Canadian wins T-Shirt competition

In a study titled Cost-effectiveness of a new interferon-based blood assay, QuantiFERON®-TB Gold, in screening tuberculosis contacts researchers from Vancouver found that

The most economically attractive strategy was to administer QFT-G in BCG-vaccinated contacts, and to reserve TST for all others

However once mitigating factors were included QFT-G became more cost effective;

Assuming a higher prevalence of recent infection, faster conversion of QFT-G, a higher rate of TB reactivation, reduction in utility or greater adherence to preventive treatment resulted in QFT-G becoming cost-effective in more subgroups.

Had they included more mitigating factors (lack of subjectivity, cost of running dual diagnostic systems, shortage of diagnosticians, predictive value nof QFT, reduction in hepatoxicity, increased user confidence etc) who knows how much more cost effective QFT would become.

You can only wonder just how much these studies cost and why it is that they have to duplicate work done elsewhere - dont these people trust their peers?