07 de març 2014

Cost-effectiveness with uncertain effectiveness

Gene expression testing is quite different from genetic testing. Gene expression refers to epigenetic regulation of genes that occur without alteration of DNA. I've covered such topics several times in this blog. Today, I would like to focus on a recent published work on a new test  that assesses whether or not a patient's chest discomfort or other symptoms are due to obstructive coronary artery disease. Sounds interesting, since angiography is a costly technology.
A quick look at this recent article will raise new doubts. As you know, there is no need for cost-effectiveness analysis when effectiveness is uncertain. When talking about testing effectiveness means, sensitivity and specificity, AUC and so on. But what happens when the seller (or the model) decides about the threshold and afterwards focuses on negative predictive value of 96% and provides the desired value?. The threshold is only an option in the model. Why not change it?. There is a circular reasoning on that.
My concern is that health economics should look in detail at such issues. It is not an issue of conflicts of interest. In this case any health economist should avoid entering such territory.