Definitions of the levels of evidence (I—III) and grades of the recommendation (A, B, C, I) are presented at the end of the "Major Recommendations" field.
Note from the National Academy of Clinical Biochemistry (NACB) and the National Guideline Clearinghouse (NGC): The Laboratory Medicine Practice Guidelines (LMPG) evidence-based practice for point-of-care testing sponsored by the NACB have been divided into individual summaries covering disease- and test-specific areas. In addition to the current summary, the following are available:
Bioterrorism
Are there tests for the detection of Bacillus anthracis spores as agents of bioterrorism that are or will be available for use as point-of-care testing (POCT)? Are these needed for "field" or POCT testing?
Guideline 109. No recommendation can be made for or against routinely providing POCT because there are no data to support the fact that routine nasal swabs in each office or laboratory would provide information that would aid in determining cause or presence of a bioterrorism agent, in particular anthrax. There is no good literature with randomized studies that would allow for one to determine if the need for testing these nasal swabs at POCT would aid in the investigation.
Strength/consensus of recommendation: I
Clostridium Difficile
Is there research available evaluating the clinical outcomes of rapid tests for C. difficile toxin performed at the point of care (POC)?
Guideline 110. There is fair evidence against POCT for C. difficile toxin at this time.
Strength/consensus of recommendation: C
Level of evidence: II
Infectious Mononucleosis (IM)
Have patient outcome studies been performed on the rapid tests that are available to screen for IM at the POCT site, and have the studies been performed by the POCT personnel?
Guideline 111. Recommend POCT for heterophile antibodies (HA) testing in patients >12 years old, fair evidence to support procedure. However, some individuals do not produce HA in IM, and if a negative test is obtained, Epstein-Barr virus (EBV)-specific serologies should be performed before ruling out IM.
Strength/consensus of recommendation: B
Level of evidence: II
Guideline 112. Recommend against POCT for HA testing in children <13 years old, fair evidence against procedure. It is well documented in the literature that a large portion of children do not produce HA. In these patients, EBV-specific serologies should be performed before ruling out IM.
Strength/consensus of recommendation: C
Level of evidence: II
Chlamydia Trachomatis and Neisseria Gonorrhoeae
Will direct examinations for C. trachomatis and N. gonorrhoeae, delivered as POC tests, achieve high enough sensitivity for routine care?
Guideline 113. POC Chlamydia tests should only be used while the patient is present for treatment and follow-up. If the results are not available until after the patient leaves, do not use POC tests. The gram stain may be used as a POC test for symptomatic men with urethral discharge.
Strength/consensus of recommendation: A
Level of evidence: II (small analytic studies and opinions of respected authorities)
Group A Streptococcal Antigen Tests
Are rapid tests for Group A streptococcal antigen performed at the POC useful for diagnosis of Group A streptococcal (GAS) infections? Is there research available evaluating the clinical outcomes of rapid tests for Group A streptococcal antigen performed at the POC?
Guideline 114. Rapid tests for diagnosis of GAS pharyngitis in general provide clinically useful, financially justified results; these tests also have utility for testing nonpharyngeal specimens. The recommendation of the American Academy of Pediatrics to confirm negative rapid GAS antigen detection results of pharyngeal specimens from children should be followed; the Infectious Diseases Society of America recommendation to perform laboratory tests (either throat culture or rapid antigen detection) on specimens from adults with clinical evidence of pharyngitis should be followed.
Strength/consensus of recommendation: A
Level of evidence: III
Group B Streptococci
Is there research available evaluating the clinical outcomes of rapid tests for group B streptococcus? Are rapid test kits reliable, and should they or should they not be used for POCT?
Guideline 115. There is insufficient evidence to recommend POCT for group B streptococcus. There was no literature found demonstrating a link to POC testing for Group B streptococcus and outcomes data.
Strength/consensus of recommendation: I
Helicobacter Pylori
Is there research available evaluating the clinical outcomes of rapid tests for H. pylori at the POC?
Guideline 116. There appear to be tests available for sensitive and specific testing at POC for H. pylori, but as yet no studies have been done to determine whether such POCT would have favorable clinical outcomes. Because tests including stool antigen tests, and urea breath tests have proven comparable in overall detection of H. pylori at the POC, studies should be conducted to determine their utility in early detection and treatment of dyspepsia-associated H. pylori disease.
