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

Sir,-
Colleagues Hemingway et al. (BMJ 2003;327:895-8) have increased out
understanding on the impact of coronary heart disease, especially if the
condition goes undiagnosed. My concern is whether this information has
been obtained in an ethically transparent way. Many of their subjects had
the condition already in 1985, but did not know about it. When did the
authors learn about the diagnoses? The article does not state when the
data was analyzed nor whether the study was approved by an ethics
committee.

Competing interests:
None declared