Prognosis of angina with and without a diagnosis: 11 year follow up in the Whitehall II prospective cohort study

I fear I am missing something.

To me this paper suggests that between 1985 and 1999 that workers
with diagnosed and presumably treated angina fared no better than
colleagues whose angina remained undiagnosed.

I think we should fall back on the "two different groups" argument.

Competing interests:
None declared