Prevalence and risk factors for modified prescriptions in an Irish community pharmacy

Background: Despite a dearth of knowledge on the causes of prescribing errors in medical practice, and the rates of prescribing errors among certain patient groups, little Irish research exists to address this issue. One possible reason for this is that the analysis of prescription modification is not part of the recognised job description of a pharmacist. Aims: To investigate the prevalence, nature and risk factors for prescription modifications in an Irish community pharmacy. Methods: A cross-sectional study was performed to examine prescriptions dispensed in an Irish community pharmacy over a period of five weeks. Results: In total, 866 prescriptions were examined. The overall prevalence of prescribing errors and prescription modifications was 17.9% (155), with a mean of 31 modifications per week. Prescription only medicines (POM) comprised 94.8% (147) of the modifications, of which 87% (128/147) were prescription errors requiring a simple clerical clarification before dispensing could occur. The remaining 13% (19; average of 3.8 per week) were prescribing faults with potential clinical consequences if left unaltered. Half (51%) of all POM modifications occurred through consultation with the patient or their representative. The following factors were associated with increased risk of POM modifications: being a female patient (OR=1.605, 95% CI 1.104-2.333, p=0.013); and, being prescribed drugs in the following therapeutic areas – musculoskeletal (OR=1.906, 95% CI 1.023-3.551, p=0.042), and genitourinary system and sex hormones (OR=3.691, 95% CI 2.255-6.042, p Conclusions: The majority of prescribing errors modified involved non-serious clerical errors. However, an average of 3.8 POM prescriptions with potential clinical consequences were modified weekly.