Adherence to antiretroviral therapy (ART) in older adults living with HIV/AIDS

Two decades ago, a person diagnosed with HIV infection confronted the very real possibility of death within a few years, if not sooner. The transformation of HIV from a terminal condition to a chronic, albeit manageable, ailment is largely the result of increasingly efficacious anti-retroviral therapy (ART). ART’s efficacy has manifested in the “graying” of the HIV epidemic. Indeed, by 2015, 50 percent of persons living with HIV/AIDS in the United States are expected to be ≥ 50 years of age and that number is expected to rise to 70 percent by 2020. Prevalence data show that in 2011, 45 percent of the 114,000 people living with HIV in New York City were already 50 years of age or older. During the past decade, there has been an average annual increase of 2 percent in the number of people ≥ 50 years of age in the U.S. living with HIV/AIDS (CDC, 2013). 

While the number of people living with HIV/AIDS who survive into their 50s, 60s and beyond is truly a success story, this pattern will only continue if our nation can link HIV-infected persons to adequate care, retain them in treatment and place them on antiretroviral therapy, with the goal of achieving viral suppression (Brooks, Buchacz, Gebo, & Mermin, 2012; Cahill & Valadéz, 2013). Unfortunately, of the almost 1.2 million people infected with HIV in the U.S., only one-fourth achieve viral suppression (see Figure 1). Viral suppression is contingent on adhering to ART regimens ≥ 90 percent of the time. This means that, for many people living with HIV/AIDS, they can skip or miss their HIV medications only once or twice a month. For many persons living with HIV/AIDS, this can be extremely challenging.

Figure 1: Treatment cascade for US HIV infected population (CDCData 2012). Percent of total US HIV population diagnosed, in care, on ART and achieving undetectable viral levels.

The potential challenges of consistent ART adherence in HIV-infected older adults are complex and ever-changing. Many HIV-infected older adults experience chronic health conditions, such as cardiovascular disease, cancer, osteoporosis, hypertension, kidney failure and liver disease, all of which can complicate their HIV treatment and efforts to adhere to ART regimens (Bhatia, Ryscavage, & Taiwo, 2012; Gebo & Justice, 2009; Guaraldi et al., 2011; Nokes et al., 2011; Petoumenos & Worm, 2011). Managing multiple comorbid conditions, including HIV, requires adherence to complex and burdensome pill regimens consisting of HIV-specific and non-HIV specific medications.  

Patterns and Predictors of ART Adherence in Older Adults

In spite of the physical, social and economic challenges that might decrease ART adherence in HIV-infected older adults, ART adherence in HIV-infected older adults appears to be quite good. Catz et al. (2001) found that, among 113 HIV-infected persons between the ages of 47 and 69, 71 percent self-reported consistent (i.e., 100 percent) ART adherence during the past week. Older adults who were more adherent were better educated, had better relationships with their physicians and used alcohol less frequently.   

Wutoh et al. (2001) conducted a cross-sectional investigation of 100 HIV-infected persons ≥ 50 years of age (mean=54.5 years) recruited from two large HIV clinics in Washington, D.C. (75 percent of whom were African-American). The sample’s mean self-reported adherence rate was 94 percent over the past seven days and 55 of the 100 participants reported 100 percent adherence during this time. Older adults who self-reported greater ART adherence also had lower viral loads as assessed through hematological testing at one of the clinics. 

Hinkin et al. (2004) prospectively assessed ART adherence in 148 HIV-infected persons between the ages of 25 and 69 over a one-month period using medication event monitoring systems caps. The mean ART adherence rate in participants ≥ 50 years of age was 87.5 percent, significantly greater than the rate of 78.3 percent observed in younger participants. HIV-infected persons ≥ 50 years of age were three times more likely than their younger counterparts to achieve adherence rates of 95 percent or greater. HIV-infected older adults who had difficulty adhering to ART regimens also demonstrated poorer neuropsychological functioning, particularly on measures of executive function and psychomotor speed.  

