random Errors Errors which affect individual samples in a random and unpredictable fashion, like: Clots Bubbles Interfering substances External QC does a poor job at detecting random errors unless the error, just by chance, occurs during analysis of the QC sample QC QC and Lab Errors QC 09:00 11:00 01:15 09:00 Line Leak Hemolyzed sample QC daily at 09:00, two levels Line leak occurs at 11:00, dispenses partial reagent causing 25% decrease in values, not detected until next day QC at 09:00. (Systematic Error), must reanalyze all specimens since previous QC at 09:00, the previous day. Hemolyzed specimen (Random error) affects one sample External Quality Control Advantages Analyzed like patient specimen Can detect drift, imprecision, chemical deterioration Disadvantages Patients can be reported before problem detected When problem detected must go back and reanalyze patients since last good QC Need to get to fully automated analyzers that eliminate errors upfront, provides assured quality with every sample

5 Manufacturer Checks Alternative QC Some devices have internal checks which are performed automatically with every specimen: Development of a line (Pregnancy test, Occult blood) Sensor signal (blood gas analyzer, clots) Flow resistance and liquid sensors (clots or bubbles in analyzer pipettes) Other checks engineered into device: Temperature indicator in shipping carton Barcoding of reagent expiration dates (prevents use) Lockout features that require successful QC Disposable analyzer cuvettes/pipette tips (carry-over) Quality Management Traditional approach perform two levels of external, liquid surrogate sample as quality control (QC) of testing process. This controls for analytic, operator and environmental effects. Most effective on systematic errors that linger in time. Other types of random error, occur sporadically and are harder to detect by this approach. Alternative QC internal, automatic checks performed by the device may be better at detecting random errors, since these checks are performed with each patient test Negative 1 line Positive 2 lines Alternative, Non-Surrogate Sample Quality Control Quality POCT Hazard Analysis and Risk Mitigation NCCLS/CLSI EP18 Quality management for Unit Use Testing. Defines a user-manufacturer quality partnership and specific areas of responsibility Error Matrix tables covering potential sources of pre, analytic, and post errors Direction of Sample Migration Potential Sources of Error Air bubbles Improper Reagent Shipment CLSI EP18 Error Matrix Nature of Impact Result error Freezing Erratic ph Device Capability Auto bubble detection Freeze indicator in packaging Lab Requirements Staff training on Error codes Policy to check indicator Quality Monitor Audit error codes by number Check indicator Frequency of monitor Quarterly or at lab discretion On arrival each shipment New CLSI Documents in Draft EP22 Principles of Manufacturer s Validation of Risk Mitigation Using Quality Controls - Greg Cooper, Chairholder This document describes the principles, and gives procedural examples, for validation of the capability of internal, manufacturer quality controls to mitigate the identified risks. Companion Document EP23 Laboratory EQC Protocols Based on Manufacturer s Risk Mitigation Information and the Laboratory s Environment James H. Nichols, Ph.D., Chairholder Labs will receive guidance enabling them to develop effective, costefficient QC protocols that will ensure appropriate test quality based on the technologies selected by the lab and reflective of lab s unique environmental aspects. Labs will receive guidance to develop QC processes and procedures to: Reduce negative impact of test system s limitations, while considering lab environmental factors like personnel competency, temp, etc. Monitor immediate and extended test performance

6 Summary Medical errors are a concern given the number of tests performed by the laboratory While it is easier to blame a person, we need to design systems that prevent errors Changes to international and US laboratory standards and regulations are focusing on quality systems that incorporate risk management principles and use of both external and internal (alternative) QC processes Each device is unique and error prevention must be tailored to the potential for error on each device POCT There is no such thing as foolproof, for a sufficiently talented fool Dr. C. Rauch - My Distinguished Colleague