3.3.1 Demographic and socioeconomic factors
Although the literature consistently demonstrates that demographic characteristics are not strong predictors of adherence, some correlates of adherence are described below together with socioeconomic factors.
Age may influence adherence. Studies have found that, with the exception of the most elderly, adherence increases with age. In two studies associated with ART adherence, sub-optimal adherence showed a positive correlation with being younger (Jones et al., 1999).
3.3.3 Level of education
A lower level of general education and poorer literacy may impact negatively on some patients' ability to adhere, while a higher level of education has a positive impact (Catz et al., 1999).
3.3.4 Financial constraints
Studies conducted in Africa reveal that the cost of medication is one of the most significant barriers to treatment adherence. In Botswana, Weiser et al. (2003) report adherence difficulties related to the financial demands of therapy and an inability to afford medicines for varying periods. They note that 70% of patients claimed that the cost of ARVs posed a problem for them, and 44% of patients believed that the cost impeded their ability to adhere to treatment. Similarly, over one-half of health care providers (56%) believed that financial problems often or always impeded adherence to ART. The extent to which financial difficulties played a key role in sub-optimal adherence is also reported in study findings in Uganda for patients receiving non-subsidized therapy (Byakika-Tusiime et al., 2003). Medications and clinic visits cost money and may stretch an already meagre budget. In resource-poor countries many people live below the poverty line and there is often no medical insurance or disability pension for people living with HIV (PLWHIV) (Katabira, 2002).
3.3.5 Social support
Living alone and a lack of support have been associated with an increase in sub-optimal adherence (Williams and Friedland, 1997), and social isolation is predictive of sub-optimal adherence. Not living alone, having a partner, social or family support, peer interaction, and better physical interactions and relationships are characteristics of patients who achieve optimal adherence (Motashari et al., 1998).