Use of computer alerts to prevent the inappropriate use of metformin in an inpatient setting

Metformin is recommended as initial therapy for most patients with type 2 diabetes mellitus. Its most serious adverse effect, lactic acidosis, is a rare entity with a high mortality rate. Despite well-publicized contraindications, metformin is inappropriately prescribed to many hospitalized patients.

To determine the efficacy of computer alerts at reducing inappropriate metformin prescribing.

Retrospective chart review of all hospitalized patients who received an order for metformin, before (n = 144) and after (n = 147) an intervention designed to reduce inappropriate administration. This intervention included 2 "hard-stop" computer alerts that prevented prescribing metformin to patients with renal dysfunction and in critical care or postoperative units; and 2 "soft" alerts that fired when no serum creatinine was available or the patient was in an outpatient surgical unit. Charts were reviewed for the presence of contraindications: renal insufficiency, congestive heart failure, recent myocardial infarction, surgery, or intravenous contrast use within 48 hours of metformin administration.

In the preintervention group there were 47 violations compared with 13 violations in the postintervention group (P < .001). The greatest improvement was in surgical patients (39 violations vs 11, P < .001).

Computer alerts at order entry were effective in decreasing the inappropriate prescribing of metformin in an inpatient setting.