Barriers to medication adherence can be overcome by comprehensive pharmacy program

December 8, 2008

A multifaceted pharmacy intervention improves medication adherence in seniors, according to Jeannie Kim Lee, PharmD.

A multifaceted pharmacy intervention improves medication adherence in seniors, according to Jeannie Kim Lee, PharmD.

Currently, adults 65 years or older comprise 14 percent of the U.S. population yet receive 36.5 percent of all prescription drugs. With many of these older patients on multiple drugs, some with complex regimens, poor medication adherence has become America's "other drug problem," says Dr. Lee, clinical assistant professor, Pharmacy Practice and Science, University of Arizona College of Pharmacy, Tucson.

Programs that focus on only one aspect, such as education or convenience packaging, have not had yielded durable improvements in medication adherence.

Dr. Lee studied the impact of a comprehensive pharmacy care program on medication adherence and levels of blood pressure and low-density lipoprotein (LDL) cholesterol levels in men and women 55 years or older who were taking four or more chronic medications daily.

The program included several components, such as simplifying patients' drug regimens by tailoring time regimens; the use of custom blister packs that combined up to nine medications per blister; and comprehensive medication charts for patients that listed the brand and generic names of the drugs, the indication, dosage, frequency, and special instructions. The patients were instructed to take their medication charts to each medical appointment, at which time the charts were updated with any changes to the regimen. Patients were followed every 2 months.

The study included a run-in phase (months 1 and 2), a first phase in which 174 patients received the comprehensive intervention (months 2 to 8), and a second phase in which 159 of the patients in phase one were randomized to continued comprehensive intervention or usual care.

Adherence rates were determined by pill counts.

Adherence improved from 61.2 percent at the end of the run-in phase to 96.9 percent at the end of phase one. "This improvement resulted in a 16-fold increase in participants taking 80 percent or more of all medications," says Dr. Lee. At the end of phase one, systolic blood pressure (SBP) decreased from a mean of 133.2 mm Hg to 129.9 mm Hg (p = .02), mean diastolic blood pressure (DBP) improved from 70.5 mm Hg to 69.7 mm Hg (not significant), and mean LDL cholesterol declined from 91.7 mg/dl to 86.8 mg/dl (p = .001).

At the end of phase 2 (14 months), adherence in the group that was randomized to usual care fell to 69.1 percent, whereas adherence was maintained at 95.5 percent in the group that continued on the comprehensive intervention (p

Dr. Lee notes that other studies have linked medication adherence to fewer hospitalizations in older patients.