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Introduction and Background
Purpose
This document provides guidance on quality assurance (QA) practices for
sites using or planning to use rapid test kits to detect antibodies to the
human immunodeficiency virus (HIV) waived under the Clinical Laboratory
Improvement Amendments of 1988 (CLIA) regulations.
Definition: waived rapid HIV tests
Waived rapid HIV tests are test devices or kits cleared by the U.S. Food and
Drug Administration (FDA) that are determined to meet the criteria for
waiver under CLIA.1 They are simple, single-use, disposable
devices, using minimal reagents, that can provide results in less than 60
minutes and are designed for use with unprocessed specimens (whole blood or
oral fluid specimens). Rapid HIV tests, when used with specimens that
require processing, such as plasma or serum, are not waived under CLIA.
How rapid HIV tests are used
Rapid HIV tests are used as screening tests to detect antibodies to HIV as
part of multi-test algorithms to aid in the diagnosis of infection with HIV.
Positive (reactive) rapid HIV test results are preliminary and must be
followed up with an approved confirmatory test.
Importance of a QA program
Although waived rapid HIV antibody tests are simple to use and can provide
reliable results when the manufacturer’s directions are followed, mistakes
can occur at any point in the testing process. To reduce mistakes and to
ensure that the FDA restrictions for sale of these tests are followed (see
Appendix A for information on the FDA sales restrictions), the testing site
must have a QA program in place before offering waived rapid HIV antibody
testing. The guidelines in this document outline the basic elements of a QA
program.
How to use these guidelines
These guidelines are intended to assist a range of providers in developing
policies, processes and procedures to ensure high quality HIV testing
services. The contents include a description of steps that should be taken
to identify and prevent errors in the testing process. Because rapid HIV
tests are used in many different settings, each site needs to decide how
best to fit the various QA elements into its own operation. For example, the
QA program in a large clinic or hospital where on-site laboratory support is
available may be quite different from an outreach setting with fewer
personnel and resources.
How this document is organized
This document and its appendices provide basic information that personnel
who offer waived rapid HIV testing should know. It includes information on:
- Basic elements of a QA program
- An overview of government rules that apply to using waived rapid HIV
tests.
- Examples of forms and checklists that can be used to record and
monitor QA processes and procedures.
Basic Elements of a Quality Assurance
Program
What is quality assurance?
Quality assurance (QA) refers to planned, step-by-step activities that let
one know that testing is being carried out correctly, results are accurate,
and mistakes are found and corrected to avoid adverse outcomes. Quality
assurance is an ongoing set of activities that help to ensure that the test
results provided are as accurate and reliable as possible for all persons
being tested. These activities should be in place during the entire testing
process, from the time a person agrees to be tested until after the test
results are provided.
How does quality assurance differ from quality control?
As described above, QA is an overall program of activities throughout
the entire testing process. Quality control (QC) is one part of the QA
program. Here are definitions for both terms2:
Term |
Definition
and activities performed |
Quality assurance |
Planned and organized activities to help ensure that
certain requirements for quality will be met. |
Quality control |
Operational techniques or tasks that are in place to find
and correct problems that might occur. |
Basic elements of a QA program for rapid HIV testing
Even though waived tests are simple to use, things can go wrong. To help
find and prevent problems, the basic elements of a QA program should be in
place before offering testing. More detail on these six elements is provided
in this document. These basic elements are the building blocks of a QA
program and are listed below.
- Organization of the QA program
- Testing personnel
- Process control
- Before testing
- During testing
- After testing
- External assessment
- Documents and records
- QA evaluation and troubleshooting
Organization of the QA program
Establishing a QA program
A QA program, no matter how simple, requires resources.3
Someone must oversee the program and ensure the necessary personnel and
supplies are available. Each organization must:
- Identify the person(s) responsible for managing the QA program
(this could be a senior staff member, outside consultant or a
network of individuals who oversee different aspects of the QA
program).
- Verify the testing process.
- Write site-specific procedures (step-by-step instructions) and
make them available to all personnel involved in testing.
- Ensure personnel know how to perform each of the procedures.
- Create mechanisms for communication so that personnel are
informed about problems when they are identified.
- Have a CLIA Certificate of Waiver if performing only waived
rapid HIV antibody or other waived tests, or be included under an
organization with a CLIA exception for limited public health or
mobile testing. (See
Appendix A for more information on regulatory
requirements.)
- Develop and implement mechanisms to ensure the site meets all
applicable Federal, State, and other regulatory requirements,
including requirements for biohazard safety.
