Addressing the challenges of adherence.

Adherence to antiretroviral therapy is a crucial determinant of treatment success. Studies have unequivocally demonstrated the close association between adherence and plasma HIV RNA levels, CD4 cell counts, and mortality in patients with HIV infection and disease. Adherence levels of > or =95% are required to maintain virologic suppression. However, actual adherence rates are often far lower; most studies show that 40% to 60% of patients are <90% adherent. Adherence also tends to decrease over time. Patients offer a range of reasons for nonadherence, but the most frequently cited one is simply that they forget; other reasons include being away from home, being busy, or experiencing a change in daily routine. Additional barriers to adherence include psychiatric disorders, such as depression or substance use, uncertainty about the effectiveness of treatment and the consequences of poor adherence, regimen complexity, and treatment side effects. Several strategies can be employed in the effort to support patients' adherence, and all members of the multidisciplinary team should ideally employ these strategies in combination. Efforts should be made to educate and motivate patients, simplify treatment regimens and tailor them to individual lifestyles, prepare for and manage side effects, and address the concrete issues that may be a barrier to adherence. Recruiting an adherence monitor, providing memory aids to medication taking, and anticipating course corrections can also help patients achieve the adherence rates needed for successful treatment of HIV infection and disease.