Pathology/Lab Coding Alert

Coding for streptococcal detection methods can be confusing, with multiple references scattered through CPTs immunology and microbiology sections. The deletion of 86588 (streptococcus, screen, direct) in CPT Codes 2000 seems to have added to the confusion for some. But with a better understanding of the reasons for the different tests and the methods involved in conducting them, correct coding for streptococcus detection can enhance both compliance and reimbursement.

Code 86588, which many labs were using to report rapid strep screens, was deleted in CPT 2000 to end duplicate reporting with the other strep detection processes. To report the deleted code, according to CPT direction, see 86403,87081, 87430, or 87880.

86403particle agglutination; screen, each antibody

87081culture, bacterial, screening only, for single
organisms

87430 infectious agent antigen detection by
enzyme immunoassay technique, qualitative or
semiquantitative, multiple step method; streptococcus
group A

87880infectious agent detection by immunoassay
with direct optical observation; streptococcus,
group A

The reference to the different codes means that strep screening should be coded according to the methodology of the specific test being used, states Stan Werner, MT (ASCP) administrative director and corporate compliance officer of Peterson Clinical Laboratory in Manhattan, Kan. Theres a wide range of lab methods to detect streptococcal infections, including antibody or antigen screens using particle agglutination, culturing, enzyme immunoassay (EIA), or direct optical observation.

Rapid Strep Screens

Most rapid strep screens will be reported using code 87880, Werner advises. This concurs with Health Care Financing Administration (HCFA) program memorandum AB-99-84, which states: Effective for 2000, deletion of CPT code 86588 should be replaced with the use of code 87880. There are many different commercial tests on the market that would be coded 87880, says Werner. These tests may use different methods of EIA, but their common feature is that the endpoint is some type of visual result, such as a specific color change. This direct optical observation indicates the presence or absence of the streptococcus group A organism.

The rapid strep screens are common, easy-to-perform tests, states Mary Jo Bonifas, MT (ASCP), laboratory manager at United Clinical Laboratories in Dubuque, Iowa. One of these quick, visual detection methods typically is used at a physician office lab to determine if a sore throat is due to a streptococcal group A infection.

In fact, many of the rapid strep tests are approved for laboratories that are granted waived status under the Clinical Laboratory Improvement Amendments (CLIA) standards. A lab that is granted waived status is not required to meet the more rigorous standards of labs that perform tests of moderate or high complexity. As such, these labs are limited to tests that are simple to perform, and low-risk for patient outcome.

Several CLIA-waived tests are available commercially for streptococcus group A, which detect the antigen directly from a throat swab, says Marilyn Roth MT (ASCP), laboratory manager at Medical Associates Clinic, a multi-specialty clinic in Dubuque, Iowa, that operates several satellite labs with CLIA-waived status. The direct optical observation tests are reported using CPT code 87880 but must include the modifier -QW (CLIA waived test) if performed at a CLIA waived-status lab, she continues. The -QW modifier is required for these labs to be reimbursed, otherwise it is assumed that the lab is performing a non-waived test.

Methodology Determines Code

Besides the direct optical observation tests (87880), CPT points to three other possible codes for use in place of deleted code 86588. Two of these methods also involve antigen detection, says Bonifas. They are 87430 and 87081. Selecting the correct code for billing depends on which test methodology is used.

The culture [87081] is commonly used as a back-up to the rapid strep test [87880], says Werner. If a patient presents with a sore throat and beefy red pharynx, many physicians will order two swabs, one for a rapid strep test and one for a culture, if necessary. If the physician office lab conducts the rapid strep test and the findings are positive, the second swab often is discarded and the culture is not carried out. The coding by the physicians office for this scenario would be ICD-9 code 034.0 (streptococcal sore throat) and CPT 87880.

In a different scenario, both tests might be sent to an outside laboratory. The physician may order both the rapid strep test [87880] and a culture [87081], to be performed only if the rapid strep test is negative, states Werner. The physician assigns the diagnosis code at the time of collection, and that is the code we use to bill the test. Often, the physician has assigned ICD-9 code 462 (acute pharyngitis), which is used to bill the rapid strep test and/or the culture, depending on which procedures are actually carried out.

The final code used in place of deleted code 86588 is 86403. This method is different from the others in that it screens for the presence of an antibody rather than an antigen, states Werner. The test is used for blood samples, to detect antibodies from a current or past streptococcal infection. If a latex-type agglutination test is used to screen for the presence of streptococcus group A antibody, code 86403 should be reported.

Other Streptococcus Detection Codes

Coders should be aware that there are other lab tests for streptococcus antigen or antibody detection besides the four cross-referenced in CPT to deleted code 86588, advises Werner. These are generally more definitive tests that are not used for a simple strep screen.

For example, probe techniques for streptococcus antigen detection are reported using codes 87650 (infectious agent antigen detection by nucleic acid [DNA or RNA]; streptococcus, group A, direct probe), 87651 (streptococcus, group A, amplified probe technique) or 87652 (streptococcus, group A, quantification). These tests provide a higher degree of sensitivity and specificity but are fairly expensive procedures, says Werner. Thats why these methods are not usually used by labs for a low-reimbursement test like strep screening.

Another example is a more definitive test for streptococcus antibody detection. We currently use the antistreptolysin 0 (AS0) titer, coded 86060, to identify an antecedent streptococcus group A infection, reports Werner. This blood test is used to diagnose streptococcal involvement in disease processes such as rheumatic fever [390-392.x] and its possible complications of carditis [391.x, 714.2, 429.89], rheumatoid arthritis [714.0] or glomerulonephritis [580.x].

The bottom line is, correct coding for streptococcus detection depends on familiarity with the lab method used, advises Werner. Individuals responsible for billing must be informed which one of the many strep codes accurately describes the test that is ordered and performed. In other words, communication is the key to compliance and reimbursement for streptococcus detection tests.