Verifying the testing process
Before offering the test to clients or patients, each site should make
sure (verify) that the testing process works as planned. Verifying the
process includes: ensuring that personnel have been trained and are able
(competent) to perform their assigned tasks, the test kits work as expected
(e.g., give accurate results for a referenced panel of nonreactive, weakly
reactive, and reactive specimens), and that logistics are in place for
providing confirmatory testing of preliminary positive test results and
handling biohazardous waste.
Providing written testing instructions
Testing personnel must follow instructions provided by the manufacturer.
It is strongly recommended that step-by-step, written instructions be
made available to all personnel performing testing. The test kit package
insert provides text that can be used as a procedure for steps in the
testing process listed below:
Procedure |
Describes how to... |
Pretest information |
provide required pretest information to test
subject. |
Materials and storage |
maintain sufficient supplies of unexpired test
and control kits and adhere to the manufacturer’s temperature
ranges for storage and testing areas. |
Test performance |
collect specimens, perform the test, interpret
and report test results, resolve problems (troubleshoot) before
reporting results. |
Quality control |
check performance of new test kit lots and
shipments, frequency of routine QC testing, and actions to take
if controls do not work. |
Recommended site-specific written procedures
Site-specific procedures describing other operations should be written
and available to help ensure personnel know how to perform additional QA
tasks:
Procedure |
Describes how to... |
Personnel training and competency |
train and assess competency of new employees;
periodic competency assessment of all testing personnel. |
Safety |
use gloves and other personal protective
equipment (PPE); safely dispose of biohazard waste, including
used lancets or other sharps used for blood collection. |
Reporting |
report results including confirmatory results,
if applicable. |
Confirmatory testing |
refer specimens or test subjects for
confirmatory testing; manage test results. |
Documentation |
keep records and timelines for review, retain
and destroy when outdated. |
Testing Personnel
Overview
Having qualified, trained personnel who perform and supervise rapid HIV
testing and the various activities in the QA program is one of the most
important factors for ensuring accurate and reliable results. Key aspects of
this element include:
- Qualifications
- Training
- Competency assessment (i.e., how well they are doing
their job)
Personnel qualifications
There are no Federal requirements for who can perform waived tests;
however, some States have specific requirements for testing personnel.
Beyond any regulatory requirements, it is recommended that certain qualities
be considered when selecting personnel to perform rapid HIV antibody
testing. The following list of desirable qualities is based on practical
considerations and expert opinion:
- Sincerity and commitment – A dedication to performing
testing accurately, according to defined procedures.
- Literacy – The ability to read instructions and record
results is critical.
- Organizational skills – The level of skill necessary will
depend on the number and complexity of tasks an individual performs
in the testing process. If test volume is high and the individual
performing testing is doing several tests or managing several other
tasks simultaneously, organizational skills can be critical.
- Decision-making skills – Testing personnel should be able
to interpret results and be able to recognize and handle problems
that might arise.
- Communication skills – If the person performing the test
also is the one who shares results or other information with the
person being tested, being able to communicate clearly is important.
Components of training
Training is crucial to ensuring quality testing.4 Assurance
that personnel who perform testing receive training information is
required to purchase rapid HIV test kits (see
Appendix A for the FDA
sales restrictions). Personnel should be fully trained on how to perform
their assigned tasks and responsibilities. Training should be documented
for each individual; using training checklists is one way to handle this
documentation (see
Appendix B for an example checklist). The key
components to include in a training program are:
- The importance of QA and the elements of the site’s QA program
- How testing is integrated into the overall program
- How to perform the test, including procedures performed before,
during, and after testing.
- The use and importance of blood and body fluid precautions and
biohazard safety. (See Biohazard Safety/Universal or Standard
Precautions.)
Training method
A training method should optimally include the following activities:
- Read the instructions for performing the test.
- Watch someone perform the test or view a video of someone
performing the test.
- Practice performing the test with positive and negative control
materials.
- Practice performing the venipuncture, finger-stick and/or oral
fluid collection procedure.
- Review the procedures and forms on how to document testing.
Competency assessment
Before a trainee is permitted to perform testing alone for the first time,
his or her ability to conduct the test should be demonstrated and
documented. This assessment should also be carried out at periodic intervals
after training, such as every six months or other interval as determined by
the testing site. Competency assessment can be carried out in many ways, but
regardless of the method, every task for which an individual is responsible
should be evaluated. A supervisor or trainer should perform the assessment,
using a combination of methods to determine competency. Examples of these
methods are presented below.