Strength/consensus of recommendation: I
Influenza Virus Infection
Are there studies available for evaluating the clinical outcomes of rapid tests for influenza virus performed at the POC?
Guideline 117. The guideline developers found that the literature supports the lack of sensitivity and accuracy of clinical criteria alone for the diagnosis of influenza virus infection. Therefore, additional testing, including POCT, may be useful. These tests should only be used for POCT when the virus is prevalent in the community, and negative results should not be used to rule out influenza virus infections. Only nasopharyngeal swabs, aspirates, or washings should be used with these assays. The sensitivities of the tests using throat swabs are 60% or less. During the peak of an outbreak, not every single patient with flu symptoms needs to be tested, unless a positive result will result in the withholding of antibiotics. The greatest cost benefit is achieved when unnecessary antibiotics are not prescribed for patients with positive influenza virus test results. If treating with antivirals is being considered, the patient must be treated within the first 48 hours of onset of symptoms for even a minimal effect to be achieved.
Strength/consensus of recommendation: B
Level of evidence: I and III
Respiratory Syncytial Virus (RSV)
Are there studies available for evaluating the clinical outcomes of rapid tests for RSV performed at the POC?
Guideline 118. The literature supports the lack of sensitivity and accuracy of clinical criteria alone for the diagnosis of RSV infection; therefore, additional testing, including POCT, may be useful when used appropriately. Tests for RSV suitable for POCT have a broad range of sensitivity and specificity, and their positive and negative predictive values vary greatly, depending on the prevalence of the virus in the community. Because of these performance characteristics, these tests should only be used for POCT when the virus is prevalent in the community, and negative results should not be used to rule out RSV infections. Only nasopharyngeal swabs, aspirates, or washings should be used with these assays. The sensitivities of the tests using throat swabs are 60% or less. The greatest cost benefit is achieved when unnecessary antibiotics are not prescribed for patients with positive RSV test results.
Strength/consensus of recommendation: B
Level of evidence: I and III
Human Immunodeficiency Virus (HIV) Testing
Do rapid HIV antibody tests perform as well as laboratory-based methods (a) in validation studies and (b) in field studies? Are there sources of analytic variation unique to rapid/POC HIV test kits?
Guideline 119. Under validation conditions, currently available HIV antibody tests perform with comparable sensitivity and specificity to laboratory-based enzyme-linked immunosorbent assay (ELISA) methods in patient populations that are suitable for rapid testing.
Strength/consensus of recommendation: B
Level of evidence: I (at least 1 randomized controlled trial)
Guideline 120. In field studies, currently available HIV antibody tests perform with comparable sensitivity and specificity to laboratory-based ELISA methods.
Strength/consensus of recommendation: B
Level of evidence: I (at least 1 randomized controlled trial)
Guideline 121. Rapid/POC tests for HIV should be used by personnel well trained in the method, with ongoing quality control and performance-improvement programs.
Strength/consensus of recommendation: A
Level of evidence: II and III (small studies and opinions of respected authorities)
Guideline 122. Rapid/POC tests should be used with caution, if at all, to follow exposed persons who are heavily antiretroviral therapy (ART) treated.
Strength/consensus of recommendation: B
Level of evidence: II (dramatic results in uncontrolled experiments)
Does HIV testing at POC improve rates and timing of antiretroviral therapy (ART) for HIV-infected women in labor?
Guideline 123. Rapid HIV testing in the peripartum period, laboratory-based or POC, improves antiretroviral prophylaxis and most likely reduces peripartum transmission of HIV, provided systems are in place to use the information therapeutically.
Strength/consensus of recommendation: A
Level of evidence: II
Does HIV testing at POC provide benefits for blood- and body-fluid-exposed employees?
Guideline 124. Strongly recommend rapid testing of the source-patient for employee exposures.
Strength/consensus of recommendation: A
Level of evidence: II
Guideline 125. No recommendation regarding testing at POC.
Strength/consensus of recommendation: I
Does HIV testing at POC improve HIV case finding, entry into comprehensive HIV care programs, or facilitate changes in risky behaviors?
