Hierarchies of evidence in evidence-based medicine

Impressions: this looks like extensively-researched scholarly work. It raises questions about the veracity of hierarchical model of evidence-based medicine (EBM).

However, I was lazy and skipped to the conclusion[1] to determine most of that. People with experience of both statistics and healthcare policy would have more useful thoughts.

[1] - http://etheses.lse.ac.uk/3284/1/Blunt_heirachies_of_evidence...