| Chapter 2: | Treating HIV/AIDS |
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(2005) study conducted in Canada, about 43% of individuals on HAART had an adherence level of less than 95%. In a study conducted in Spain, Carballo et al. (2004) found that 44% of the 235 participants on HAART had less than a 95% adherence level. Various scholars indicate different adherence rates in the United States, but average adherence is estimated at 70% (DiMatteo, Giordani, Lepper, & Crogham, 2002; Machtinger & Bangsberg, 2008). A few studies conducted in sub-Saharan Africa also reveal various HAART adherence levels. For example, Hardon et al. (2007) reviewed six quantitative studies in Africa and found that 65% to 99% individuals on HAART showed an adherence level of 95%. In another study of 514 HAART clients interviewed in Botswana, only 23% of individuals indicated a dosage adherence level of less than 95% (WHO, 2008b). The same study also found that as many as 79% of the 207 patients interviewed in Tanzania were below the critical adherence level (WHO, 2008b). Research further reveals that even when individuals do not miss a dose, they may fail to take medication at the exact appointed time (Williams & Friedland, 1997). For example, Melbourne et al. (1999) found that 50% of study participants with a 90% dosing adherence level took medication not at the exact time but within two or more hours after the appointed time. Failure to take medication at the exact time is almost as detrimental to public health as missing doses, especially in reference to the development of drug-resistant HIV. Following are public concerns of adherence failure.
Public Health Implications of Adherence Failure
Medication Adherence and Drug-Resistant HIV
There is a strong correlation between intermittent medication dosing and causation of drug-resistant HIV, which is a menace to public health. Drug-resistant HIV leads to treatment failure because it cannot respond to anti-HIV drugs, yet it may be transmissible. In explaining the formation of drug-resistant HIV, it is important to understand that the purpose of treating HIV with highly active antiretroviral drugs is not to cure but to suppress the virus or halt its replication (Machtinger & Bangsberg,