Surprisingly, a higher proportion of HIV patients in sub-Saharan Africa are following instructions when taking anti-HIV medications compared with those in North America, a new review says.

Antiretroviral therapy or ART has improved the lives of people infected with HIV. To reliably suppress the virus and prevent resistance, people may need to follow a complicated regimen with varying doses and dietary restrictions — all while dealing with a host of unpleasant side-effects of the medication.

There were concerns among medical authorities that poor African patients without formal education might not follow the regimen properly.

"This review contradicts a historical anticipation of poor adherence by Africans to antiretroviral regimens that was offered as a rationale to delay providing these therapies," said the study's lead author, Edward Mills, director of the Centre for International Health and Human Rights Studies in Toronto.

Mills and his colleagues looked at data involving about 17,000 HIV-infected patients in North America and about 12,000 in sub-Saharan Africa.

The study found that about 60 per cent of North Americans took their medications as directed, compared to slightly more than 75 per cent among sub-Saharan Africans, the team reports in Wednesday's issue of the Journal of the American Medical Association.

Access to affordable medications

In North America, barriers to following treatment regimes appear to include poor relationships between doctors and patients, untreated depression, and substance abuse, rather than poverty itself.

"Thinking that poverty was a risk factor for non-adherence was a mistake," said senior author Dr. David Bangsberg of San Francisco General Hospital Medical Center.

For Africa, the priority should be on ensuring patients take their medication by increasing access to affordable drugs, and distributing it to patients, the study's authors said.

Officials with the World Health Organization aim to increase access to antiretrovirals in sub-Saharan Africa. In Botswana for example, an estimated 56 per cent of HIV/AIDS patients urgently need therapy.

"Missed doses among the poor in resource-limited settings is less about neglected doses due to complex behavioural and social problems and is more about structural barriers to reliable medication access," Bangsberg said.

The study's authors note the complexity of the treatment regimen is potentially greater in North America, which should be taken into consideration when interpreting the data.

The research received funding from the Ontario and federal governments, as well as the National Institutes of Health in the U.S., and the Doris Duke Charitable Foundation.