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Does HAART efficacy translate to effectiveness? Evidence for a trial effect
Prema Menezes1, William C Miller, David A Wohl
1Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
Plos One
|July 19, 2011
Summary
Clinical trial participation improved virologic suppression (VS) for early HIV therapy. However, this trial effect diminished in later HAART periods, showing no significant difference in VS between trial and non-trial patients.
Area of Science:
- Clinical Medicine
- Virology
- Public Health
Background:
- Patients in clinical trials may achieve better outcomes than those in routine care, a phenomenon known as the trial effect.
- The trial effect has not been previously evaluated in the context of Human Immunodeficiency Virus (HIV) clinical trials.
- Understanding this effect is crucial for interpreting clinical trial results and optimizing HIV treatment strategies.
Purpose of the Study:
- To investigate the existence and magnitude of a trial effect on virologic suppression (VS) in patients initiating Highly Active Antiretroviral Therapy (HAART).
- To compare VS rates between patients initiating HAART within a clinical trial versus those initiating therapy in routine clinical care.
- To assess whether the trial effect varied between early and current periods of HAART availability.
Main Methods:
- A comparative study design was employed, analyzing data from 738 patients initiating HAART.
- Virologic suppression (VS) was defined as plasma HIV RNA ≤ 400 copies/ml at six months post-HAART initiation.
- Risk ratios (RR) were calculated using binomial models, with analyses stratified by early (1996-99) and current (2000-06) HAART periods.
Main Results:
- Overall, 78% of patients achieved VS. Trial participants were 16% more likely to achieve VS (unadjusted RR 1.16).
- In the early HAART period, trial participants showed significantly higher VS rates (adjusted RR 1.33) compared to non-trial participants.
- In the current HAART period, no significant difference in VS was observed between trial and non-trial participants (adjusted RR 0.98).
Conclusions:
- A notable clinical trial effect was observed, enhancing HIV replication suppression in the early HAART era.
- This trial effect on virologic suppression was not evident in the more recent HAART period.
- Findings suggest that improvements in routine HIV care or changes in HAART regimens may have diminished the comparative advantage of clinical trial participation.
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