Randomized trial to improve laboratory safety monitoring of ongoing drug therapy in ambulatory patients.

STUDY OBJECTIVE

To determine whether an electronic tool effectively increases the percentage of patients receiving laboratory monitoring during ongoing drug therapy.

DESIGN

Randomized trial.

SETTING

Outpatient medical offices of a group model health maintenance organization.

PATIENTS

A total of 9,139 patients prescribed ongoing therapy with any of 14 drugs, resulting in 4,871 patient-drug combinations in the intervention group and 4,780 in the usual-care (control) group.

INTERVENTION

Physicians and pharmacists jointly developed monitoring guidelines based on published recommendations. Pharmacists were electronically alerted to missing laboratory results and then ordered tests, reminded patients to undergo tests, and reviewed and managed abnormal results.

MEASUREMENTS AND MAIN RESULTS

In the intervention group, 64% of patientdrug combinations were monitored, whereas in the usual-care group 58% were monitored (p < 0.001). Differences in monitoring were observed in the intervention versus usual-care groups for amiodarone (71% vs 55%, p<0.01), theophylline (54% vs 28%, p<0.001), carbamazepine (49% vs 32%, p<0.001), lithium (42% vs 28%, p<0.01), phenytoin (44% vs 33%, p<0.001), and metformin (72% vs 67%, p<0.001). Of 1981 laboratory tests ordered, 1,472 (74%) were completed. The tests revealed 181 serum drug concentrations outside the therapeutic range and 126 abnormal serum creatinine, alanine aminotransferase, aspartate aminotransferase, and thyroid-stimulating hormone levels, and complete blood counts.

CONCLUSION

A computerized tool plus collaboration of health care professionals effectively increased the number of patients who received laboratory safety monitoring of drug therapy.