Cls 265 Exam 2

Front 1

Mean

Back 1

- the average of a group of numbers

- symbol is X bar

- use the mean value to perform other statistical tests on the group

- one indicator of "central tendency"

Front 2

Central Tendency

Back 2

- distribution of data around a central value

Front 3

Median

Back 3

- indicator of central tendency

- central number in a group of numbers when the numbers are arranged in sequential order

- an equal quantity of numbers is greater than the median value and less than the median value

- may or may not be the same as the mean

Front 4

Mode

Back 4

- the number that occurs most frequently in a group of numbers

- there is bimodal, trimodal, etc.

Front 5

Indicators of Central Tendency

Back 5

- Mean and median

Front 6

Accuracy

Back 6

- correctly reflects the "true value" of the result

- imagine a "target" value that should be obtained for an analyte

Front 7

Precision

Back 7

- occurs when, after repeated analysis, the same result is achieved

Front 8

In the lab, how accurate and precise do we want to be?

Back 8

- we want results that are both accurate and precise

- when a method is both accurate and precise, it is reliable

Front 9

Sensitivity

Back 9

- a quality of a method that allows for the detection of very small amounts of analyte in a sample

Front 10

Specificity

Back 10

- the quality of an analytical method to discriminate the analyte of interest from other substances present in the sample

Front 11

Variance

Back 11

- indicator of the precision of a group of numbers

- symbol is s squared

- indicates how close together, or how precise, the numbers within a group are

- a group of numbers with a large variance would be expected to have a wide range of values

- a group of numbers with a small variance would be expected to have numbers that are very close in value

- the smaller the variance a group of numbers, the more precise they are

- how we measure precision

Front 12

Standard Deviation

Back 12

- the most frequently used measure of precision

- symbol: s

- square root of the variance

Front 13

Probabilities Associated with Standard Deviation

Back 13

Statistically, if a sample is analyzed 30 times and the mean and SD established for the results are:

- 68.2% of the time, the results will fall within plus or minus 1 SD from the mean

- 95.5% of the time, the results will fall within plus or minus 2 SD from the mean

- 99.7% of the time, the results will fall within plus or minus 3 SD from the mean

- 68-95-99.7 rule

Front 14

Standard Deviation Range

Back 14

Measurement of "dispersion"; calculated by:

- subtracting the standard deviation value from the mean value to establish the lowest number in the range

- adding the SD value to the mean value to establish the highest number in the range

- established for qc material by the lab as method of setting acceptable qc limits. Frequently 1, 2, and 3 SD are established

Front 15

Coefficient of Variation

Back 15

- useful when comparing two or more groups of data to determine which has the greatest precision

- the lower the coefficient of variation is for a group of data, the more precise the data

Front 16

QC Material

Back 16

- material that is analyzed along with the patient specimens and should be treated the same as patient specimens

- should be of the same matrix as the patient sample

Front 17

QC Material (Matrix)

Back 17

- the chemical and physical characteristics of the material that contains the analytes to be measured

- components of a sample other than the analytes of interest

Front 18

QC Analysis - Are results reported if QC is outside of the acceptable limit esablished by the lab? Should you still report if the method is out of control

Back 18

- if the qc result is outside of the acceptable limit established by the lab, the patient results should not be reported until the problem is solved

- no patient results should be reported until the method is "in control."

Front 19

Errors that cause a method to be out of control

Back 19

- Out of control means a result outside of established QC range

Two main reasons why a method is out of control

- Random error occurs solely by chance. Related to the precision of the method. More complicated method, more chances of random error

- Systematic error. All samples affected. May produce a "bias" in the method. related to the accuracy of the method. Instrument problem

Front 20

Measures of Precision

Back 20

- Variance

- Standard Deviation

Front 21

Levey-Jennings Chart

Back 21

- To analyze each qc value, plot the value on a Levey-Jennings chart

Front 22

CLIA'88 and good lab practices require how many QC's before patient results are reported

Back 22

- require at least 2 QC materials/day for each nonwaived method

Front 23

Shifts

Back 23

- occurs when QC results are all distributed on side of the mean for 5 to 7 consecutive days

- occurs because of systematic error

- cause must be found and corrected because the method is "out of control"

- a shift can be positive or negative

Front 24

Trends

Back 24

- occurs when QC results either decrease or increase consistently over a period of 5 to 7 days

- is due to systematic error

- trends occur more slowly

- cause must be found and corrected

- a trend can either be positive or negative

Front 25

What error causes shifts and trends?

