Botswana's ART programme achieves good results

Mortality rates down, CD4 counts up, but loss to follow-up a concern
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Botswana’s antiretroviral treatment (ART) programme has achieved good results, analysis of nine years of data published in The Lancet Global Health shows. The overall mortality rate was 8%. Mortality rates were highest during the first year after starting ART and fell dramatically during subsequent years of therapy.

The research was undertaken by an international team of investigators, who argue that Botswana’s ART programme “successfully reduced mortality among patients with AIDS to levels much the same as those reported in other low-income or middle-income countries, and continued to improve this low mortality rate over the study period”. Other recent research showed the “astounding” success of South Africa’s ART programme.

In 2002, Botswana became the first country in sub-Saharan Africa to introduce a national ART programme. Called Masa, the programme provides free and universal therapy according to national guidelines. The CD4 count threshold for starting ART was initially 200 cells/mm3. This was increased to 250 cells/mm3 in 2008 and further increased to 350 cells/mm3 in 2013. By November 2012, over 200,000 people were receiving ART thanks to Masa.

Glossary

person years

In a study “100 person years of follow-up” could mean that information was collected on 100 people for one year, or on 50 people for two years each, or on ten people over ten years. In practice, each person’s duration of follow-up is likely to be different.

loss to follow up

In a research study, participants who drop out before the end of the study. In routine clinical care, patients who do not attend medical appointments and who cannot be contacted.

AIDS defining condition

Any HIV-related illness included in the list of diagnostic criteria for AIDS, which in the presence of HIV infection result in an AIDS diagnosis. They include opportunistic infections and cancers that are life-threatening in a person with HIV.

middle income countries

The World Bank classifies countries according to their income: low, lower-middle, upper-middle and high. There are around 50 lower-middle income countries (mostly in Africa and Asia) and around 60 upper-middle income countries (in Africa, Eastern Europe, Asia, Latin America and the Caribbean).

Investigators used the electronic records of patients who started ART between 2002 and 2010 to assess mortality rates, loss to follow-up, and CD4 count trends.

Their study population comprised 126,263 adult patients. Approximately two-thirds (63%) were women and the median baseline CD4 cell count was 151 cells/mm3. However, 13% of patients had a CD4 count below 50 cells/mm3 when they started therapy and 36% had a count between 50 and 150 cells/mm3.

Median baseline CD4 count increased in each year of analysis from 101 cells/mm3 in 2002 to 191 cells/mm3 in 2010. Overall, patients’ CD4 counts increased significantly during the first 24 weeks of ART, and a count of 350 cells/mm3 was achieved an average of 24 months after treatment initiation.

A total of 10,230 (8%) deaths were documented during the nine years of the study. The overall mortality rate was 2.71 deaths per 100 person-years. Mortality was highest during the first three months of treatment (12.8 deaths per 100 person-years) but fell to 3.46 deaths per 100 person-years by month six of therapy. The mortality rate in the second year of ART was 1.16 death per 100 person-years. Mortality then steadily declined over the next seven years of follow-up to 0.17 deaths per 100 person-years.

In 2002, the first year of the programme, 29% of patients who enrolled died. But in 2009, only 3% of those entering the programme died. The proportion of the total enrolled population dying per year fell from 63% in 2002 to 0.8% in 2009.

A total of 15,270 patients were lost to follow-up, with approximately a fifth of patients dropping out of care in the first year of therapy. “Loss to follow-up, or lack of electronic documentation, seems to be an important issue to be addressed,” comment the investigators.

They assumed that 60% of lost-to-follow-up patients had died, increasing the overall mortality rate from 8% to between 11 and 13%.

Despite this, the authors believe that Botswana’s ART programme has been a success, and conclude that, “as treatment improves and patients live longer, the national ART programme will need to deal with ART-related toxicities and non-AIDS defining disorders."

The author of an accompanying editorial praised the study as “a welcome addition to the scientific literature on ART programmes”.

References

Farahani M et al. Outcomes of the Botswana national HIV/AIDS treatment programme from 2002 to 2010: a longitudinal analysis. The Lancet Global Health, online edition, dx.doi.org/10.1016/s2214-109x(13)70149-9, 2013.

Stover J Lesson from Botswana’s HIV/AIDS treatment programme. The Lancet Global Health, online edition, dx.doi.org/10.1016/s2214-109x(13)70175-x, 2013.