Effect of format on comprehension of adherence data in chronic disease: A cross-sectional study in HIV.

Abstract Objective To determine which formats communicate medication adherence effectively to patients. Methods HIV-infected adults on antiretrovirals viewed examples of refill data in 5 formats: (1) percentage of doses, (2) number of days late to refill (“days late”), (3) calendar of days with/without medications, (4) pie chart of days with/without medications, and (5) letter grade. Five scenarios (>95%, 90–95%, Results 124 participants were median age 48.5 years, 65% Black, 71% male. Understanding of all formats differed by education (all interaction p values  days late 3.3 (2.3–4.7), calendar 3.1 (2.2–4.3) pie chart 2.0 (1.4–2.7), and letter grade 1.8 (1.3–2.5). For >12 years education, ORs were: days late 1.3 (0.9–2.0), calendar 2.4 (1.5–3.8), pie chart 2.9 (1.8–4.6), and letter grade 1.7 (1.1–2.6). Calendar plot was most preferred. Conclusions Adherence percentage was the least understood format regardless of education. Practice implications Calendars should be used to convey adherence information.