Risk factors for non improvement in HAART adherence identified in MACS

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A US study has found that there are specific factors associated with imperfect adherence to HAART, and with a failure to improve adherence. The study is published in the March 5th edition of AIDS.

Investigators from the Multicenter AIDS Cohort Study (MACS) wished to see which factors were associated with changes in levels of adherence and to determine if there are certain individuals whose adherence is consistently poor. MACS is an ongoing prospective cohort study involving over 5000 HIV-positive gay men in the USA.

At clinic visits between October 1998 and October 2000, a total of 486 men completed questionnaires enquiring about the level of their adherence over the previous four days. Adherence was classified as being 100% or less than 100%.

Glossary

p-value

The result of a statistical test which tells us whether the results of a study are likely to be due to chance and would not be confirmed if the study was repeated. All p-values are between 0 and 1; the most reliable studies have p-values very close to 0. A p-value of 0.001 means that there is a 1 in 1000 probability that the results are due to chance and do not reflect a real difference. A p-value of 0.05 means there is a 1 in 20 probability that the results are due to chance. When a p-value is 0.05 or below, the result is considered to be ‘statistically significant’. Confidence intervals give similar information to p-values but are easier to interpret. 

prospective study

A type of longitudinal study in which people join the study and information is then collected on them for several weeks, months or years. 

depression

A mental health problem causing long-lasting low mood that interferes with everyday life.

Visits were paired to determine if adherence changed over time. Potential determinants of adherence examined by the investigators included age, drug use, mental health, level of education and ethnicity.

The investigators found that the men in their study were generally highly adherent. Of the individuals who had 100% adherence at their first visit, 88.7% remained 100% adherent, and 11.3% reduced their adherence to less than 100%. Factors associated with a reduction in adherence to less than 100% included no recent outpatient appointment (p=0.004), being under 40 years of age (p=0.03), depression ((p=0.03), and lack of a college education (p=0.03). Missing appointments and depressive symptoms should alert doctors that a patient might be at higher risk of non-adherence, the investigators suggest. They add that the importance of adherence may need to be particularly stressed to individuals who are under 40 or who have less than a college education.

Of the 186 visit pairs with less than 100% adherence at the first visit, 28.5% remained less than 100% adherent at the later visit, with adherence improving to 100% in the remaining 71.5%. Not being African American (p

The investigators then looked at the 214 men reporting less than 100% adherence at one or more visit to see if poor adherence persisted over time and if there were any predictive factors. They found that 27.8% of men with one non-adherent visit reported less than 100% adherence at a subsequent visit, that 20.1% of men less than 100% adherent at two visits reported non-adherence at a subsequent visit; and that 46.3% of men non-adherent at three visits reported non-adherence at their fourth visit. This significantly showed (p

Being African American (p

The investigators conclude that “non-adherence to HAART medication was not a random event in the MACS. Participants reporting non-adherence were more likely to continue to be non-adherent.”

Further information on this website

Adherence - menu

Factsheets on adherence and anti-HIV therapy

Adherence - pdf of the 2003 edition of the booklet in the information for HIV-positive people series. To obtain a copy of the 2004 edition e-mail info@nam.org.uk.

References

Kleeberger CA et al. Changes in adherence to highly active antiretroviral therapy medications in the Multicenter AIDS Cohort Study. AIDS 18: 683 - 688, 2004.