Exploring the frequency and location of prescribing errors in the use of topical glaucoma medications.

Importance: Very little is known about health-care professional related prescribing errors within the glaucoma setting.

Background: This study aims to quantify these errors and to explore where they occur along the prescribing pathway.

Design: Cross-sectional study of patients attending a specialty glaucoma clinic over a 5-month period.

Participants: Data was collected for 109 patients.

Methods: We compared glaucoma drop regimes from four different sources: As documented in the hospital notes for the last appointment, the letter sent to the General Practitioner (GP), patient's self-reporting and bottles/prescriptions brought to the clinic appointment.

Main Outcome Measures: Discrepancies were identified and errors were grouped into one of four categories depending on where in the prescribing pathway they occurred: Incorrect prescribing of the drops by the clinician, incorrect prescribing of the drops by the GP/failure to provide a repeat prescription, incorrect dispensing of the drops by the pharmacist and possible non-adherence by the patient.

Results: There was a total of 217 individual prescription items involving 266 active ingredients. Seventy-one prescription items out of 217 (33%) had an error, of this 53 (75%) were due to possible patient non-adherence and 18 (25%) were process related errors made by health-care professionals.

Conclusions And Relevance: An error was identified in 33% of prescriptions. About 8.3% of prescriptions had a health-care professional related process error. These errors are preventable and recognition of these is important to maximize drop adherence and minimize disease progression, requiring increased consultations and interventions with quality of life and health economic consequences.