QUALITY CONTROL AND ASSESSMENT

Effective Date: 
Tue, 05/01/2012
Reviewed: 
Mon, 03/03/2014
Policy: 

PURPOSE

To identify control materials used throughout the laboratory and to formulate a comprehensive plan to perform, monitor, evaluate and take corrective action with control values obtained. A comprehensive quality control plan allows laboratory personnel to record and monitor the daily performance of the analyzers and reagents used throughout the laboratory and to predict shifts and trends in control materials over a period of time.

Procedure: 

PROCEDURE FOR PERFORMANCE OF CONTROL MATERIAL

ABAXIS PICCOLO (CHEMISTRY)

1. Per Abaxis, run the normal and abnormal controls (Level 1 and 2) every 30 days. Additionally, the Piccolo has automatic on-board self-calibration, and contains an Integrated Intelligent Quality Control (IQC) that checks samples, reagents and analyzer with each run. The laboratory should check with their state office if state licensure is required and quality control requirements are more stringent.

2. It is also important to check QC in the following situations:

a. Whenever laboratory conditions have changed significantly

b. When training or re—training of personnel is indicated

c. When test results do not match patient symptoms or clinical findings

BECMAN COULTER Ac·t diff`2 (HEMATOLOGY)

1. At least two valid levels of quality control results must be obtained by running two of the three levels of the Coulter 4C-ES Low, Normal and High control at the beginning of each day of operation, prior to running patient samples and after any daily maintenance has been performed

 2. lt is also important to check QC in the following situations:

a. change in reagent lot number

b. calibration

c. service call or component replacement

d. selected maintenance procedures

e. unusual shifts or trends in patient results

URISYS 1100 (URINALYSIS)

1. Run a normal and abnormal control each day of patient testing.

2. Controls should also be run if results on strip do not match the clinical picture of the patient and verification of test strips must be made.

Waived Kit Testing:

1. In general, run a positive and negative control when a new kit or box of reagent is opened. Record the results on the proper log.

2. Always check the manufacturer insert for directions for External Quality Controls. Some manufacturers may have specific recommendations for performance of controls.

3. For Urine HCG, perform and document a positive and negative control for each opened kit. (Do this each day of use if an automated system is used) You may need to find suitable controls, since the manufacturer usually does not include them with the reagent kit. Options include:

• Ordering separate control material from the manufacturer. Consult the product insert for ordering information.

• Urinalysis controls are sometimes formulated to test for urine pregnancy. Consult the product insert to determine if there are HCG values.

• Aliquot and freeze small amounts of assayed patient urine. (Positive Z known pregnant female.) Negative = male) Date the aliquot tubes, discard after 1 year.

4. If controls do not perform as expected, repeat. Do not use the kit for patient testing if controls do not yield expected results.

5. Also, repeat controls when:

a. Improper handling or storage of the kit is suspected.

b. Patient results are unexpected.

c. A new operator is trained to use the kit.

GENERAL GUIDELINES FOR PERFORMANCE AND ACCEPTANCE OF QUALITY CONTROL

TWO CONTROL PROTOCOL

1. Accept the run if:

a. Both the controls read within +/- 2 SD of the established mean.

2. Reject the run if:

a. Any control is greater than 2 SD from the established mean.

3. If the run is rejected:

a. Rerun the controls. If they are still outside acceptable limits, make up fresh controls and rerun. If the controls are within limits, run and report patient results.

b. If after the rerun, the controls are still out of acceptable limits, check the following variables: expiration date of reagents, change in lot numbers of controls or reagents, date of last calibration, and maintenance procedures.

c. If control values are still unacceptable, troubleshoot according to the manufacturers guidelines.

d. If the situation persists, do not run patient samples. Send specimens to the appropriate reference laboratory, according to the patient’s insurance carrier stipulations.

e. When the situation is corrected and controls are again acceptable, patient testing may resume and results may be reported.

EQUIVALENT QUALITY CONTROL AND THE ABAXIS PICCOLO

The Abaxis Piccolo is a Chemistry test system that incorporates internal quality control mechanisms that monitor all potential sources of error throughout the testing process. The Piccolo self—calibrates with each patient run, utilizing the onboard, continuous intelligent Quality Control (iQC), which monitors the analyzer, reagent reactions and sample to ensure chemistry and instrument integrity. CLIA regulations provide an alternative to the requirement for two levels of external quality control testing to be performed each day of patient testing, when a test system meets certain · criteria and is eligible to perform one of three equivalent quality control options.

The Abaxis Piccolo utilizes Option 1 of the equivalent quality control requirement, With this option, the internal control mechanisms monitor ALL sources of error, and the laboratory must conduct a qualifying study by:

1. Perform internal QC each day for 10 consecutive testing days

2. Perform two levels of external quality control testing each day for ten consecutive testing days

3. Verify that all results for both internal and external quality control testing is acceptable throughout this ten day period

After completion of this study, with acceptable performance throughout the 10 day testing period, the laboratory may perform Abaxis Piccolo internal QC daily, with external quality control performance once per month.

If this monthly QC fails, and is not within range when repeated, or when proficiency testing fails or problems with the analyzer are identified, correct action must be taken to correct the problem. The laboratory should:

1. Troubleshoot the source of the problem

2. Correct identified sources of error·

3. Review all patients tested since the last performance of external quality control to identify if any patient results have been compromised

4. Notify physician of any patient testing which may need to be repeated

5. Complete an additional 10 day evaluation of both internal and external quality control before resuming monthly quality control testing Always document any corrective actions taken on the Corrective Action Log for follow-up review.

