Effect of prescriber education on the use of medications contraindicated in older adults in a managed medicare population.

OBJECTIVE: To measure the effect of pharmacy intervention programs on the percentage of older adult members filling prescriptions for one or more contraindicated medications in a managed Medicare population.

METHODS: Prescribers of potentially inappropriate (i.e., contraindicated) medications in a managed Medicare + Choice (now known as Medicare Advantage) health maintenance organization (HMO) were identified from drug claims each calendar quarter for letter and telephone contact. The initial study population was composed of members in the Medicare + Choice HMO who were aged 65 years or older and who utilized their managed care pharmacy benefit during the 4-year measurement period from 1999 fourth quarter (Q4) through 2003 Q4. The study population was expanded in 2003 Q1 to include all patients aged 65 years or older, including commercial HMO members and Medicare + Choice members. The prescribers of target (contraindicated) drugs were contacted by a letter that described the program and included a prescriber-specific list of patients who had received a potentially inappropriate drug. Each prescriber was requested to review the report and change the contraindicated drug to a more appropriate agent, lower the medication dose, or carefully monitor those patients who could not discontinue the drug. A clinical pharmacist contacted high-volume prescribers of target drugs (4 or more patients in a given quarter) by telephone to discuss the identified patients.

RESULTS: The incidence of inappropriate use of the target medications in older adults declined by 19%, from an absolute 5.3% of prescriptions in the base period (1999 Q4) to 4.3% at the end of the first 2-year period, in 2001 Q4. A change in the target drugs in 2002 Q1 from a list based upon the Beers' criteria to a list based in part on the Zhan et al. criteria was associated with a 45% reduction in the percentage (2.4%) of older adult members who received target drugs; this proportion remained essentially unchanged at 2.2% through 2003 Q4, the end of the second half of the 4-year intervention period.

CONCLUSIONS: A clinical intervention program targeting prescribers of drugs judged to be contraindicated in older adults was associated with a decline in the percentage of HMO members receiving one or more target contraindicated drugs. After a 4-year intervention period, 2.2% of older adult HMO members continued to receive one or more target contraindicated drugs.