Well, math is one of those things where (in most cases) anyone (...with the right knowledge in the field...) can verify the results (mostly) relatively easily and cheaply.

For physics, it depends.. is it just "applied math" (so, verified easily), is it a CERN-type (LHC,...) experiment (hard to replicate, unless well.. you work at CERN), where many many people process the data, or is it something that is done only in your "lab", and hard for others to replicate.

On the other hand, finding thousands of patients and running a study is practically always hard and expensive.