QUALITY CONTROL GRAPHS

A pictorial representation of quality control results, such as Levy-Jennings graphs, is a valuable tool for assessing control results. These graphs can illustrate a method’s accuracy and precision over time. Normally assayed material should show a random pattern clustering around an expected target point. Problems with the instrument, reagents, controls materials, and operators can be assessed by examining these graphs weekly to look for unexpected patterns.

SHIFTS AND TRENDS

A sudden change in direction, either up or down, of the values you are obtaining is called a shift. A common cause of this is changing to a new lot of reagents. As long as controls are still within range, you may continue to report outpatient results, but you should investigate the shift to eliminate the possibility of erroneous testing. You may need to recalibrate the analyte to resolve the shift in quality control values, but small shifts may be acceptable with the introduction of new lots of reagents.

A trend is when you observe five or more consecutive values which are progressively higher or lower than the stated mean. A number of factors can cause a trend, including deteriorating controls or reagent, instrument component failures, the need for instrument maintenance, drift in calibration, changes in standard lot number, or bacterial growth in your control material. Check to make sure there has been no change in reagent, control or standard lot numbers, beginning with the date the trend started. Proceed with the following steps:

• Try a new bottle of control

• Open or reconstitute new reagent

• Troubleshoot the instrument using the manufacturer’s guidelines or call the customer service representative

Again, as long as your control values are still within range, you may report outpatient results, but it is necessary to evaluate a trend to eliminate the possibility or reporting erroneous results.

When performing testing on the Abaxis Piccolo, it is not necessary to evaluate shifts and trends or Levy-Jennings charts when reviewing quality control, as quality control testing is performed only once per month, under normal testing circumstances. Follow the guidelines stated previously under "Equivalent Quality Control and the Abaxis Piccolo” for evaluation of quality control utilizing this option.

PROCEDURE FOR CHANGE IN LOT OF CONTROL MATERIAL

(when performing daily quality control testing)

"Assayed" controls have stated means and standard deviations in their product literature; however you should verify the established means and adjust them to your facility as necessary: ·

1. You may begin patient testing with the stated means and ranges, but you should gather at least 20 control points for each level in use.

2. The sum of these points divided by the number of samples run is your "actual mean" for that control.

3. Use this number to verify the "established mean" as stated in the manufacturer’s literature. If it is different, then adjust the mean and standard deviation to more closely reflect those established for the facility.

4. After 50 and 100 points are gathered, examine the resulting mean and Standard Deviation (SD) and make further small adjustments as necessary.

5. Once the laboratory’s mean and range is established it should then not be changed until the lot number of controls is changed. Any unexpected trends or shifts should be investigated as possible instrument, reagent, or control problems.

When "unassayed" control material is used, generally this means that the manufacturer has not established a mean for your instrument and/ or reagent. Therefore, a new mean and standard deviation will have to be determined each time a new lot of control material is to be put into use. This is should be done before existing control lots expire. You would also do this if a new brand of controls will be used, a new procedure is implemented or new equipment is acquired. It is important to perform this procedure in an adequate time frame, usually at least two weeks in advance of the change:

1. Identify the date for the change, preferably the first day of the month.

2. In the instrument QC program, input the manufacturer suggested mean and SD for each parameter if this information is available. If not, enter data for a method similar to the facility’s method.

3. Run the new control once a day, or in a morning and afternoon run.

4. Continue to run the old lot of control material as well, until sufficient data for the new lot of control has been established.

5. When at least 2O points of the new control material have been accumulated, determine the new mean and SD for each parameter.

6. When the old lot number of control material has been used up or is expired, the new one will be placed into use on the test system.

7. Once the new lot of control material is started, do not submit data from the old lot of QC to the evaluation or QAP program.

If for any reason, there is not enough time to perform the unassayed control procedure as established, use the following method:

1. Run the new control twice per day, in the morning and afternoon.

2. Obtain 10 points of data.

3. Use the mean from these points and the SD from the control insert sheet.

4. Review the data when 20 points are obtained to make adjustments as necessary.

DOCUMENTATION REQUIREMENTS FOR GRAPHS

Quality control graph records should be retained for a minimum of two years for all non-waived quantitative procedures. Electronic storage is acceptable, as long as the information can be accessed and as long as an electronic copy of the information is kept as a back-up. It is prudent to check this storage system periodically as a part of Quality Assessment.

Documentation of review of Quality Control Graphs, and/or individual quality control points is required. These graphs or points should be reviewed by the Laboratory Supervisor or designee at least monthly. Corrective actions can be documented directedly on the printouts. If review of electronic records is performed, this must be documented as well.

QAP PROGRAMS

Some control materials offer a QAP program. Monthly control data may be downloaded from the analyzer computer system and sent to the QAP company for a compilation of both individual data and peer group comparison.

This information should be reviewed monthly by the Laboratory Supervisor and corrective actions performed and documented as needed.

MANUAL QUALITY CONTROL DOCUMENTATION

For analyzers or testing that do not have on-board compilation of quality control data, either a log will be kept to document quality control values, or they may be placed on the worksheets, along with any tapes or reports from the analyzer to show testing of quality control material. Review of these should also be performed monthly and documented.