Polypharmacy interventions result in sustained decreases

A study that set out to determine whether you could improve drug safety for managed care patients through reduction of polypharmacy found a decline in drug costs and in numbers of prescriptions in a population at high risk for adverse drug events brought on by polypharmacy. Polypharmacy — when a patient is prescribed and takes more drugs than is warranted clinically — affects more than 40 percent of American adults ages 65 years and older.

Researchers performed two interventions, one year apart, in this high-risk population that was identified from six months of pharmacy claims. These patients were identified because of their use of five categories of high-risk drug combinations, referred to as polypharmacy events. The intervention program consisted of clinical pharmacists performing drug therapy reviews, educating physicians and patients about drug safety and polypharmacy, and working with physicians and patients to correct polypharmacy problems.

After the first intervention, overall rates of polypharmacy events decreased from 29.01 to 9.43/1000 patients (67.5 percent reduction). The number of prescriptions/member/month decreased from 4.6 to 2.2 (52.2 percent reduction), prescription cost/member/month decreased from $222 to $113 (49.1 percent reduction), and overall institutional drug cost was reduced by $4.8 million.

Six months after the second intervention, the overall rate of polypharmacy events was reduced from 27.99 to 17.07/1000 (39 percent reduction), the number of prescriptions/member/month decreased from 4.5 to 4.0 (11.1 percent reduction), and prescription cost/member/month declined from $264 to $239 (9.5 percent reduction). Overall institution drug costs were reduced by $1.3 million.

The study was published in Pharmacotherapy.

Rates of polypharmacy events/1,000 patients

Source: Zarowitz BJ, Stebelsky LA, Muma Bk, Romain TM, et al. Reduction of high-risk polypharmacy drug combinations in patients in a managed care setting. Pharmacotherapy 2005;25(11):1636-1645. Also available at www.medscape.com (verified 11/25/05).

MANAGED CARE December 2005. ©MediMedia USA