Assessing medication adherence by pill count and electronic monitoring in the African American Study of Kidney Disease and hypertension (AASK) pilot study

Abstract

The Medication Event Monitoring System (MEMS), an electronic monitor which records the date and time of bottle cap openings, and pill counts were used to assess patterns of adherence for the primary antihypertensive drug in the African American Study of Kidney Disease and Hypertension Pilot Study (AASK). Blacks with hypertension and moderately reduced renal function were randomized to one of two levels of blood pressure control and to one of three antihypertensive drug regimens: primary therapy with a calcium channel blocker, an angiotension converting enzyme inhibitor, or a beta-blocker. Of the 94 participants in AASK, 91 had MEMS recordings and pill counts for 313 regularly scheduled monthly follow-up visits. The average length of follow-up was 4.6 months. An acceptable level of adherence by pill count was achieved if 80% to 100% of the prescribed pills were not returned to the clinic. Adherence by MEMS to a once-a-day drug dosing schedule was acceptable if 80% of the time intervals between MEMS openings were within 24 +/- 6 h. Acceptable adherence by pill count was observed at 68% of the follow-up visits; MEMS indicated nonadherence at 47% of those visits. Blood pressure was within goal in 50% of the participants who were adherent by both pill count and MEMS throughout their follow-up visits, and only 14% of the participants who were identified nonadherent by one or both methods. These findings suggest that electronic monitoring is a useful adjunct to pill counts in assessing adherence to antihypertensive drugs. Feedback of electronically collected information on dosing intervals to participants and staff may enhance adherence.

Comparison of Morisky Medication Adherence Scale with therapeutic drug monitoring in apparent treatment–resistant hypertension

“…15 Prescription fill rate may be more accurate than self-reported adherence, but it is time consuming to track, and information may not be accurate if the patients are not in an integrated health care system or fill prescriptions but do not take the dispensed medication. Pill count is also time-consuming and accurate in determining adherence only in 50%-70% of patients when compared with electronic pillbox 16,17 and 68% when compared with therapeutic drug monitoring. 18 More detailed self-reported questionnaires have been developed to detect medication non-adherence and avoid patients' tendency to report yes when they are simply asked if they have taken medications as prescribed.…”

The impact of medication regimen factors on adherence to chronic treatment: a review of literature

“…They also found that adherence to once-daily antihypertensive medication was higher (84%) than to thrice-daily dosing (59%) among 105 hypertensive patients. Similarly, Lee et al (1996) found that African American patients in the AASK cohort, being followed for hypertension and kidney disease, were more adherent to once per day than twice per day regimens measured by electronic monitoring (49% vs. 5% adherence, P < .001).…”

“…Moreover, based on the existing research, the number of concurrent medications may contribute to adherence or non-adherence. Three of the seven included studies in this area (Dunbar-Jacob et al 2003;Eisen et al 1990;Lee et al 1996) used electronic monitoring to measure adherence.…”

Adherence to treatment of osteoporosis: a need for study

“…At present, measurement of adherence in studies of osteoporosis relies mostly on pill counts and selfreporting [43]. Pill counts and self-reporting overestimate true compliance [44][45][46][47][48][49]. In addition, they provide no information on the patient's behaviour surrounding drug intake.…”