Documentation for ARF / PSGN Evaluation

Documentation must support testing ordered for evaluation of suspected acute rheumatic fever (ARF) or post-streptococcal glomerulonephritis (PSGN). Examples of acceptable laboratory evidence include throat culture, rapid antigen diagnostic test (RADT), and rising or serial antistreptococcal antibody titers (e.g., ASO, anti-DNase B). A rise in titer from acute to convalescent samples (at least two weeks apart) is preferred evidence of antecedent GAS infection.

• Obtain and document acute and convalescent ASO and/or anti-DNase B titers when evaluating for ARF/PSGN; note timing (>=2 weeks apart) and rising titer
• Throat culture or positive RADT in context of compatible clinical presentation may serve as antecedent infection evidence
• If ASO titer is undetectable but clinical suspicion remains, consider anti-DNase B or other antistreptococcal antibody testing

Clinical Justification & Test Method Documentation

Clinical justification and method of testing should be clearly documented in the medical record. Include presenting signs/symptoms, modified Centor score or presence/absence of viral features, reason for testing (diagnostic vs. screening), and the specific test modality performed (RADT, NAAT, culture, serology).

• Record modified Centor score when used; testing generally indicated when score >=3
• Document absence of viral features (cough, rhinorrhea, oral ulcers, hoarseness) when ordering GAS testing
• Specify test type in the chart note (e.g., point-of-care RADT, NAAT, laboratory throat culture, serologic assay) to support medical necessity

Appropriate Testing Indications

Testing should be performed only for appropriate indications per guidelines: reserve testing for patients with high clinical suspicion for GAS (modified Centor >=3 or lack of viral features), symptomatic children/adolescents per pediatric guidance, and not for routine screening of asymptomatic individuals or children <3 years (except select circumstances).

• Do not test patients with clear viral symptoms (cough, rhinorrhea, conjunctivitis, hoarseness, oral ulcers)
• Do not routinely test children <3 years unless symptomatic household contact or outbreak scenario
• Use testing to guide antibiotic therapy decisions when there is intention to treat

Denial Risk / Non‑Covered Testing Triggers

Potential denial or non-coverage may occur when testing is not aligned with guideline indications. Common denial triggers include testing when modified Centor <3, testing in suspected viral pharyngitis, use of RADT as screening in asymptomatic patients, or simultaneous coding for both amplification and direct probe methods.

• Denied/not covered scenarios include: testing in suspected viral pharyngitis, RADT as follow-up to culture, RADT for asymptomatic screening, simultaneous billing for amplification and direct probe tests
• Panel assays (e.g., Solana Strep Complete, Lyra Direct Strep) and MALDI-TOF identification are listed as not meeting coverage criteria
• Certain serologic assays (anti-streptolysin O, hyaluronidase, streptokinase, NADase) are not covered except when evaluating suspected ARF or PSGN

Testing Sequence & Reflex Testing Practices

Testing sequence and reflex practices: for pediatric patients, a negative RADT performed with an assay known to have sensitivity <80% should be followed by a more sensitive NAAT or by throat culture. In adults, secondary testing after a negative RADT is not routinely required when using higher-sensitivity NAATs. Collecting a dual swab at initial specimen collection facilitates reflex testing when needed.

• Pediatric negative RADT with low-sensitivity assay: reflex to NAAT or culture
• Direct/amplified NAATs are sufficiently sensitive that negative NAATs typically do not require secondary arbitration
• Consider dual-swab collection at the initial visit to allow immediate reflex testing

Billing Considerations & Additional Provider Actions

Other provider action and billing considerations: the policy does not include step therapy rules or quantity limits in this section. Providers should avoid ordering tests explicitly listed as not covered (panel assays, MALDI-TOF, unsupported serologic assays) and should not bill for simultaneous amplification and direct probe assays for the same encounter.

• No step therapy or quantity-limit rules specified in this policy excerpt
• Avoid simultaneous coding of amplification and direct probe methods (listed as not meeting coverage)
• Refer to cited guidelines (CDC, AAP, IDSA, AHA, FDA notices, UpToDate) for clinical decision-making and documentation expectations