Assessing performance of tasks done before testing
To assess task performance before testing, personnel should be observed as
they:
- Check and record the temperatures of the testing and
storage areas.
- Set up the testing area, label the test device and prepare
control and test results log sheets.
- Run the external controls and record results.
Assessing performance of tasks done during testing
To assess personnel’s ability to perform the test and interpret results:
- Observe personnel performing specimen collection and handling
according to the manufacturer’s instructions.
- Observe how the test is performed on a client/patient. If such
observation will interfere with the actual client-provider interactions,
observe test performance on a volunteer.
- Evaluate the use of Universal or Standard Precautions and procedures
for biohazard and sharps (e.g., lancets, needles) waste disposal.
- Review results obtained from testing a panel of referenced specimens
that show a range of results, such as five specimens that include
nonreactive, weakly reactive, and reactive results. Control materials
supplied by the manufacturer may be used as a source of specimens in the
panel. In addition, specimens may be obtained from laboratories
performing confirmatory testing or from other commercial sources.
- Appraise the individual’s ability to interpret results. This might
include using previously used test devices or pictures of devices that
show nonreactive, weakly reactive, reactive, and invalid results.
Assessing performance of tasks done after testing
To assess task performance after testing:
- Review test records and quality control results for proper
documentation.
- Observe oral reporting of results to a test subject (if trainee’s
responsibility).
- If confirmatory test specimens are collected on-site, observe the
collection and handling of venous blood and/or oral fluid specimens for
referral. If the frequency of reactive rapid test results is low, the
trainee should be observed collecting blood and/or oral fluid from a
volunteer staff member and demonstrate how it is processed for
confirmatory testing.
- Verify that confidentiality is maintained.
Process Control
What is process control?
Process control refers to the activities and techniques that are carried out
to ensure that the testing procedures are performed correctly, the
environment is suitable, and the test kit works as expected to produce
accurate and reliable results.
Steps in the testing process
Steps in the testing process follow the path of workflow beginning with
tasks before testing, followed by those conducted during and after testing.
This path of workflow and the associated steps are shown in the table below.
Detailed descriptions about each of the steps listed in this table are
provided in the remainder of this document.
Before testing
|
During testing
|
After testing |
- Check storage and room temperatures daily
- Check inventory and test kit lots, as needed
- Receive request for testing
- Provide HIV/AIDS test information to the test subject
- Set up test area, label test device
- Perform external QC according to the manufacture’s and the
site’s instructions
|
- Follow biohazard safety precautions
- Collect the blood or oral fluid specimen
- Perform the test
- Interpret the results
|
- Document results
- Report results to test subject
- Collect, process, and transport confirmatory test specimens or
refer clients/patients for follow-up
- Clean up and dispose of biohazardous waste
- Manage confirmatory test results
- Participate in periodic external quality assessment
|
Before Testing
Overview
As shown in the table above, there are a number of steps that must be
followed before testing a specimen. These activities are in place to
ensure that the conditions at which the test kits and controls are
stored and tests are performed are suitable, the test area and the test
subject are prepared, and the test is working appropriately.
Temperature control: test kits and control kits
Test kits and controls must be stored within the temperature ranges
specified by the manufacturer. These ranges vary with different test
kits. Place thermometers in refrigerators and monitor areas where kits
are stored. Check and record temperatures of the storage area on a log
sheet each day testing is performed. An example temperature log is
provided in
Appendix C.
NOTE: “Min-Max” thermometers maintain a record of the highest and
lowest temperature recorded during the observation period and can be
very helpful to monitor storage conditions.
When temperatures are out of range
If the temperature falls outside of the specified range, take action as
needed to adjust the temperature. If there are doubts about the testing
area temperature or whether test kits have stayed within the appropriate
temperature range, run external controls as described in the QC section
below to ensure test devices are usable.
Inventory control
Procedures should be in place to ensure adequate supplies of unexpired
test kits, controls, and other materials and should include:
- Rotating inventory to ensure the oldest kits are used first.
- Adhering to shelf life limitations defined by the manufacturer.
- Test or control kits should never be used beyond their
expiration dates.
- Discard any test kits that are past their expiration date.
- Once control vials are opened, their shelf life is reduced.
It is helpful to record on the control vial the date it is
opened and the date after which the opened control expires.
NOTE: It is useful to document on a log sheet when test and control
kits are received, their lot numbers and their expiration dates. (See
Appendix D for an example log sheet of control results.)
