Promises and pitfalls of the

The development of large-scale outcomes databases has tremendous potential. They are treasure troves of invaluable information. Never before have we had the accumulation of so much data on treatment effectiveness across so many organizations and clinicians. In this issue we outline several collaborative efforts to build and maintain larger, cross-system databases. However, the methodological and ethical barriers posed are daunting, as described in the Letter from the Editor (see page 11). Here, in Dialogue, four eminent leaders of the quality agenda address those barriers from their different perspectives. They examine the promises of these databases to demonstrate accountability and advance knowledge, and they evaluate the many obstacles that must be overcome for that promise to be fully realized. Is this bounty of data to be opened, closed, or something in between? - Eds.