Appeal type: Experimental/Investigational
Decision: Upheld

Diagnosis: Diarrhea.
Treatment: Polymerase Chain Reaction Gastrointestinal Test (87507).
The insurer denied the Polymerase Chain Reaction Gastrointestinal Test (87507).
The denial is upheld.

The patient is a male. He presented with fecal leakage. He has a history of E coli (Escherichia coli) gastroenteritis and C difficile (Clostridium difficile) infection, as well as perianal fistula. The provider ordered stool studies to evaluate for infection including the gastrointestinal pathogen panel.

No, the health plan should not cover the Polymerase Chain Reaction Gastrointestinal Test (87507).
Stool based gastrointestinal panels (example - xTAG Gastrointestinal Pathogen Panel (GPP)) are multiplexed nucleic acid tests intended for the simultaneous qualitative detection and identification of multiple viral, parasitic, and bacterial nucleic acids in human stool specimens.   The xTAG GPP (Gastrointestinal Pathogen Panel) test detects 11 Gastrointestinal Pathogen targets: Campylobacter (C. jejuni, C. coli and C. lari only), Clostridium difficile toxin A/B, Cryptosporidium (C. parvum and C. hominis only), Escherichia coli O157, Enterotoxigenic Escherichia coli (ETEC) LT/ST (heat-labile/heat-stable), Giardia (G. lamblia only, also known as G. intestinalis and G. duodenalis), Norovirus GI (genogroup I)/GII (genogroup II), Rotavirus A, Salmonella, Shiga Toxin-producing Escherichia coli (STEC), and Shigella (S. boydii, S. sonnei, S. flexneri and S. dysenteriae).

In one study, five hundred clinical stool specimens (retrospective/stored samples=270; prospective samples=230) were evaluated. Results were compared to a reference standard result, which was defined as an organism identified by routine culture, microscopy, or a consensus (2 out of 3) result obtained by molecular and/or antigen assays. Among 500 clinical stool samples, the assay showed > [greater than] 90% agreement for all targets.

No, the Polymerase Chain Reaction Gastrointestinal Test (87507) is not more beneficial.
Per ACG (American College of Gastroenterology) clinical guideline, Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults: "Molecular diagnostic tests can provide a more comprehensive assessment of disease etiology by increasing the diagnostic yield compared with conventional diagnostic tests. They are also faster, providing results in hours rather than days. The new diagnostics' best applicability is for the clinician in practice, seeing one patient at a time rather than in the public health setting, e.g., in outbreak investigations. One potential drawback of molecular technologies is the need to predefine the particular microbes being sought. In addition the significance of an identified organism may not be clear as these molecular technologies, which involve nucleic acid amplification, are limited to our existing knowledge of a microbes' genome and do not discriminate between viable and non-viable organisms. As a result they can detect microbes at non-pathogenic levels. Given the high rates of asymptomatic carriage of enteropathogens, this can be a considerable problem. To confound matters, further multiplex techniques are more commonly associated with increased detection of mixed infections and the relative importance of each pathogen may be unclear. Before bacterial culture is discarded entirely, it is important to acknowledge that multiplex molecular diagnostics do not yield isolates that can be forwarded to public health laboratories."

Further studies are needed to determine if the efficacy of gastrointestinal panels is greater than conventional stool culture. Therefore, the recommendation is not to cover the service.