Back 25

- Systematic error

Front 26

Westgard Multirules

(1 two s Rule)

Back 26

- rule is violated if either of the 2 controls exceeds 2 SD from the mean in either a positive or negative direction

- when this rule is violated, the other rules are applied

- if the qc results do not violate any other rule, even if one of the 2 results violates the 1 two s rule, the control results are accepted

Front 27

Westgard Multirules

(1 three s rule)

Back 27

- violated when the result is one of the 2 qc results is outside of 3 SD

- if a result is outside of 3 SD, less than 1% chance that the result is an accurate result. 99.7% chance the result is an outlier

- when either of the QC results violates this rule, the result is rejected. run is out of control and should not be accepted.

- usually due to random error.

Front 28

Westgard Multirules

(2 two s rule)

Back 28

- can be violated in 2 ways

- if both control results are >2 SD or <2 SD from the mean

- if one of the control results also exceeded 2 SD in the same manner in the previous run

- does not violate the 1 three s rule

Front 29

Westgard Multirules

(R four s rule)

Back 29

- violated when the difference, or range, between the 2 control values within a run is >4 SD

- violated when both control values violate the 1 two s rule but in opposite directions. one control is elevated higher than the +2 SD limit and the other is less than -2 SD limit.

- usually violated due to random error

Front 30

Westgard Multirules

(4 one s rule)

Back 30

- Can be violated in two ways. one level of control: 4 consecutive results fall on the same side of the mean and exceed plus or minus 1 SD of the mean. two levels of control: when both levels of control for 2 runs in a row exceed plus or minus 1 SD from the mean

- somewhat like the rule for a shift. the 4 results are on the same side of the mean (which is statistically unlikely) and exceed 1SD (but not 2SD).

Front 31

Westgard Multirules

(10 x Rule)

Back 31

- Can be violated in 2 ways. in 10 consecutive runs for one level of qc, the results are all on the same side of the mean. the 10 results can fall in either a positive or negative direction.

- when the results are all on the same side of the mean for both levels of control for 5 days (or 5 runs) in a row.

Front 32

Preventive Maintenance

Back 32

- instrument component maintenance

- corrective maintenance

- wide range of components needing maintenance

- Maintenance schedule prevents breakdown

- maintenance program prescribed by manufacturer and supported by agreement depending on instrument complexity

Front 33

Maintenance vs Repair

Back 33

- keep components in OEM (original equipment manufacturer) condition

- prevent failure

- perform maintenance procedures correctly as set forth by the manufacturer

- maintain physical integrity in as new condition

- Daily-Weekly-Monthly and as needed

- keep records of functions by date and person performing function

Front 34

Pm (Preventative Maintenance) and its impact on QC

Back 34

- proper function and performance

- owner/operator functions

- maker functions

- operator training

- alignments

- adjustments and mfg. specs

- proper replacement procedure

Front 35

Manufacturer Service Contracts

Back 35

- complex instruments must have Mfg. (manufacturer) support

- 24 hour availability to service

- lab operation and ability to provide critical service

- regulatory considerations

- documentation of due care

Front 36

PM program

Back 36

- functions

- schedules

- documents

- required by regulatory agencies

- ongoing process

- required commitment of time and money

- performance is planned and scheduled event that is a documented part of work

Front 37

Phases of Patient Care

Back 37

- pre analytical is everything that occurs with patient prior to actual analysis of sample

- analytical is process where specimens are being analysed

- post analytical is what the doctor does with the data produced

Front 38

Customer Expectations

Back 38

- who is the customer?

- health care provider is the customer's agent

- provider/doctor/practitioner are employees of the patient

- providers employs other sub providers

- courtesy, respect, and expectation of good outcome

- top quality in process

- competency expected and required

Front 39

Provider Expectations

Back 39

- accuracy

- complete order filled to their satisfaction

- happy patient with a favorable outcome

- results is a clinically relevant time frame

- speed and accuracy

Front 40

Corporate Expectations

Back 40

- profit

- cost

- shareholders

- stock price

- low overhead

- no bad publicity

Front 41

Expectations

Back 41

- different from each point of view

- a happy patient that got better

- condition improved

Front 42

Care Delivery System

Back 42

- accessing and acquiring of information/communication

- diagnostic data development and accumulation through imaging, lab and other vehicles

- planning or development of care plan based on accumulated data

- treatment or the implementation of care plan

- evaluation of process for improvement (QA)