Clin Biochem Rev Vol 29 November 2008

In summary, the development of hormone and tumour marker analysis has radically changed clinical endocrinology practice since the development of immunoassay four decades ago. Further improvement in analysis has been provided by mass spectrometry for steroid hormones and possibly soon for peptide hormones. We must ensure that these new tests are subjected to quality evidence-based study so that only diagnostically useful tests are introduced in the future.

Four phases in the architecture of diagnostic research.
Phase I—Determining the normal range of values for a diagnostic test through observational studies in healthy people
Phase II—Determining the diagnostic accuracy through case-control studies, including healthy people and (a) people with known disease assessed by diagnostic standard and (b) people with varying severity of disease and (c) people with suspected disease
Phase III—Determining the clinical consequences of introducing a diagnostic test through randomised trials
Phase IV—Determining the effects of introducing a new diagnostic test into clinical practice by surveillance in large cohort studies