Quality Management Flashcards
Public and private pressures to contain healthcare costs are accompanied by pressure to improve quality.
Seemingly contradictory pressures for both (2) require that healthcare organizations adopt new systems for managing quality.
Because of these pressures, other industries implemented_______
cost reduction and quality improvement (Ql)
Total Quality Management (TQM)
The principles and concepts of TQM have been formalized into a quality management process.
The traditional framework for managing quality in a healthcare laboratory has emphasized the establishment of (3)
quality laboratory processes (QLPs)
quality control (QC)
quality assessment (QA).
includes analytical processes and the general policies, practices, and procedures that define how work is done.
QLP - quality laboratory processes
emphasizes statistical control procedures but also includes non-statistical check procedures, such as linearity checks, reagent and standard checks, and temperature monitors.
QC - Quality control
as currently applied, is primarily concerned with broader measures and monitors of laboratory performance, such as (4)
QA - quality assessment
(1) turnaround time (TAT)
(2) specimen identification
(3) patient identification
(4) test utility
T or F
Measuring performance by itself improve performance and often does not detect problems in time to prevent negative outcomes.
False!
Quality assurance requires that causes of problems be identified through ____ and eliminated through______, or that____ be able to detect problems early enough to prevent their consequences.
QI
quality planning (CP)
QC
“scientific method”
PDCA cycle (Plan, Do, Check, Act).
____provides the planning step
____establishes standard processes for doing things
________ provide measures for checking how well things are clone
_____provides a mechanism for acting on those reasures.
QP
QLP
QC and QA
QI
The purpose of a _______ is to evaluate the pathophysiologic condition of an individual patient to assist with diagnosis and/or to monitor therapy.
clinical laboratory test
The total error of a result is influenced by the following;
• Biological/physiologic variability within an individual
• Pre-analytic variability in sample collection, transportation, processing, and storage
• Analytic variability in test performance
• Interfering substances such as drugs or retabolic components
Quality control (QC also called______)
statistical process control
process to periodically examine a measurement procedure to verify that it is performing according to preestablished specifications.
Quality control
It involves the systematic monitoring of analytic processes in order to detect analytical errors that occur during analysis and to ultimately prevent the reporting of incorrect patient test results.
Quality Control
Quality Control Goals
• Error Detection
• Error Prevention
• Measure performance (Bias, Imprecision, Total Error)
• Monitor performance
• Validate performance
In general, monitoring of ______ methods is performed by assaying stable control materials and comparing their determined values with their expected values.
analytic methods
The expected values are represented by intervals of acceptable values with upper and lower limits, known as________.
control limits
When the expected values are within the_________, the operator can be assured that the analytic method is properly reporting values.
However, when observed values fall outside of the ______, the operator can be notified of possible problems and further analysis of the method can be made before potentially erroneously reporting patient results.
control limits
The principles of statistically analyzing QC were initially applied to the clinical laboratory in the 1950s by________
Levey and Jennings
Specimens analyzed for QC purposes are known as_____
QC materials
These materials must be available in sufficient quantity to last at least a year and aliquoted in stable form.
QC materials
______ should be the same matrix as the specimens actually to be tested.
For example, a glucose assay performed on serum should have ______ that are prepared in serum.
QC materials
_______ should span the clinically important range of the analyte at appropriate decision levels.
For example, sodium QC materials might be tested at 130 and 150 mmol/L, representing cutoff values for hyponatremia and hypernatremia, respectively.
Control material concentrations
QC for general chemistry assays generally use_____ levels of control, while immunoassays commonly use____.
two
three
T or F
Today, laboratories more often purchase control materials from companies that manufacture products for QC, instead of preparing the materials themselves.
True
QC materials are often ______ for stability and can be reconstituted in specific diluents or matrices representing urine, blood, or CSF.
lyophilized (dehydrated to powder)
give expected target ranges, often including the mean and SD using common analytic methods.
