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Studies examine pharmacy workload and medication errors and cost savings of hospital barcode medication systems

The more medications that community pharmacists dispense each day, the greater the likelihood of medication errors. Aside from the sheer volume of prescriptions they need to fill, community pharmacists are often interrupted by telephone calls from doctors or patients and questions from pharmacy support personnel or in-store customers, which may also influence medication errors. Indeed, higher pharmacist and pharmacy workload at community pharmacies does increase the risk of dispensing medications with the potential for drug-drug interactions (DDIs), concludes a study supported by the Agency for Healthcare Research and Quality (HS10385).

Hospitals incur $2,200 in additional costs per adverse drug event, including DDIs, at a cost nationally of $2 billion per year. Implementing a barcode-assisted medication dispensing system in hospital pharmacies can result in a positive financial return on investment for the hospital, concludes a second AHRQ-supported study (HS14053).

Both studies are briefly discussed here.

Malone, D.C., Abarca, J., Skrepnek, G.H., and others. (2007, May). "Pharmacist workload and pharmacy characteristics associated with the dispensing of potentially clinically important drug-drug interactions." Medical Care 45(5), pp. 456-462.

Community pharmacies and pharmacists with a greater workload are more likely to dispense medications with potential DDIs (such as coprescribing the anticoagulant warfarin with nonsteroidal anti-inflammatory drugs), according to this study. The researchers analyzed the association between pharmacist workload and pharmacy characteristics of 672 community pharmacies with dispensing of medications with potential DDIs over a 3-month period. Pharmacies were typically fairly busy. They filled an average of 1,375 prescriptions per week and submitted 17,948 pharmacy claims to participating pharmacy benefit managers. They had 1.2 full-time-equivalent pharmacists per hour the pharmacy was open, and pharmacists processed a mean of 14 prescriptions per hour. The relative risk for dispensing a potential DDI increased by just over 3 percent for each additional prescription processed per pharmacist hour and by 10 percent for each additional prescription per pharmacy staff hour.

These results suggest that as pharmacists become busier, they have less time to evaluate DDI warnings or to act on those warnings. Pharmacies with automated telephone systems for prescription orders were also significantly more likely to dispense medications with potential DDIs. Pharmacies with higher rates of dispensed potential DDIs were also more likely to have computer systems that provided DDI alerts and clinical information.

Maviglia, S.M., Yoo, J.Y., Franz, C., and others. (2007, April). "Cost-benefit analysis of a hospital pharmacy bar code solution." Archives of Internal Medicine 167, pp. 788-794.

Barcoding of medications can reduce hospital pharmacy dispensing errors that typically involve the incorrect medication, strength, or dosage form. For example, after implementing a barcode-assisted dispensing system, one hospital pharmacy reduced the rate of potential adverse drug events (ADEs) from dispensing errors by 63 percent (from 0.19 to 0.07 percent). In addition, implementation of this system resulted in a positive financial return on investment for the hospital, according to this study.

The authors performed a cost-benefit analysis of the medication barcode system within a large hospital pharmacy. They examined the net financial cost and benefit of implementing the system over a 5-year period. In inflation- and time-value-adjusted 2005 dollars, total costs during 5 years were $2.24 million ($1.31 million in one-time costs during the initial 3.5 years and $342,000 per year in recurring costs starting in year 3). The primary benefit was a decrease in ADEs from dispensing errors (517 ADEs averted annually), resulting in an annual savings of $2.2 million. The net benefit after 5 years was $3.49 million. The break-even point for the hospital's investment occurred within 1 year after the system became fully operational.

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