Medication cost information in a computer-based patient record system - Impact on prescribing in a family medicine clinical practice

Background: Medications account for 8% of national health care expenditures , and prescription drugs are a focus of cost containment measures. Physicia ns have limited knowledge about drug costs, and no method of providing this information has demonstrated sustained cost reductions. Objective: To determine the impact of cost information in a computer-based patient record system on prescribing by family physicians. Methods: A yearlong, controlled clinical trial was conducted at the Family Medicine Center, Medical University of South Carolina, Charleston, a group practice staffed by attending physicians and residents. Prescription cost i nformation was included in the computer-based patient record system used at the center. During a 6-month period, cost information was not displayed; d uring the subsequent 6-month intervention period, costs were displayed at t he time of prescribing. An intention-to-treat analysis was used to compare prescription costs between the central and intervention periods for all med ications prescribed, and stratified analyses for several medication and phy sician factors were performed. Results: A total of 22 883 prescriptions were written during the 1-year stu dy period. The mean +/- SD cost per prescription in the control period was $21.83 +/- $27.00 (range, $0.01-$510.00), and in the intervention period wa s $22.03 +/- $28.12 (range, $0.01-$435.96) (P =.61, Student t test). Increa ses in mean prescription cost and proportion of total costs were identified in 4 medication classes: antibiotics, cardiovascular agents, headache ther apies, and antithrombotic agents. Decreases in mean prescription cost and p roportion of total costs were identified in 5 medication classes: nonsteroi dal anti-inflammatory drugs, histamine type 2-receptor antagonists and prot on pump inhibitors, ophthalmic preparations, vaginal preparations, and otic preparations. Conclusions: In this setting, the provision of real-time computerized drug cost information did not affect overall prescription drug costs to patients , although differences in individual medication classes were observed. The negative results of this study may reflect confounding due to the use of hi storical controls, suboptimal timing of the intervention in the prescribing process, susceptibility bias at the study site, or the insensitivity of pr escribing habits to cost information.