research has been enshrined in the US Healthcare Reform Law of 2010.1,2 The law mandates the creation of a Patient-Centered Outcomes Research Institute (PaCORI), which will establish national research priorities and methodological standards, and will carry out research. The UK's National Institute for Health and Clinical Excellence, set up in 1999, was the world pioneer in this area. Though the organizational structure and duties of the American and British Institutes vary (e.g., the U.S. Institute is barred by law from considering the cost-effectiveness of interventions), both institutes have an overarching common goal: to improve the public's health through research on the relative effectiveness of different interventions. These interventions include medical treatments, changes in health care organization and delivery, community and workplace interventions, individual lifestyle modifications, etc. Upon first hearing the above, many epidemiologists quickly retort: “Isn't comparative effectiveness research something we have always done under different names?” The answer is yes, of course. Epidemiologists are natural comparative effectiveness researchers. In fact, the new U.S. law stipulates that the Board of Governors of the Institute shall collectively have scientific expertise in “epidemiology, decisions sciences, health economics, and statistics.”1 And yet most of the methodological discussions about comparative effectiveness research have so far taken place outside of epidemiologic journals and departments. In an attempt to jumpstart a discussion on comparative effectiveness research among epidemiologists, this issue of EPIDEMIOLOGY includes four pieces3-6 on the use of observational healthcare databases, all written by leading epidemiologists in this old new field. Which brings us to the main point of this editorial. The editors of EPIDEMIOLOGY encourage the submission of high-quality papers on evaluation of interventions with public health significance. If your research involves healthcare databases, we invite you to read the commentaries published in this issue, and take their recommendations to heart when preparing your paper. A summary and extension of some of the key recommendations follow. Healthcare databases are attractive because they put large quantities of data into our hands. But let us be ready to say no to quantity if it compromises quality too much. Both Weiss3 and Ray4 provide examples in which incomplete or incorrect ascertainment of exposure, outcome, confounders, eligibility criteria, or linkage variables resulted in incorrect conclusions. As Weiss3 puts it, “Just because an analysis can be done does not mean it should be done.” At the very least, epidemiologists should work closely with those who constructed the database, or be ready to invest enough time to understand its nooks and crannies. The quality of information on health outcomes is particularly important. Many validation studies have shown that database information on outcomes cannot just be accepted “as is” (for example, see Ives et al.,7 Hernán et al.,8 Garcia Rodriguez and Ruigomez,9 and Saunders et al.10). Authors submitting to EPIDEMIOLOGY need to provide quantitative assessment of the quality of the health outcomes used in their study. If you did not conduct your own validation study, be prepared to cite others who did. Validation studies increase cost and take time, but they may be the difference between cranking out analyses and sound epidemiologic research. Even if the data in your study, including confounders, are correctly measured, there is still room for trouble. Stürmer et al5 describe examples in which bias arose because of inappropriate choice of comparison groups. Dreyer6 stresses the importance of guidelines for the proper conduct and reporting of comparative effectiveness research using observational data. These guidelines are certainly helpful but, unlike several medical journals, EPIDEMIOLOGY does not require authors to submit their papers to a standardized test.11 Passing a driving test may be required to drive a car on the highway but not to race it professionally. If your paper is the equivalent of car that deserves to be driven on the race track, we