Johnson et al. (2009) assessed self-reported ART adherence in 244 HIV-infected persons ≥ 50 years of age in New York City and Columbus, Ohio, almost all of whom had been recruited through AIDS service organizations. Eighty-percent of participants self-reported adherence rates ≥ 95 percent. Unlike Hinken and colleagues (2004), ART adherence in this sample was unrelated to neuropsychological performance. Instead, HIV-infected older adults who were less adherent to ART regimens reported more negative affect, frequently brought about by poor social supports and greater reliance on maladaptive coping strategies. 

Finally, Bianco et al. (2011) assessed self-reported rates of adherence in 242 HIV-infected persons ≥ 50 years of age recruited though AIDS service organizations in 25 states. Contrary to the relatively high rates of adherence described in the studies above, only 49 percent of HIV-infected older adults reported consistent adherence to ART regimens. HIV-infected older adults who reported inconsistent ART adherence also reported more depressive symptoms, greater use of avoidance coping in response to taxing life stressors and received less social support from family members and friends.   

Higher rates of ART adherence in older adults living with HIV/AIDS are not unique to the United States. In research conducted in 10 HIV treatment programs in Burundi, Cameroon and the Democratic Republic of Congo, Newman et al. (2012) found that HIV-infected persons ≥ 50 years of age had 1.6 times the odds of being adherent to their HIV medications compared to their younger counterparts (i.e., persons 18 to 49 years of age). In Spain, Branas et al. (2008) compared rates of ART adherence between HIV-infected persons ≥ 65 years of age (n=30) to persons less than 65 (n=82). Although the difference was not statistically significant, a greater proportion of HIV-infected persons ≥ 65 (70.8 percent) reported ≥ 95 percent adherence compared to persons 65 years of age or younger (58.1 percent). 

Summary and Implication

Research almost always finds that ART adherence is greater in HIV-infected older adults than their younger counterparts. In fact, a recent meta-analysis concluded that older age reduced non-adherence by 27 percent in HIV-infected persons (Ghidei et al. 2013). The lone exception to this pattern is the Bianco et al. (2011) study, which found that less than one-half of HIV-infected persons ≥ 50 years of age were adherent to ART regimens in the past week. It should be noted that all participants in the Bianco et al. study were involved in an AIDS mental health randomized clinical trial and had mild, moderate or severe levels of depressive symptoms. As such, the mental health characteristics of this sample may have influenced their ART adherence efforts. 

If future research can determine why HIV-infected older adults are better able to adhere consistently to their medication regimens, perhaps this information can be shared with groups that experience greater difficulty with ART adherence (e.g., adolescents and young adults living with HIV/AIDS). In the meantime, age-contextualized interventions will be needed to facilitate the efforts of HIV-infected older adults who do experience difficulty adhering to life-extending antiretroviral therapy. 

References

Bhatia, R., Ryscavage, P., & Taiwo, B. (2012). Accelerated aging and human immunodeficiency virus infection: Emerging challenges of growing older in the era of successful antiretroviral therapy. Journal of Neurovirology, 18(4), 247–55. doi:10.1007/s13365-011-0073-y.

Bianco, J. A., Heckman, T. G., Sutton, M., Watakakosol, R., & Lovejoy, T. (2011). Predicting adherence to antiretroviral therapy in HIV-infected older adults: the moderating role of gender. AIDS and Behavior, 15(7), 1437–46. doi:10.1007/s10461-010-9756-2.

Brañas, F., Berenguer, J., Sánchez-Conde, M., López-Bernaldo de Quirós, J. C., Miralles, P., Cosín, J., & Serra, J. A. (2008). The eldest of older adults living with HIV: response and adherence to highly active antiretroviral therapy. The American Journal of Medicine, 121(9), 820–824. doi:10.1016/j.amjmed.2008.05.027.