Setting up the testing area
The testing area should be prepared according to the specific site
procedure, which should include directions for:
- Setting up the workspace and organizing supplies,
- Ensuring lighting is adequate to interpret rapid HIV test
results.
As a rule of thumb, lighting is sufficient if standard newsprint
held next to the test device can be read without difficulty. (See
page 12 for additional information on interpreting results.),
- Preparing the test kit components and controls,
- Completing report forms.
NOTE: If test kits are refrigerated, test devices, other kit
components, and controls should be brought to room temperature before
opening and performing the test, according to the manufacturer’s
instructions.
Specimen identification and labeling the test device
It is critical to correctly identify each person to be tested and to
ensure that proper identification of the specimen is maintained throughout
the testing process.
Labeling is especially important when more than one test is being
performed at the same time. Using preprinted labels improves the
efficiency of performing this task. Label components of the test (e.g.,
vials of developer solution, test device, and test result logs) with the
name or identifying number of the person being tested before collecting
the specimen.
Providing information to test subjects
Manufacturers of rapid HIV tests provide a subject information pamphlet that
must be given to each person prior to performing the HIV rapid test, in
accordance with FDA sales restrictions. Each site may provide additional
information. For further details, see the CDC website, and
applicable State or local rules.
Quality control
Waived rapid HIV tests include two types of QC. These are described in the
table below.
Type of quality control |
Description of
activity |
Internal Controls |
Controls built into each testing device can verify the specimen was
adequate and the solution flowed through the device as intended.
Functions of internal controls vary by device. |
External Controls |
Known reactive and nonreactive liquid samples (controls) are either
provided in each test kit or purchased separately from the
manufacturer. External controls are surrogate samples used to
evaluate the integrity of the test system and whether the person
conducting the test performs it correctly. |
External quality control
How often controls are run will depend on the number of tests performed by
the site, how often new test kit shipments or lot numbers are received,
changes in storage and testing area temperatures, and turnover of testing
personnel. Sites testing large numbers of persons, and especially those
offering anonymous testing, should plan to run controls more often than
facilities conducting fewer tests. Each site needs to decide how often to
run controls based on its own situation and testing practices. Control
results should be documented. (See
Appendix D for an example of a log for
results of control testing.)
Incorrect control results
When external controls give incorrect results, none of the tests that were
run since the last time control results were correct can be considered valid
until troubleshooting is done to determine the source of the problem. If
test kits are determined to be faulty, everyone who was tested since the
last time control results were correct may need to be called back and
retested (unless a confirmatory test was ordered). Results of client
retesting should be documented along with steps taken to resolve problems.
Incorrect control results: troubleshooting
If external controls do not give the correct result, steps should be taken
to determine the source of error by following the external control kit
troubleshooting instructions. Troubleshooting steps help determine if the
source of error is the test kit, the external controls, or operator
technique. When necessary, contact the manufacturer for assistance and/or to
report defective test system components. Document steps take to resolve the
problem.
During Testing
Overview
This phase of the testing process involves running the test and interpreting
the results. Activities during testing include collecting the specimen,
performing the test, interpreting the internal control and client/patient
test results, and following biohazard safety guidelines.
Collecting the specimen
Follow the written procedure for whole blood or oral fluid specimen
collection, labeling, and handling. Further information on collecting blood
by skin puncture can be found in
Procedures and Devices for the collection of Diagnostic Capillary Blood
Specimens; Approved Standard – Fifth Edition.5
Performing the test and interpreting results
Follow the manufacturer’s step-by-step instructions for performing the test
and interpreting the results. Interpreting rapid HIV tests requires good
eyesight and adequate lighting. The test should be read from a comfortable
distance without manipulating the test device. If supplemental lighting,
such as a flashlight, is necessary, care should be taken to avoid shadows or
reflections that might lead to an incorrect interpretation of the test. (A
flashlight should never be used to shine light through the test device to
accentuate the test result.) Test results can be one of the following:
- Nonreactive (report as negative)
- Reactive (report as preliminary positive)
- Invalid (the test result is inconclusive and
cannot be interpreted)
Internal controls
Each rapid test device includes a built-in (internal) control. Internal
controls in test devices vary among test manufacturers, therefore, it is
important to read and understand the manufacturer’s explanation of the
location and functioning of internal controls for the test being used.
Evaluating internal control results
Internal control results are evaluated with every test. If the internal
control does not produce the expected result, the test result for the
client/patient is invalid, cannot be reported, and the test must be
repeated. If a second invalid result occurs, external controls should be
evaluated as described below before repeating the test a third time.
