Improving adherence: Every little helps

Anna Poppa
Estimated reading time 2 minutes
This article is more than 24 years old.

According to new research from the University of California at San Francisco (UCSF), presented at last week’s 8th Annual Retroviruses Conference, people who experience problems adhering to HAART progress to AIDS more quickly than those with better adherence levels. Whilst previous research has clearly linked poor adherence with viral load rebound and treatment failure, this is the first study to associate adherence to HAART with disease progression.

The UCSF team prospectively measured adherence in a community-based sample of low-income individuals who had been taking three or more anti-HIV drugs for at least one month. Adherence was measured using MEMS, an electronic device which registers whenever a medication container is opened, and by conducting a series of unannounced home pill counts. Study endpoints were developing an opportunistic infection, or a CD4 count below 200 cells. (Both of these criteria constitute an AIDS diagnosis according to the US definition. In the UK and elsewhere in Europe, an opportunistic infection is AIDS-defining, but CD4 count cut-offs are not used to diagnose AIDS).

Adherence levels were stratified. Levels below 50% were considered low; between 51-90% was termed middle; and levels above 90% were considered high, though previous data have associated poor virological response with adherence levels below 95%. The UCSF team confirmed the relationship between viral load suppression and adherence levels, and also found adherence predicted disease progression.

Glossary

disease progression

The worsening of a disease.

sample

Studies aim to give information that will be applicable to a large group of people (e.g. adults with diagnosed HIV in the UK). Because it is impractical to conduct a study with such a large group, only a sub-group (a sample) takes part in a study. This isn’t a problem as long as the characteristics of the sample are similar to those of the wider group (e.g. in terms of age, gender, CD4 count and years since diagnosis).

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.

treatment failure

Inability of a medical therapy to achieve the desired results. 

community setting

In the language of healthcare, something that happens in a “community setting” or in “the community” occurs outside of a hospital.

Encouragingly, a 10% increase in the level of adherence reduced the risk of developing an OI, or progressing to a CD4 level below 200, by between 21-28%, which demonstrates the substantial health benefits to be gained through the provision of effective adherence support measures to people on HAART. Whilst adherence levels above 90% were deemed necessary for ongoing viral load suppression, the UCSF team concluded that lower levels of adherence, between 50-90%, may still delay disease progression over the short-term.

References

Bangsberg DR et al. Adherence to HAART predicts progression to AIDS. 8th Annual Retroviruses Conference, Chicago, abstract 483, 2001.

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