OBJECTIVES: Several molecular diagnostic assays (MDA) are now commercially available for the diagnosis of Clostridium difficile infection (CDI). These assays detect genomic material associated with the pathogen’s toxin A, B and/or other genes in stool samples.  Compared with the traditional CDI laboratory assay diagnostics, MDA has a shorter turn-around time and better sensitivity, but requires relatively expensive instrumentation. The impact of routine use of MDA on the economics of CDI disease (via shorter hospitalization and less morbidity) is not clear. We evaluated whether routine use of MDA reduces the healthcare costs and improves quality-adjusted life years (QALYs) for CDI patients. METHODS: We performed a decision tree analysis to compare cost effectiveness of MBD with enzyme immunoassay (EIA) and cytotoxin assay (CA) respectively, using data from published literature and experts’ opinions. Analyses were conducted from the societal perspective. Both incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB) were used as criteria for evaluation. RESULTS: The ICER shows that MDA is dominant to the other two alternatives. Using a base willingness-to-pay per QALY threshold ($150,000), the NMB of MDA vs. EIA and CA are around $4,000 and $1,500, respectively. Thus, conclusions from ICER and MDA assessments are consistent. To investigate the model robustness, we performed one-way and probabilistic sensitivity analyses. All sensitivity analyses illustrated that MDA dominated EIA and CA within the predefined ranges of input variables.

CONCLUSIONS: Our study demonstrated that the routine use of MDA for CDI patients would result in substantial savings and improved health outcomes in US patients, compared to traditional diagnostic assays for this infection. These are the first data to evaluated QALY outcomes as they may vary with diagnostic test choice for CDI.