Effect of format on comprehension of adherence data in chronic disease: A cross-sectional study in HIV.
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%, <90%, <80% and <70% adherence) were presented in each format. Participants rated scenarios on adherence improvement needed. "Good understanding" was ≥ 4 of 5 scenarios correct. We calculated odds ratios for "good understanding" using logistic regression with percentage as the referent format.


RESULTS
124 participants were median age 48.5 years, 65% Black, 71% male. Understanding of all formats differed by education (all interaction p values<0.02). For ≤ 12 years education, odds ratios (OR) of understanding (95% CI) compared to percentage were: 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.


CONCLUSIONS
Calendars should be used to convey adherence information.
Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, PA, United States.
Anita
A
Lyons
Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, PA, United States.
Warren B
WB
Bilker
Department of Medicine (Infectious Diseases), Perelman School of Medicine, University of Pennsylvania, PA, United States.
Janet
J
Hines
Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, PA, United States; Department of Medicine (Infectious Diseases), Perelman School of Medicine, University of Pennsylvania, PA, United States; Department of Medicine (Infectious Diseases), Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States. Electronic address: grossr@mail.med.upenn.edu.
Robert
R
Gross
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D003142:Communication; D032882:Comprehension; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000523:psychology; D006801:Humans; D016015:Logistic Models; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010353:Patient Education as Topic; D063046:Patient Medication Knowledge
D019380:Anti-HIV Agents
HIV/AIDS; Health communication; Health numeracy; Medication adherence; Patient preferences