Antihypertensive Medication-Taking Investigation of a Simple Regimen

Abstract

In search of strategies to improve compliance, we assessed medication-taking behavior among 19 ambulatory hypertensives, using both pill counts and electronic monitoring. The regimen consisted of one pill each day for < 6 3 weeks with return visits at 1 to 4 week intervals. The study population was 79% male, 68% white, and 16% black with mean ( ± SEM) age 58.4 ± 2.5 years. Only 51% of the intervisit intervals displayed ^ 8 0% of vial openings within the desirable range (24 ± 6 h). Pill counts detected only 2% of suboptimal interdosing intervals identified by electronic monitoring. Early changes in compliance correlated well with later changes (r = 0.83, Ρ = .002). A few of the subjects exhibited a large deviation from the prescription, uncorrectable with drugs having a long duration of action. We conclude that (a) pill counts tend to overestimate patients' compliance rates; (b) changes in medication-taking behavior early in therapy may predict subsequent compliance rates; and (c) prolonging drug action may compensate for some imperfect medication-taking behavior. Am J Hypertens 1993;6:586-592