Running external controls to troubleshoot invalid or suspicious
results
If repeatedly invalid test results or an unexpectedly high number of
reactive results are obtained during testing sessions, external controls
should be run to help find out if problems are due to faulty test kits,
improper testing procedures, or something to do with the patient specimen.
It is important to run the positive and negative controls whenever two
consecutive invalid test results are obtained on a person being tested. If
the external control results are valid, the problem may be due to
interfering substances in the client’s/patient’s specimen.
Biohazard safety/ Universal or Standard precautions
All specimens and materials contacting specimens must be handled as if they
are capable of transmitting an infectious organism. As described in
Appendix
A, each site must ensure that the Occupational Safety and Health
Administration (OSHA) bloodborne pathogens standards are met. Persons doing
the testing must know how to safely handle potentially infectious specimens.
Also, according to Universal Precautions, all human blood and certain body
fluids should be treated as if know to be infectious for HIV, hepatitis B
virus, hepatitis C virus, and other bloodborne pathogens. Sites must have
available, and follow procedures for, biohazard safety to include
instructions for the use of gloves, hand washing, sharps and biohazardous
waste disposal, spill containment and disinfection. A different pair of
gloves should be worn for collecting a specimen from each person being
tested. Used gloves should be handled as biohazardous waste. For further
details on these precautions see the manufacturer’s package insert, OSHA
regulations and guidelines on Universal and Standard Precautions.2,6,7,8
After Testing
Overview
Quality assurance extends to those activities completed following the
performance of the test. Each site should have established procedures for:
- Reporting and recording results,
- Referring specimens (or test subjects, if specimens are not
collected on-site) for confirmatory testing,
- Managing confirmatory test results, and
- Conducting external quality assessment.
Reporting results
Reporting procedures should describe how results are provided to the person
being tested (verbal and/or written results) and how results are documented
in the person’s chart and in the test result logs. (See
Appendix E for an
example of a test result log.)
Referral for confirmatory testing
Whenever a rapid HIV test result is reactive (preliminary positive),
follow-up testing must be performed to confirm that the person being tested
is infected with HIV. Therefore, each site must have established procedures
for referral of either test specimens or persons being tested for
confirmatory testing when rapid test results are reactive. Collecting
confirmatory specimens on-site may improve follow-up, since some
clients/patients may not go elsewhere for the testing or to obtain results.
However, if the site is not able to collect confirmatory test specimens, a
procedure must be in place for referring clients/patients to another site to
obtain this testing.
NOTE: If the client/patient refuses confirmatory testing, this should
be documented in the test results log.
Confirmatory specimen and results handling
If specimens are collected on-site, the site must establish procedures
describing:
- How to collect, label, process, store, and document specimen transfer.
Note: It should be indicated on the referral laboratory test requisition
that the specimen is from an individual who has had a reactive rapid HIV
test result. (See
Appendix F for an example specimen transfer log.)
- Transportation of the confirmatory test specimens to the site(s)
where they will be tested.
- How confirmatory results are obtained to give to the client/patient.
- How to report confirmed positive HIV results to your state health
department, as required. Check with your State health department for
specific requirements.
Confirmatory testing protocols for a reactive rapid HIV test
For confirmatory testing of reactive (preliminary positive) rapid test
results, recommended testing algorithms are as follows:
- All reactive (preliminary positive) rapid test results must be
followed up with an approved supplemental test, such as a Western blot,
an immunofluorescent assay (IFA) or an RNA9,10 test, for confirmation.
- Confirmatory testing can be done on blood (plasma, serum, or dried
blood spots) or oral fluid specimens, though blood specimens have higher
accuracy than oral fluid specimens. Urine should not be used for
confirmatory testing because of its lower sensitivity.
Performing an enzyme immunoassay (EIA) screening test prior to a
confirmatory test is optional. Even if the EIA is nonreactive, the
specimen must proceed to confirmatory testing with a Western blot, IFA,
or RNA.
Follow-up testing for a negative confirmatory result
Most confirmatory test results will be positive; however, some may be
negative. A negative confirmatory test result indicates one of three
possibilities: specimen mix-up, early seroconversion (too early for antibody
detection by Western blot or IFA), or false positive rapid test result. If
the initial confirmatory test is negative, it is recommended that:
- For blood specimens, a repeat confirmatory test with a new blood
specimen should be done to rule out specimen mix-up or early infection.
- For oral fluid specimens, a repeat confirmatory test with a blood
specimen should be done because the Western Blot test is less accurate
with oral fluid than it is with blood.
