(345) Medication Errors in EudraVigilance: Signals of Disproportionate Reporting Among Age Groups

Background: Medication errors (MEs) are frequently reported, but differences among age groups are underexposed.

Objectives: To identify conspicuous signals of disproportionate reporting (SDRs) among age groups for the most frequently reported drugs in the European Medicines Agency's EudraVigilance (EV).

Methods: Spontaneous adverse drug reaction reports from EV reported between 2002-2021 were used. A ME was defined using the preferred terms from the narrow Standardised Medical Dictionary for Regulatory Activities® Query for MEs. Drug names were assigned an Anatomical Therapeutic Chemical (ATC) classification code by the AIOLI program. SDRs were expressed as reporting odds ratio (ROR) with 95% confidence interval (CI). Analyzed age groups were 0-1 month, 2 months-2 years, 3-11 years, 12-17 years, 18-64 years, 65-85 years, and ≥85 years.

Results: Of the 9,662,345 reports, 267,262 (2.8%) contained at least one ME, a total of 300,324 MEs, for 429,554 drugs. ME reports were frequently on females (148,009; 55.4%), reported by healthcare professionals (155,711; 58.3%), originated predominantly from the USA (98,716; 36.9%), followed by France (26,678 ; 10.0%), and showed a median patient age of 50 years (interquartile range: 26-68).

Most MEs were reported for the vaccine against human papillomavirus (ATC: J07BM01; 11,086 MEs, 57% being inappropriate schedule of product administration), showing an ROR =1.5 (95% CI: 1.3-1.7; 314 MEs) for age group 3-11 years, ROR=22.7 (95%CI: 17.3-29.7; 78 MEs) for age group 2 months–2 years, and an ROR=46.9 (95%CI: 19.1-115; 7 MEs) for the age group 65-85 years. The SDR for the live attenuated vaccine against Herpes Zoster (ATC: J07BK02) was signified by an ROR ranging from 45.9-78.3 among all age groups (exc. 0-1month) while for the entire database the ROR=36.3 (95%: 35.1–37.5; 4756 MEs, 27% being incorrect administration route). The most distinct result was found for etonogestrel (ATC: G03AC08) which showed an ROR=60.3 (95%CI: 14.4-252.3; 3 MEs) for the age group 65-85 years, while for the entire database the ROR=3.4 (95%CI: 3.3-3.5; 4501 MEs, 59% incorrect administration duration). Risperidone (ATC: N05AX08) stood out with an ROR=9.1 (95%CI: 6.8-12.1; 57 MEs) for age group 2months-2years, while for all other groups the ROR ranged from 1.2 (95%CI: 1.1-1.4) to 1.8 (95%CI: 1.5-2.1), counting 2105 MEs, 22% being inappropriate schedule of product administration, in the entire database.

Conclusions: Results indicate differences in magnitude of SDRs among various age groups. Highlighted SDRs are a small selection of results, with many more results to be discussed. SDRs based on age groups should be interpreted with caution as some are supported by low case counts. Nonetheless, these SDRs might prompt stakeholders for an early root-cause analysis to mitigate future MEs among specific age groups.