Background Few data are available regarding the prevalence of potentially dangerous drug-
drug, drug-laboratory, and drug-disease interactions among outpatients. Our objectives
were to determine how frequently clinicians prescribe drugs in violation of black box
warnings for these issues and to determine how frequently such prescribing results in harm.
Methods In an observational study of 51 outpatient practices using an electronic health
record, we measured the frequency with which patients received prescriptions in violation of …