Perspectives on adherence and simplicity for HIV-infected patients on antiretroviral therapy - Self-report of the relative importance of multiple attributes of highly active Antiretroviral therapy (HAART) regimens in predicting adherence

Background: Adherence to highly active antiretroviral therapy (HAART) of 95% or greater seems to be required for successful treatment of HIV/AIDS. Efforts to simplify regimens to improve adherence are ongoing, including the advent of once-daily (QD) dosing regimens, which are presumed to be beneficial, although data regarding their overall impact on adherence are not yet available. Objective: To assess patient perceptions of the impact on adherence of 10 attributes of HAART, including QD dosing, and to compare 7 actual regimens based on patients' perceptions of their likelihood to promote adherence. Methods: Two hundred ninety-nine highly treatment-experienced patients with HIV/AIDS completed a questionnaire that evaluated perceptions of the impact on adherence of 10 HAART regimen attributes using a modified adaptive conjoint analysis. Patients' perceptions of the likelihood that they would adhere to 7 actual HAART regimens were scored on Likert scales. Results: Pill count, dosing frequency, and adverse events had the greatest impact on patients' perceived ability to adhere to antiretroviral medication regimens. QD was the preferred dosing frequency, but QD dosing regimens did not score better than other regimens. Among actual regimens, predicted adherence was highest for a twice-daily (BID) regimen with 2 pills daily,no dietary restrictions, and I prescription and copayment and lowest for a BID regimen with 13 pills daily, food requirements, and 3 prescriptions and copayments. Conclusions: All HAART regimen attributes studied were perceived to have an impact on adherence, but pill count, dosing frequency, and adverse events had the greatest perceived impact. These data are of potential importance to clinicians as they seek to structure HAART regimens to which their patients are most likely to adhere.