Screening for expired medications in automated dispensing cabinets

Results of a study to quantify rates of identification of expired medications in automated dispensing cabinets (ADCs) are reported.

A pre-post analysis was conducted to determine the effect of various types of ADC audits on rates of finding expired medications in ADCs. For the experimental phase of the study, 4 ADCs at the main campus of an academic medical center were randomly assigned to receive one of 4 interventions: (1) monthly audits of all ADC pockets, (2) monthly audits of matrix (open pocket) drawers only, (3) monthly audits of unassigned pockets only, and (4) no additional intervention.

At baseline, rates of finding expired medication doses in the 4 ADCs ranged from 0.4% to 0.7%. During the 3-month experimental period, rates of finding expired medication doses ranged from 0.1% to 0.3%. During a final audit 1 month later, the ADC targeted for monthly audits of all pockets was found to contain no expired doses, with an overall improvement in expired-dose rates for all audited ADCs observed over the course of the 4-month study. The average time to perform a full audit for an ADC with about 340 pockets was 1 hour, or 15 seconds per pocket. The average time to perform matrix drawer-only audits averaged around 45 minutes, or 11 seconds per pocket. The average time to perform audits of unassigned matrix drawers averaged 30 minutes, or 10 seconds per pocket.

Auditing of all ADC pockets on a monthly basis appears to be an effective method of reducing the rate of identification of expired medications in ADC pockets.