Regarding “The Clinical and Economic Burden of Norovirus Gastroenteritis in the United States”

To the Editor—In their recent article, Bartsch et al report the calculated economic costs of rotavirus infection in the United States using a Monte Carlo simulation model [1]. This study importantly concludes that rotavirus infection produces a heavy economic burden on the healthcare system in the United States. The authors’ Monte Carlo simulation decision tree (Figure 1) evaluates several parameters from established data sources and estimates the cost of norovirus illness through the model. Included in their analysis is productivity loss for both time of illness and if death occurs.

Figure 1.

After reviewing the decision tree, we are concerned that an error occurred in either the decision tree figure, the Monte Carlo simulation calculations, or possibly both. Our specific point of concern involves the branch point where a patient lives in the algorithm. In 5 of the 6 times where this branchpoint occurs, the figure indicates that survival is associated with lifetime productivity losses for the patient (labeled 1–5). We believe that death would be associated with lifetime productivity losses and that the figure is incorrect. However, in 1 of the 6 times where this branchpoint occurred, it is death that is associated with lifetime productivity losses (labeled 6). These discrepancies lead us to be concerned that 1 or more of the Monte Carlo simulation calculations could have been run in error.

We think it would be prudent for the authors to reevaluate the decision tree figure and recheck the underlying equations used for their Monte Carlo simulation to clarify if any errors occurred.

Notes

Potential conflicts of interest. The authors: No reported conflicts of interest.

Both authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.