Follow-up testing for an indeterminate confirmatory test result
Occasionally, confirmatory test results are indeterminate. If the Western
blot or IFA is indeterminate, it is recommended that:
- If the initial confirmatory test was conducted on blood, the person
should be advised to return for repeat confirmatory testing in one month
or a test for HIV RNA may be performed.
- If the initial confirmatory test was conducted on oral fluid, a
repeat confirmatory test (Western blot, IFA, or RNA) should be conducted
using a blood specimen.
See CDC’s Revised Guidelines for HIV Counseling, Testing and Referral
Handling confirmatory test result discrepancies
Procedures should describe how to handle result discrepancies when the rapid
test result was reactive and the confirmatory test was negative or
indeterminate. If the laboratory providing confirmatory testing performed an
EIA test only and reported a nonreactive or negative result, the testing
site should contact the confirmatory testing laboratory and request a
Western blot, IFA, or RNA test. If the original specimen is not available, a
new specimen will need to be collected to be used for confirmatory testing.
External assessment
Overview
External assessment, an evaluation of the testing process by an
impartial outside source, is a way to evaluate how well testing is being
performed and whether it is being performed reliably. It can help to
identify existing or potential problems. Moreover, information gathered
can provide an educational tool to improve performance. Although not
required by Federal (CLIA) regulations for waived testing sites, some
form of external assessment is highly recommended.
Methods for external assessment
Every reactive test is externally assessed by a second, confirmatory test.
However, if there is a low prevalence of HIV infection in the population
being tested, these assessments may be rare and will not provide an external
check for the majority of the results, i.e., those that are nonreactive.
Other ways to assess performance may be needed. Some external assessment
mechanisms include:
- Comparing the reactive results with the confirmatory test results.
- Arranging for someone outside the organization to observe testing.
- Participating in a proficiency testing (PT) or external performance
evaluation program. (For more information on these programs, see
Appendix G.)
Documents and Records
Overview
One of the hallmarks of an adequate QA program is comprehensive
documentation. Sites using waived rapid HIV tests should have policies and
procedures describing what QA records are required and how and when they are
reviewed, stored, and destroyed. Having a supervisor review records
periodically is recommended. State regulations or other governmental or
accrediting agencies may require facilities to have specific record
retention policies. QA records include the following:
Temperature logs
Temperature logs should include a daily record of the refrigerator and/or
room temperature where test kits and external controls are stored and the
temperature of the testing area. Thermometers should be placed in each
location. Laboratory grade thermometers, which can be purchased from medical
or laboratory supply houses, are recommended and their accuracy checked
periodically (e.g., every six months) by comparison with another
thermometer.
External control result logs
External control records should include the date and time of control
testing, lot number and expiration date of the test kit, lot number and
expiration date of the controls, control results, and corrective action
taken if control results are unacceptable. Control records should be kept in
the order in which they were completed so they can be easily compared with
the test records. This will help find answers if there are questions about
testing performed within a specific time frame.
Test result logs
Test result records should include the date and time of testing, an
identifier for the person being tested, a test kit lot number and expiration
date, test result, action taken if the result was invalid, identification of
the person who performed the test, whether confirmatory testing was
requested, including the type of specimen sent for confirmation (e.g., oral
fluid, blood), and the confirmatory test results when they are available. If
more than one person is conducting testing, there should be a mechanism to
chronologically link the test record log sheets to detect problems, such as
invalid results occurring repeatedly with the same test kit lot number.
QA Monitoring and Troubleshooting
Overview
Each site should have protocols to identify key QA measures that are
routinely monitored and evaluated and have corresponding troubleshooting
procedures to resolve problems that may occur. Significant problems,
especially those concerning the accuracy of the rapid HIV test in use should
be immediately reported to the QA manager or appropriate supervisory
personnel. The local or state HIV test coordinator and the manufacturer
should be notified when appropriate.
QA monitoring
QA managers should routinely monitor and evaluate QA measures. Some
suggested measures include the following:
- Number of tests or external control materials that expired before use
or occurrences of expired tests used for diagnostic or QC purposes
- Number of days tests or QC materials were stored or used outside of
temperature specifications
- Frequency of external QC testing compared with test site procedure
- Frequency of invalid or incorrect results for external control
testing or patient/client testing
- Proportion of negative and preliminary positive patient/client
results
- Proportion of reactive rapid test results confirmed positive of all
reactive rapid test results
Troubleshooting
Troubleshooting procedures should be available to all testing personnel and
include the following:
- When to discontinue testing, for example, when the external control
results are unacceptable as described in the package insert
- How to take corrective action, or an action taken in response to a
problem, such as contacting the manufacturer when the external control
results are unacceptable and following the advice provided
- How to document problems and actions taken, such as a logbook where
problems and corrective actions can be recorded
- How to verify the corrective actions taken addressed the problem
NOTE: In accordance with Federal regulations, manufacturers of
diagnostic devices must monitor, investigate, and report to the FDA
complaints about device performance.