Guideline 126. No strong recommendation for rapid/POC testing in outreach settings can be supported by current literature, but there is reason to expect that certain populations could be better served by POC screening.
Strength/consensus of recommendation: I
Level of evidence: II
What algorithms for confirmatory testing should be used with POC HIV tests?
Guideline 127. Confirmatory testing should go directly to Western blot/immunofluorescence assay (IFA), bypassing a second enzyme immunoassay (EIA) step.
Strength/consensus of recommendation: A
Level of evidence: III
Guideline 128. In some resource-limited settings, a second, different rapid test is used for confirmation; this has not been carefully studied but is promising.
Strength/consensus of recommendation: I
Level of evidence: III
Trichomonas Vaginalis Vaginitis
Is there a clinical need for POC testing for the presence of T. vaginalis in the diagnosis of vaginitis? Will direct examinations for agents of vaginitis, delivered in POC format, achieve high enough sensitivity for routine care?
Guideline 129. The guideline developers would recommend POCT, given the fair evidence to support the procedure. Wet-mount examination of vaginal discharge for the presence of T. vaginalis is an insensitive procedure and should be replaced with newer methods that provide a higher level of sensitivity. Newer methods have been developed for POC that may result in better outcomes. Additionally, outcome data will need to be based on more sensitive tests that are used in pregnancy to establish an association with preterm labor/delivery and low-birth-weight deliveries.
Strength/consensus of recommendation: B
Level of evidence: III
Candida Vulvovaginitis
Are there POC tests that are available for the detection of yeasts in vaginal samples as cause of vaginitis, and are these tests necessary for good patient outcomes?
Guideline 130. No recommendation for or against the need for a POC test for the detection of yeast in a vaginal specimen. This is because there are no good studies that provide information that a rapid test for the diagnosis that is more sensitive than the wet-mount tests presently available would provide a better clinical outcome than what is presently obtained.
Strength/consensus of recommendation: I
Level of evidence: III
Bacterial Vaginosis (BV)
How accurate is the diagnosis of BV using clinical criteria alone or with a wet-mount observation?
Guideline 131. The guideline developers would suggest that the literature supports the lack of sensitivity and accuracy of clinical criteria alone for the diagnosis of BV. Therefore, additional testing, including POCT, may be necessary to investigate in the future.
Strength/consensus of recommendation: B
Level of evidence: II
What is the association of BV with complications of pregnancy, such as preterm birth?
Guideline 132. The guideline developers would recommend that clinicians routinely provide POCT for pregnant patients for the rapid diagnosis of BV because of its association with preterm birth.
Strength/consensus of recommendation: B
Level of evidence: II
Can a POCT that involves no wet-mount observation be used to detect BV?
Guideline 133. It would be of benefit to have other assays available that do not rely on direct wet mount or gram stain evaluations of vaginal discharge. These would potentially provide assays that could be used as POCT, especially in the pregnant woman. Some literature is available to support the use of non–wet-mount examination tests to make a laboratory diagnosis of BV. However, there are no outcomes studies using any assays other than direct observational examination tests such as wet mounts or gram stains.
Strength/consensus of recommendation: I
Definitions:
Levels of Evidence
- Evidence includes consistent results from well-designed, well-conducted studies in representative populations.
- Evidence is sufficient to determine effects, but the strength of the evidence is limited by the number, quality, or consistency of the individual studies; generalizability to routine practice; or indirect nature of the evidence.
- Evidence is insufficient to assess the effects on health outcomes because of limited number or power of studies, important flaws in their design or conduct, gaps in the chain of evidence, or lack of information.
Strength of Recommendations
A - The National Academy of Clinical Biochemistry (NACB) strongly recommends adoption; there is good evidence that it improves important health outcomes and concludes that benefits substantially outweigh harms.
B - The NACB recommends adoption; there is at least fair evidence that it improves important health outcomes and concludes that benefits outweigh harms.
C - The NACB recommends against adoption; there is evidence that it is ineffective or that harms outweigh benefits.
I - The NACB concludes that the evidence is insufficient to make recommendations; evidence that it is effective is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.
