To the Editor I read with interest an Original Investigation by Valencia and colleagues1 published in a recent issue of JAMA Internal Medicine and wish to share some thoughts. The ordering and interpretation of laboratory tests by resident physicians in teaching hospitals is an important and integral part of their training. It has long been recognized that laboratory testing in teaching institutions may be excessive.2 With the implementation of diagnosis-related group reimbursement for hospital admissions, greater emphasis was placed on length of hospital stay than efficient laboratory use.