Zidovudine Compliance as Measured by Different Methods in an HIV Ambulatory Clinic

Abstract

Objective:

To measure and compare medication compliance by patient reports, pill counts, physician assessments, and electronic monitoring with the Medication Event Monitoring System (MEMS) in patients infected with HIV.

Methods:

Five patients monitored in a Veterans Affairs Medical Center HIV clinic were dispensed zidovudine for 3 months in MEMS vials. Zidovudine was refilled every month, at which time MEMS data were retrieved and pill counts were performed. Medication compliance surveys requesting the number of missed doses were also administered to patients and their physicians every month for 3 months.

Results:

Compliance assessments were as follows: patient report 80–100%, physician assessment less than 30–100%, pill counts 50–100%, and MEMS 9–100%. MEMS identified one patient's misunderstanding of zidovudine dosing. Three patients removed zidovudine from MEMS vials and placed the medication in a smaller vial for easy transport, thereby decreasing the usefulness of MEMS data.

Conclusions:

A combination of compliance assessment tools produces a more accurate representation of zidovudine dosing and facilitates identification of patient dosing errors. Use of multiple compliance tools, including MEMS data, during patient counseling may be an effective strategy for enhancing medication compliance.