Assayed materials
these products are more expensive because of the additional characterization, they allow another external check of method accuracy.
Assayed materials
Because most commercially prepared control materials are lyophilized and require reconstitution before use, the_____ should be carefully added and mixed.
Incomplete mixing yields a partition of supernatant liquid and underlying sediment and will result in______ control values.
diluent
incorrect
the reconstituted material will be more _______ than the actual patient specimen.
turbid (cloudy)
_____ do not require reconstitution but may behave differently from patient specimens in some analytic systems.
It is important to carefully evaluate these ______ with any new instrument system.
Stabilized frozen controls
A common method to assess the determination of control materials over time is by the use of a______
Levey Jennings control chart.
_______ graphically represent the observed values of a control material over time in the context of the upper and lower control limits.
Control charts
When the observed value falls with the control limits, it can be interpreted that the method is performed adequately. Points falling outside the control limits may suggest that problems may be developing.
Control limits are expressed as the________ (formula)
mean +/-SD
The______ system in the clinical laboratory is used to monitor the analytic variations that can occur.
QC
The QC program can be thought of as a three-stage process:
- Establishing allowable statistical limits of variation for each analytic method
- Using these limits as criteria for evaluating the QC data generated for each test
- Taking action to remedy errors when indicated
(3) actions to remedy errors when indicated
a. Finding the cause(s) of error
b. Taking corrective action
c. Reanalyzing control and patient data
The distribution of error is assumed to be _______ (shape)
symmetrical and bell shaped (Gaussian)
are set to include most observed values (95%-99.7%), corresponding to the mean +/- 2 or 3 SDs.
Control limits
the distribution is symmetric-meaning half the values fall to the left of the mean, and the other half fall to the right–and the symmetrical shape is often referred to as a “_____”.
bell curve
Much of the area–68.3%-under the
“normal” curve is between _____
+/-1 SD
Most of the area–95.4%-under the “normal” curve is between_____
+/-2 SDs
almost all of the area-99.7%-under the “normal” curve is between
+/- 3 SDs
Observation of values in the distribution tails should therefore be rare
_____ for 2 SDs
_____for 3 SDs
1/20
3/1,000
Analytic methods are considered _____ if a symmetrical distribution of control values about the mean are seen and few values outside the 2 SDs
(25) control limits are observed.
Some laboratories define a method _____ if a control value exceeds the 2s limits.
in control
out of control
Other laboratories use the 2s limit as a_____ limit and the 3s limit as an____ limit.
In this particular case, a control point between 2s and 3s would alert the technologist to a_______, while a point greater than 3s would require a______
warning
error
potential problem
corrective action.
______ can occur because of the control limits set and not actually identify a problem with the assay.
The use of a_____ control limit reduces the false rejection problem, with a corresponding loss of error detection.
False rejections
3s
Plotting data in_____ are an easy way to visualize distribution.
histograms
The spread represents the relationship of all the data points to the______.
There are three most commonly used descriptions of spread:
mean
(1) range
(2) standard deviation (SD)
(3) coefficient of variation (CV)
The easiest measure of spread to understand is the_____.
It is simply the largest value in the data minus the smallest value, which represents the extremes of data one might encounter.
range
is the most frequently used measure of variation.
Standard deviation (also referred to as “s.” or SD)
describes the distribution of all data points around the mean.
SD
Another way of expressing SD is in terms of the____.
It is calculated by dividing the SD by the mean and multiplying by 100 to express it as ______
CV
percentage
The____ simplifies comparison of SDs of test results expressed in different units and concentrations.
The ____ is used extensively to summarize QC data.
CV
The CV of highly precise analyzers can be lower than____
1%
Clinicians use the result and compare with a______ range to make diagnosis.
reference
T or F
Clinicians may also use current result and compare with previous result to make diagnosis or monitor progress of treatment.
True
is the “true” value of the constituent; thus, it refers to the closeness of a measured value to a standard or known value.