Expired tests or QC materials
When tests or external controls expire before they can be used for
testing, QA managers should consider evaluating the following:
- Inventory management, ordering, and storage procedures, to
ensure materials have a reasonable shelf life
- The use of test and control materials
- If needed, adjust ordering procedures, revise QA protocols, or
retrain staff.
Tests or QC materials stored or used when temperatures are outside
of specifications
When tests or external controls are used or stored outside of the
manufacturer’s temperature specifications, QA managers should consider
the following actions:
- Determine the cause for out-of-range temperature(s) and ensure
corrective measures have been taken.
- Confirm whether tests were used in out-of-range temperatures, if
procedures were followed, and if testing personnel were aware of
temperature conditions.
- Determine whether external QC tests were performed to verify the
test could be performed and correctly interpreted.
- If needed, modify procedures and retrain staff on temperature
control specifications.
Excessive External QC tests
Because of the costs associated with rapid tests, QA managers should
monitor the ratio of tests used for diagnostic purposes to tests used
for external QC purposes. If the ratio is less than 20 patient/client
tests for each set (positive and negative) of external controls tested,
then the number of tests used for external QC may be excessive. (Twenty
tests is the smallest number of CLIA-waived rapid tests manufacturers
provide per kit.11-13) If external QC testing is excessive
because of the interval defined by the specific test site procedure
(e.g., daily), consider adjusting the frequency of QC testing (e.g.,
from daily to weekly, bi-weekly, or monthly) to a more appropriate
interval.
Incorrect or invalid QC test results
QA managers should consider the following procedures when incorrect or
invalid QC test results are observed:
- Evaluate procedures for testing external controls and review
records of control results.
- Perform troubleshooting procedures in accordance with the
manufacturer’s control kit instructions to determine the source of
the incorrect or invalid result.
- If test devices used with valid external control materials
provide invalid or incorrect results, discontinue testing and
contact the manufacturer.
- Resume testing only after tests on external control materials
provide correct results and document corrective actions.
- If needed, modify the QA protocol and/or retrain staff on
appropriate testing of external controls.
Invalid patient/client test results
QA managers should consider the following actions when excessive invalid
client test results are observed:
- If possible, observe specimen collection, testing, and result
interpretation to confirm test procedures are performed correctly.
- Confirm the test device(s) used had not expired.
- Review documentation of testing to ensure procedures are being
followed.
- Determine whether external controls were tested after the second
invalid test result and if troubleshooting procedures were followed.
If not, perform external QC testing using test devices from the same
kit or lot to determine proper functioning of the test device.
- Perform troubleshooting procedures according to the manufacturer’s
instructions.
- If test results using valid external control materials provide
invalid results, testing should be discontinued.
- If the test kit/lot is determined to be faulty, notify the
manufacturer.
- Resume testing only after tests on external controls provide
correct results and document corrective actions.
- If needed, retrain staff on appropriate testing procedures.
- If appropriate, notify local or state health department HIV test
manager.
Excessive false-positive patient/client test results
QA managers should periodically compare the total number of reactive
rapid test results with the number of confirmed positive results. If the
resulting ratio of false-positive rapid test results suggests the test
is not performing according to the manufacturer’s specifications (refer
to the product insert for population prevalence and performance data),
QA managers should consider the following actions:
- Evaluate the expiration dates of test kits and temperatures of
the storage and testing areas for test kit lots that produced, and
did not produce, false positive test results.
- Review records of external control testing for test devices of the
same lot and subjected to the same temperature conditions.
- Perform additional troubleshooting procedures in accordance with
the manufacturer’s instructions.
- Evaluate facility testing procedures and, if appropriate, modify
the QA protocol and/or retrain staff on appropriate testing
procedures.
- If necessary, inform the manufacturer and appropriate local or
state health department HIV test managers. If appropriate, consider
discontinuation of testing or changing to another waived test
vendor.
References
- Clinical Laboratory Improvement Amendments of 1988, 42 U.S.C. 263a
PL100-578 (1988).
- CLSI document HS1-A2. A quality system model for health care;
Approved guideline – Second edition. CLSI, Wayne, PA, 2004.
