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Behavior on Trial

Jon Reinfurt

Behavior on Trial (continued)

When faced with this challenge, some investigators and bioethicists invoke the “real world” or the notion of “usual care.” In theory, the control arm of a trial represents the local standard of care in the setting. “What is usual care in some developing countries? Nada,” says Celentano, ScD ’77, MHS ’75. “You want to do what’s right for the community, but these ethical imperatives make the science incredibly hard to do.”

Community trials of behavior change interventions are expensive and take years. With full-monty prevention packages, the results are sometimes unimpressive. “And then the basic science folks say, ‘See, behavior change doesn’t work,’” Celentano says.

Sugarman, MD, MPH, MA, who chairs the Ethics Working Group of the HIV Prevention Trials Network, cites ethical and pragmatic reasons for examining carefully the standard of prevention. Ethically, it might be irresponsible to introduce a prevention package that cannot be sustained or implemented locally after the trial has finished. Practically, he argues, it’s important to remember that just because something works in one setting doesn’t mean it will work in another setting. For example, while an antiviral drug may be useful in preventing HIV among men who have sex with men, it remains unclear whether the same drug will be effective in preventing heterosexual transmission. To include that in a prevention package among heterosexuals might be premature and presumptuous.

Yet another challenge is the adding on of new interventions mid-trial as they are shown to be effective—to maximize benefits to participants. “I worry that the ethics discussion got ahead of itself by not asking what we need to know before adding new interventions. You can’t always change a study design on the fly,” says Merritt.

“Heaping on interventions in the prevention package isn’t necessarily the right thing to do,” says Sugarman.“You need to make sure there’s an explicit reason for doing so and that there is reason to assume that more will necessarily be better.”

The Gold Standard

For the last 30 years, RCTs have been considered the gold standard in evaluating HIV preventive interventions. The RCT has been linked in our hearts and minds with the term “evidence-based medicine,” and thus, argues Steve Goodman, a core faculty member in both the School’s Center for Clinical Trials and the Berman Institute of Bioethics, the gauntlet has been thrown down. To be taken seriously, an intervention must prove itself in a randomized trial.

In biomedical interventions such as male circumcision, designing an RCT is challenging enough. In the circumcision trials, participants consented to take part in the trial without knowing if they would be assigned to the intervention arm (circumcision) or the control arm (circumcision only after it was shown effective). Because the assignments are randomized to reduce bias, neither the participant nor the provider has any say in who gets what done. “One could argue that the reason clinical trials are a new entry in the tools of medical investigation is that doctors and patients couldn’t countenance the notion of randomization,” says Goodman, a professor in Epidemiology. “There’s an ethical calculus in every trial.”

But at least with a biomedical intervention—circumcision, for example—investigators can more or less control both arms. One group gets the circumcision; the other doesn’t. It’s either yes or no, cut or uncut. No gray area.

Behavior change interventions, on the other hand, create gray areas. Take the example of a mass media campaign that encourages people to have fewer sexual partners. The first complication is that there’s no way to control who sees a billboard or hears a radio commercial; diffusion is inevitable.

Deanna Kerrigan, who directs a USAID R2P (Research to Prevention) project to evaluate HIV/AIDS intervention programs under way in several African countries, finds diffusion to be one of the many challenges in evaluating these types of interventions. “With a pill, you know—yes or no,” she says. “When you deal with a mass media campaign, it’s impossible to say this group got it, this group didn’t.”


This forum is closed

    FREETOWN, SIERRA LEONE 05/12/2011 12:21:10 PM

    These findings are really great, but how do we relate the paradox with the objective of the intervention, as to me, it seems it will mitigate the wider goal. Kind regards, JAMES

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