High adherence to HIV therapy saved healthcare dollars as well as lives in a South African cohort, researchers found.

Although medication costs were higher for patients who took their drugs as prescribed, overall average monthly costs for those with the best adherence were $63 a month lower than for those with the worst, according to Jean Nachega, MD, PhD, of Harvard School of Public Health, and colleagues.

The findings suggest that — even in resource-limited regions — programs designed to increase adherence to HIV therapy will be cost-effective, the researchers concluded in the Jan. 5 issue of Annals of Internal Medicine.

• Explain to interested patients that this study suggests that, in resource-limited countries, focusing on adherence to HIV therapy will save healthcare dollars.

Good adherence to highly active antiretroviral therapy (HAART) has been shown to reduce morbidity and mortality, they noted, but there has been no research on its effect on direct healthcare costs in places like South Africa.

To help fill the gap, they looked at a cohort of 6,833 adult patients enrolled in a private-sector disease management program in South Africa. To be eligible, patients had to have started antiretroviral therapy between Aug. 6, 2000 and April 30, 2006, and to have been in the program for at least six months.

Adherence was measured by direct pharmacy refills of HIV drugs, the researchers said, and the participants were divided into four quartiles, with quartile one having the lowest adherence and quartile four the highest.

Costs in the South African Rand were converted into U.S. dollars using the exchange rate in effect in April 2007, the researchers said.

Overall, average monthly costs were $370, including $32 for HIV drugs, $181 for inpatient care, $76 for consultations, $37 for investigations, and $53 for non-HIV medications, Nachega and colleagues found.

But costs were higher when adherence was lower. The average monthly costs were $313 for those in quartile four compared with $376 for those in quartile one.

Costs for inpatient care drove the difference, the researchers wrote. In the group with the best adherence, the average monthly cost for inpatient care was $92, compared with $190 for those with the worst adherence. The proportion of average monthly costs attributable to inpatient care rose from 29% for those with the best adherence to 51% for those with the worst.

The researchers cautioned that the results are from a private healthcare management program and may not reflect what happens in public HIV/AIDS programs. They added that indirect healthcare costs were not included.

Despite those limitations, “the obvious next step is to determine how best to allocate resources to promote adherence and realize these benefits,” according to David Bangsberg, MD, of Massachusetts General Hospital in Boston, and Steven Deeks, MD, of the University of California San Francisco.

Writing in an accompanying editorial, they suggested three broad areas for action:

• Reduction of structural, economic, and stigma-related barriers
• Interventions such as education and counseling, telephone calls, home visits from nurses, and directly observed therapy for all people on HIV treatment
• Interventions aimed at people with poor adherence because of such things as substance abuse or psychiatric illness