Meta-analysis highlights wide variation in success of developing world HIV treatment

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A meta-analysis of studies of antiretroviral treatment in resource-limited settings shows large variations in the success of treatment. The findings are published in the July 15th edition of the journal Clinical Infectious Diseases.

The meta-analysis reviewed data from ten observational cohort studies carried out in African countries. Studies were identified by MEDLINE search and rejected if incomplete data had been published.

The meta-analysis showed that 57% of people followed had undetectable viral load at twelve months, with a 31% greater probability of undetectable viral load at this time point if medication had been provided free of charge.

Glossary

meta-analysis

When the statistical data from all studies which relate to a particular research question and conform to a pre-determined selection criteria are pooled and analysed together.

virologic response

Reduction in viral replication in response to treatment, especially achievement of an undetectable viral load.

 

disease progression

The worsening of a disease.

efficacy

How well something works (in a research study). See also ‘effectiveness’.

observational study

A study design in which patients receive routine clinical care and researchers record the outcome. Observational studies can provide useful information but are considered less reliable than experimental studies such as randomised controlled trials. Some examples of observational studies are cohort studies and case-control studies.

The analysis also found that initial CD4 cell count did not have a significant effect on treatment outcomes at month 12 (p = 0.761).

Although the authors conclude that “ART treatment programs in resource-poor settings have efficacy rates similar to those reported for developed countries”, this conclusion needs to be viewed with caution:

  • Four of the ten cohort studies reviewed in the meta-analysis had 101 or fewer participants. The largest had 743 participants. Only six cohorts had a twelve-month follow-up available.
  • Only five cohorts published data on survival and disease progression, over durations of six (0.85) to 24 months (0.86).
  • The authors chose a meta-analysis of 23 studies published in 2001 as the comparator on which to base the claim that developing world cohorts showed a similar rate of virologic response to developed world cohorts (Bartlett 2001). The meta-analysis does not discuss the choice of regimens used or the likely impact that choice of drugs may have had on success rates in various studies. In particular, it is misleading to compare the results of studies conducted in the late 1990s of patients using single protease inhibitor-based regimens with studies conducted in resource-limited settings which mainly used NNRTI-based regimens that are easier to adhere to and associated with fewer toxicities.
References

Ivers LC et al. Efficacy of antiretroviral therapy programs in resource-poor settings: a meta-analysis of the published literature. Clin Infect Dis 41 (online publication), 2005.