Accuracy
refers to the closeness of two or more measurements to each other.
Precision
It is also the degree of replication or reproducibility.
Precision
The difference between test- and reference-method results is called____.
error
There are two kinds of error:
random
systematic
______ error is present in all measurements and can be either positive or negative.
Random
______error can be a result of many factors including instrument, operator, reagent, and environmental variations.
Random
error influences observations consistently in one direction (higher or lower).
Systematic
The measures of slope and y-intercept provide estimates of the
systematic error
Systematic error can be further broken down into (2)
constant error and proportional error
________ error exists when there is a continual difference between the test method and the comparative method values, regardless of the concentration.
Constant systematic
______ error exists when the differences between the test method and the comparative method values are proportional to the analyte concentration.
Proportional
The “multi-rule” procedure was developed by (2) to further judge whether control results indicate out-of-control situations.
Westgard and Groth
These rules established a criterion for judging whether an analytic process is out of control.
“multi-rule” procedure
indicate the number of control observations per analytic run, followed by the control amount in subscript.
Control rules
One control observation exceeding the mean +/- 2s. A warning rule that initiates testing of control data by other rules.
1 2s
One control observation exceeding the mean +/- 3s. Allows high sensitivity to random error.
1 3s
Two control observations consecutively exceeding the same + 2s or - 2s.
Allows high sensitivity to systemic error.
2 2s
One control exceeding the +2s and another exceeding the - 2s. Allows detection of random error.
R 4s
Four consecutive control observations exceeding +1s or -1s. This allows the detection of systemic error.
4 1s
Ten consecutive control observations falling on one side or the other of the mean (no requirement for SD size). This allows the detection of systemic error.
10x
This is a warning rule that is violated when a single control observation is outside the ‡ 2s limits.
This rule merely warns that random error or systematic error may be present in the test system.
12s
This rule identifies random error. Any QC result outside + 3s violates this rule.
1 3s
This rule indicates systematic error. Two consecutive controls exceed the mean by +/- 2SD
2 2s
If there is at least a 4s difference between control values within a single run, the rule is violated for random error.
R 4s
This indicates systematic error.
4 1s
10x
SOURCES OF SYSTEMATIC ERRORS
• Improper alignment of sample or reagent pipettes resulting to change in reagent and calibrator volume
• Drift or shift in incubator chamber temperature, deterioration of photometric light source.
• Change of Calibration /reagent lot
• Deterioration of reagent/calibrator/control product while in use, storage or shipment
• Incorrect handling of control product
• Inadequate storage of reagent or calibrators/control products
• Change in test operator
SOURCES OF RANDOM ERRORS
• Power Supply
• Double pipetting of control sample
• Misplacement of Control sample within the run
• Random air bubbles in reagent or sample pipette system
• Incorrect reconstitution of the control product
• Inappropriate Storage of control
• Inadequately mixed reagents
• Individual operator variation in pipetting, timing, etc.
The following errors can be detected in L-J chart: (2)
Shift
Trend
This is defined as abrupt changes in the control mean.
Shift
in QC data l, it represent a sudden and dramatic positive or negative change in test system performance.
Shift
Shifts may be caused by:
• Sudden failure or change in the light source
• Change in reagent formulation
• Change of reagent lot
• Major instrument maintenance
• Sudden change in incubation temperature (enzymes only)
• Change in room temp. or humidity
• Failure in sampling system & reagent dispense system
• Inaccurate calibration/recalibration
This indicates a gradual loss of reliability in the test system.
Trend
Trends may be caused by:
• Deterioration of the instrument light source
• Gradual accumulation of debris in sample/reagent tubing
• Gradual accumulation of debris on electrode surfaces
• Aging of reagents
• Gradual deterioration of control materials
• Gradual deterioration of incubator chamber temp.
• Gradual deterioration of light filter integrity
• Gradual deterioration of calibration
