Appeal type: Experimental/Investigational
Decision: Upheld

Diagnosis: Diarrhea. 
Treatment: Gastrointestinal Pathogen Panel Testing (87507). 
The insurer denied: Gastrointestinal Pathogen Panel Testing (87507). 
The denial is upheld. 

The patient is an adult male patient who had diarrheal disease. The provider ordered gastrointestinal pathogen panel testing (87507). This was a 12-25 panel examination of the patient's stool as evaluation for his chronic diarrhea. The plan declined coverage as the criteria were not met. 

The health plan should not cover the proposed treatment. 

Items that do not have strong, research-based evidence to permit conclusions and/or clearly define long-term effects and impact on health outcomes (i.e., that have not yet been shown to be consistently effective for the diagnosis or treatment of the specific condition for which it is sought) are considered experimental/investigational. Strong, research-based evidence is identified as peer-reviewed published data derived from multiple, large, human, randomized, controlled clinical trials or at least one or more large, controlled, national, multi-center, population-based studies. 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 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, Giardia (G. lamblia only, also known as G. intestinalis, and G. duodenalis), Norovirus GI/GII, Rotavirus A, Salmonella, Shiga Toxin-producing Escherichia coli (STEC) stx1/stx2, and Shigella (S. boydii, S. sonnei, S. flexneri, and S. dysenteriae). 
In one study, 500 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 (two out of three) result obtained by molecular and/or antigen assays. Among 500 clinical stool samples, the assay showed greater than 90% agreement for all targets. 
The American College of Gastroenterology (ACG) clinical guideline, Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults states: "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 testing was experimental/investigational.