Adherence to prescribed AIDS medications--that is, taking them consistently and properly--is key to healthy functioning (Catz, Kelly, Bogart, Benotsch, & McAuliffe, 2000). For example, nonadherence to one class of medications, protease inhibitors, is associated with rapid increase in HIV viral load and drug resistance: "To gain a durable suppression of viral replication, near-perfect adherence to dosage, timing, frequency, and food requirements is necessary" (Williams & Friedland, 1997, p.51). Yet on average, about half of those taking such medication do not take it consistently (Eldred, Wu, Chaisson, & Moore, 1998; Frick, Gal, Lane, & Sewell, 1998). This may be especially true of members of ethnic minorities, who were over 80 percent of women and 61 percent of men living with AIDS in 1999 (Centers for Disease Control and Prevention [CDC], 1999). In one study, 63 percent of European Americans who were eligible to take antiretroviral medications like zidovudine (AZT) took them, but only 48 percent of African A mericans did; 87 percent of European Americans took medicine to prevent pneumocystis pneumonia (PCP), but only 58 percent of African Americans did--results that could not be explained by income or access to insurance (Moore, Stanton, Gopalan, & Chaisson, 1994). Being a member of an ethnic minority group also has been associated with lack of adherence to AZT (Muma, Ross, Parcel, & Pollard, 1995) and with missed follow-up visits to check and get antiretroviral medication (Besch, Collins, Morse, & Simon, 1992).
ADHERENCE AND PERCEPTIONS OF ILLNESS OR MEDICATION
The Health Beliefs Model (Rosenstock, Strecher, & Becker, 1994) posited that people weigh the balance between barriers and benefits of a health-related behavior in deciding whether to perform a behavior or do so consistently. Perceiving a disease as more serious or considering oneself more susceptible to it predicts greater adherence to health behaviors. When a health behavior is viewed as costly or burdensome or as less rewarding than an alternative, adherence may decrease.
Factors affecting adherence to medication include perceptions of the disease and treatment regimen (the focus here), as well as features of the individual, patient-provider relationship, or clinical setting (Williams & Friedland, 1997). For example, people unable to tolerate side effects of a medication may be less likely to take it (Catz et al, 2000) or may prefer holistic medicine (Brown & Segal, 1996).Regimens of several medications taken several times a day may also lead people to forget taking medicine (Samet et al., 1992).
Notions of HIV
Subjective notions of illness, medication, or health care may affect adherence also. In putting new information into the context of our taken-for-granted cultural models of the world (Quinn & Holland, 1987), we may ignore aspects of new objects or situations that do not fit familiar categories. Flaskerud and Thompson (1991) found that some people construe HIV not in terms of a weakened immune system but in terms of germs-- something that could lead people to underestimate the seriousness of HIV/AIDS. Sweat and Levin (1995) found that 37 percent of their sample did not know that AIDS is caused by a virus; 15 percent did not know AIDS could cause death. Among lower-income African American women in the Midwest, only 29 percent knew that a person could have HIV without having AIDS, compared with 67 percent of a U.S. sample (Slonim-Nevo, Auslander, Munro, & Ozawa, 1994). Members of ethnic minority groups tend to be relatively uninformed about AIDS (Arrufo, Coverdale, & Vallbona, 1991), a difference from the genera l population that may correlate with relatively lower levels of education (Sweat & Levin). Also, callers of color to AIDS hotlines are especially likely to ask about symptoms and disease processes, suggesting that mass media information about HIV may not reach all groups equally well (Kalichman & Belcher, 1997). …