Impact of electronic prescribing on medication use in ambulatory care.

OBJECTIVES: To investigate differences before and after rollout of electronic prescribing (e-prescribing) in (1) patients' primary adherence to newly prescribed medications, (2) patients' understanding of how to use their medications, and (3) multiple pharmacy use. STUDY DESIGN: Postvisit interviews and follow-up phone calls were done with 344 patients at an academic general internal medicine clinic. METHODS: Patient interviews and follow-up phone calls were done (1) before e-prescribing, (2) 1 to 6 months after e-prescribing, and (3) 12 to 18 months after e-prescribing. RESULTS: Overall, rates of abandoned prescriptions were 6.9% before e-prescribing, 10.6% 1 to 6 months after e-prescribing, and 2.5% 12 to 18 months after e-prescribing (P = .07). There was a reduction in awareness of the indication for a newly prescribed medicine among patients after e-prescribing (95.4%, 97.9%, and 89.8%, respectively; P = .03). There was a decrease in patients' ability to demonstrate proper use of their new medicine after e-prescribing (69.0% before e-prescribing, 67.1% 1-6 months after e-prescribing, 51.9% 12 -18 months after e-prescribing; P = .02). There was an increasing trend in the percentage of patients using multiple pharmacies after e-prescribing was implemented. CONCLUSIONS: We found both potential benefits and unexpected consequences as a result of the rollout of electronic prescribing. Adaptation to e-prescribing might be improved with outreach and education, including explicitly informing patients of the change during the first months of rollout. Tangible prescription information for reminder purposes only may also be beneficial.