Does specialty board certification influence clinical outcomes?

BACKGROUND: The public seems to crave a simplistic index of 'quality', analogous to 'The Good Housekeeping Seal of Approval', for the complex endeavour of clinical medicine. The American Board of Medical Specialties (ABMS) and its member boards have purported to fill the vacuum in an effort that bears many of the earmarks of a public relations publicity campaign. The author examined the validity of the evidence touted in support of that effort.
METHODS: By applying Hill's causal epidemiologic criteria and logical and statistical inference, the author evaluated: (i) published data sources consisting of the most comprehensive collection of studies yet gathered that purports to provide evidence of the relevance of board certification to clinical outcomes, a collection presented by Sharp et al. apparently with the advice and consent of ABMS, that they posited as containing 'relevant findings', to what purpose they left unspecified; and (ii) the review article of Sharp et al.
RESULTS: The data that Sharp et al. presented provided no credible link between specialty board certification and outcomes or 'quality' of clinical care. Sharp et al. ignored the evidence of absent evidence they found and proposed enthusiastic but unjustified conclusions in support of specialty board certification as an index of clinical 'expertise'.
CONCLUSIONS: No evidence supports the touted clinical benefit of specialty board certification. Specialists in clinical medicine and surgery are unamenable to simplistic evaluation by examination, yet specialty board certification remains an ersatz standard of doctors' clinical quality in the absence of supporting evidence.