- CDC.
Good Laboratory Practices for Waived Testing Sites. MMWR
Recommendations and Reports. 2005; RR-54:13.
- CLSI document GP21-A2.Training and competence assessment; Approved
guideline – Second edition. CLSI, Wayne, PA, 2004.
- CLSI document H4-A5. Procedures and devices for the collection of
diagnostic capillary blood specimens, Approved standard guideline. CLSI,
Wayne, PA, 2004.
- Occupational Safety and Health Administration
regulations, 29CFR Part 1910.
- CDC. Perspectives in disease prevention and health
promotion update: Universal precautions for prevention of transmission of
human immunodeficiency virus, hepatitis B virus, and other bloodborne
pathogens in Healthcare
settings. MMWR 1988; 37(24):377-88.
- Garner JS, Hospital Infection Control Practices
Advisory Committee. Guideline for isolation precautions in hospitals.
Infect Control Hosp Epidemiology 1996;17:53-80, and Am J Infect Control
1996;24:24-52.
- CDC.
CDC Revised Guidelines for HIV Counseling, Testing, and Referral.
MMWR Recommendations and Reports. 2001; RR-19:50.
- APTIMA® HIV-1 RNA Qualitative Assay package insert. Gen-Probe®, San
Diego, CA 92121, 2006.
- Uni-Gold™ Recombigen® HIV package insert. Trinity biotech USA, St.
Louis, MO 63114, 2004.
- OraQuick® ADVANCE Rapid HIV-1/2 Antibody Test package insert.
OraSure Technologies, Inc., Bethlehem, PA 18015, 2005.
- HIV-1/2 STAT-PAKTM Assay package insert. Chembio Diagnostic Systems,
Inc., Medford, NY 11763, 2006.
Glossary
AIDS: Acquired immunodeficiency syndrome, caused by the human immunodeficiency
virus (HIV),
can affect the immune and central nervous systems and can result in
neurological problems, opportunistic infections, or cancers.
CLIA-waived test: A test system, assay, or examination that has been cleared by the FDA
for home use, or has been determined by the FDA to meet the CLIA
criteria of being a simple test with an insignificant risk for an
erroneous result.
Confidentiality: Pertains to the disclosure of personal information in a relationship of
trust and with the expectation that it will not be divulged to others in
ways that are inconsistent with the original disclosure. Confidentiality
must be maintained for persons who are recommended and/or who receive
HIV counseling, testing, and referral (CTR) services.
Confirmatory test: A highly specific test designed to confirm the results of an earlier
(screening) test. For HIV testing, a Western blot, an immunofluorescence
assay (IFA), or an RNA is used as a confirmatory test. The person is
considered HIV-positive only if the confirmatory test result is
positive.
EIA: Enzyme immunoassay, sometimes referred to as ELISA, is a commonly used
screening test to detect antibodies to HIV.
False negative:
A negative test result for a person who is actually infected.
False positive: A positive test result for a person who is actually not infected.
HIV: Human immunodeficiency virus, which causes AIDS. Several types of HIV
exist, with HIV-1 being the most common in the United States.
Indeterminate test result:
A possible result for a Western blot, which might represent a recent HIV
infection or a false-positive.
Nucleic acid amplification testing:
A type of testing that identifies viral genes (e.g., specific sequences
of nucleic acids) using gene amplification technologies such as
polymerase chain reaction (PCR).
Preliminary positive test: For rapid HIV testing, a test
result that is reactive by a rapid HIV test and not yet confirmed
positive by a Western blot, IFA, or approved RNA supplemental test.
Rapid HIV test: A test to detect antibodies to HIV that can be collected
and processed within a short interval of time (e.g., approximately 10 to
60 minutes).
Referral laboratory: An external laboratory to which a sample is
submitted for a supplementary or confirmatory examination procedure and
report.
RNA test: A test used to detect HIV-1 in plasma using nucleic acid
amplification. The test may be used as a confirmatory test for a
reactive rapid HIV test result to aid in the diagnosis of infection with
the virus.
Screening test: An initial test, usually designed to be sensitive, to
identify all persons with a given condition or infection.
Seroconversion: Initial development of detectable antibodies specific to
a particular antigen; the change of a serologic test result from
negative to positive as a result of antibodies induced by the
introduction of antigens or microorganisms into the host.
Western blot: A laboratory test that detects specific antibodies to
components of a virus. Chiefly used to confirm HIV antibodies in
specimens found to be reactive using a screening test. |