Presentation on theme: "Day to Day Management of Quality Control"— Presentation transcript:
1Day to Day Management of Quality Control Donna Walsh M.S. MT(ASCP)Deaconess HospitalBoston, MA
2Why We Do Quality Control Clients of laboratories services see the test results we produce as information and expect that information to be flawless, a very tall order. Statistical Quality Control practices is one of the tools of the trade utilized to approach reasonable levels of flawlessness.
3Why We Do Quality Control We are all familiar with classical approaches to quality control and the frustrations involved when these approaches fail and we need to troubleshoot methodology before releasing results.
4Goal and ObjectiveThis talk will review the basics of statistical quality control and some 'nuts and bolts' solutions to common QC problems.Case studies will be used to illustrate effective strategies.
5Goals of those Attending Today Improving Day to Day QC Decisions & Documentation and Review of QCTrying to get the days work reported out
6Health Care Today Emphasis today is on cost containment Laboratories have become cost centers as opposed to revenue centers.QC costs involve cost of QC material (special controls can be very costly)QC costs involve rework of out of control runs. (labor, reagent and control cost)
7How Did We Get Here?Levy-Jennings Plots were adapted from industrial use and have been in use to this very day since the 1960’s
8Classic Quality Control Principles of Statistical QCControl Solutions are used to make Control MeasurementsControl Measurements validate Unknown MeasurementsStatistical Measurements Provide Guidelines for Acceptable Control Measurements
11Ever Seen a QC Chart Like This? Dot chart of the 90’s
12Multi-rule Quality Control Based on the concept that improved error detection is provided by selecting multi-rules over single-rule control procedures.Widely used multi-rule control procedure is the one recommended by Westgard
13Westgard Multi-Rule Quality Control Scheme dataNo12sIN-CONTROL ACCEPT RUNNoNoNoNoNo13s22s41sR4s10XYesYesYesYesYesOUT-OF-CONTROL REJECT RUN
14Available Options Classic QC Multi-Rule very visual tedious manual record keepingoften available as an on-line QC package for many automated systemsMulti-Rulebetter error detectionmore cumbersome for operatoreasily adaptable to computer analysis
15Practical “Nuts & Bolts” Options Include Analytical Performance in Control Parameter (mean & SD) DecisionsUse NCCLS EP-5 to evaluate precision.Adapt Control Measurement Frequency to Testing NeedsSet Medically Useful Control ProceduresControls Levels at Medical Decision PointsConsider Control Measurements Quality ChecksKeep track of lot numbers, calibrations & maintenance proceduresUse this procedural information to assign causes to failures of quality checks
16Case Studies .... practical QC Incorporating NCCLS EP-5 data into QC decisions
17Case Studies .... practical QC Adapt Control Measurement Frequency to Testing NeedsNCCLS EP-5 calls for 2 replicates per run, 2 runs per day for 20 day. Adapt to testing situation - Example: Stat Lab has three shifts and three controls for OximetryAdopt CLIA definition of 24 hour = one run and assay 3 reps, for assay of new lot of controlImplement different QC levels on each shift for periods of stable operation.
18Practical ‘Nut & Bolts’ HINT Many of today's testing procedures have much improved analytical performance. You can take advantage of this improved accuracy and precision in the design of your QC protocol.
19Case Studies .... practical QC Set Medically Useful Control ProceduresExample: Digoxin
20Case Studies .... practical QC Set Medically Useful Control ProceduresExample: pH Reference Range is (range = 0.07)Control Material A; standard deviation = ; /- 2 sd = 0.056Control Material B; standard deviation = ; /- 2 sd = 0.020Control Material B is more costly than Control material ABut it is costly to walktoo fine a line...
21Practical ‘Nut & Bolts’ HINT Set the % CV tight or use a control protocol that has improved precision at Clinically Significant Decision LevelsOr put differently, make sure you have an appropriate target for the situation.
22Case Studies .... practical QC Consider Control Measurements Quality ChecksKeep track of lot numbers, calibrations & maintenance proceduresUse this procedural information to assign causes to failures of quality checksBest way to document assignable causes of mean & sd changeslot numbers
23Case Studies .... practical QC Example: Preventative Maintenance Appropriate for WorkloadDrugs by Fluorescent Polarization
24Case Studies .... practical QC Increase PM frequency
25Case Studies .... practical QC Example: new lot number of reagent
26Case Studies .... practical QC Example: new lot number of reagentshift in QC values correlated with change in lot of reagent.check to see if there is a shift in unknowns (samples) or standardsmatrix effect if shift is only in control samplesadjust QC mean to account for shift and avoid unnecessary repeat work.Lot numbersxx0226xx0228
27Case Studies .... practical QC Long standing shifts may not be obvious until a lot change causes a shift out of controlCheck Year to Date and or lot to date QC for any shifts or trends.lot change
28Case Studies .... practical QC Example: Glucose - shift in current month away from year to date when new electrode used.
29Case Studies .... practical QC Example: Change in QC post calibration of new lot of CalciumLot related shift post cal on Recal on 5-20 due to bias in pt. checkscalibration done
30Case Studies .... practical QC Example of shift with no assignable causeLithium by ISETrouble shooting- new control- recalibration- new electrode- fresh reagentsNOTHINGWORKED!!!
31Case Studies .... practical QC Lithium Statistical QC information
32Practical ‘Nut & Bolts’ HINT Running control samples is a check on quality; they do not control quality. You must do that yourself.There is NO such thing as a QC Crystal BallREPORT RESULTS!
33Recommendations View the test results we produce as information Include Analytical Performance in Control ProtocolsSet Medically Useful Control ProceduresMake use of on-line QC packagesfacilitates statistical quality control calculationsprovides visual dot charts for operators
34Recommendations Consider Control Measurements Quality Checks Keep track of information that could validate a change in the statistical QC parametersChange QC parameters promptly when the situation warrentsUse Patient Check Data to help in QC decisions
35Benefits Accurate and Reliable Reporting of Patient Test Data Well Documented Quality Control ProgramDay to Day and Cumulative QC data will be more useful.