Detecting prescribing problems through drug usage review: a case study.

A retrospective drug usage review was performed on 1,033 randomly sampled prescription orders from the outpatient pharmacy of a hospital and clinic system. Prescription orders were screened in accordance with criteria based on daily dosage, length of therapy or quantity dispenced, diagnosis, and labeling. The results of the study point to a number of potential prescribing problems. In addition, the study demonstrates the feasibility of collecting and analyzing drug usage data on a retrospective basis.