Brooks, J. T., Buchacz, K., Gebo, K. A., & Mermin, J. (2012). HIV infection and older americans: The public health perspective. American Journal of Public Health, 102(8), 1516–26. doi:10.2105/AJPH.2012.300844.

Cahill, S., & Valadéz, R. (2013). Growing older with HIV/AIDS: New public health challenges. American Journal of Public Health, 103(3), e7–e15. doi:10.2105/AJPH.2012.301161.

Catz, S., Heckman, T.G., Kochman, A.R., & DiMarco, M. (2001). Rates and predictors of adherence to HIV medications among late middle-aged and older adults living with HIV/AIDS. Psychology, Health, and Medicine, 6, 47-58.

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Gebo, K. A., & Justice, A. (2009). HIV infection in the elderly. Current Infectious Disease Reports, 11(3), 246–254. doi:10.1007/s11908-009-0036-0.

Ghidei, L.  Simone, M. J., Salow, M. J., Zimmerman, K. M., Paquin, A. M., Skarf, L. M., … & Rudolph, J. L. (2013). Aging, antiretrovirals, and adherence: A meta-analysis of adherence among older IV-infected individuas. Drugs and Aging, August 2013. 

Guaraldi, G., Orlando, G., Zona, S., Menozzi, M., Carli, F., Garlassi, E.,  … & Palella, F.  (2011). Premature Age-Related Comorbidities Among HIV-Infected Persons Compared With the General Population. Clinical Infectious Diseases, 53(11), 1120–6. doi:10.1093/cid/cir627.

Hinkin C.H., Hardy, D.J., Mason, K.I., Castellon, S.A., Durvasula, R.S, Lam, M.N., & Stefaniak, M. (2004). Medication adherence in HIV-infected adults: Effect of patient age, cognitive staus, and substance use. AIDS, 18, Suppl 1, S19-S25.  

Johnson, C. J., Heckman, T. G., Hansen, N. B., Kochman, A., & Sikkema, K. J. (2009). Adherence to antiretroviral medication in older adults living with HIV/AIDS: a comparison of alternative models. AIDS Care, 21(5), 541–51. doi:10.1080/09540120802385611.

Nokes, K. M., Coleman, C. L., Hamilton, M. J., Corless, I. B., Sefcik, E., Kirksey, K. M.,  j… & Canaval, G. E. (2011). Age-related effects on symptom status and health-related quality of life in persons with HIV/AIDS. Applied Nursing Research : ANR, 24(1), 10–6. doi:10.1016/j.apnr.2009.03.002.

Newman, J., Iriondo-Perez, J., Hemingway-Foday, J., Freeman, A., Akam, W., Kalenga, L.,  … & Kiumbu, M.  (2012). Older adults accessing HIV care and treatment adherence in the IeDEA Central African Cohort. AIDS Research and Treatment, Volume 2012, Article ID 725713, doi:10.1155/2012/725713.  

Petoumenos, K., & Worm, S. W. (2011). HIV infection, aging and cardiovascular disease: epidemiology and prevention. Sexual Health, 8(4), 465–73. doi:10.1071/SH11020.

Wutoh, A.K., Brown, C.M., Kumoji, E.K.,  Daftary, M. S., Jones, T., Barnes, N. A., & Powell, N. J. (2001). Antiretroviral adherence and use of alternative therapies among older HIV-infected adults. Journal of the National Medical Association, 93, 243-250.

About the Author

Stephen Karpiak, PhD, is the senior director for research and evaluations at the AIDS Community Research Initiative of America in New York City and is on the faculty of New York University College of Nursing. Ten years ago he launched the largest most comprehensive research study of 1000 older adults with HIV entitled ROAH (Research on Older Adults with HIV). ROAH detailed the psychosocial characteristic of this aging population. ROAH has been modified for use in other U.S. cities, in the UK and recently in Africa.