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Women shy away from trials


Women are less willing to participate in cardiovascular (CV) prevention trials than men, according to a report in the Archives of Internal Medicine.

Thisis despite women perceiving a greater risk of future heart attack andhaving lower levels of distrust than men, the study indicates.

Theauthors say efforts to clarify perceptions of risks and benefits oftrial participation by men and women may help to reduce the genderdisparity in willingness to participate (WTP).

Dr Eric Dingand team, of Harvard School of Public Health, Boston, USA, note thatthe under-representation of women in CV clinical trials remains anissue, despite equal inclusion of men and women in clinical trialsbeing a requirement specified by the US National Institutes of ClinicalHealth.

“Given the clear strong sex differences in thecause, disease prognosis, and treatment efficacy of CV conditions, afocus on sex-specific clinical research and understanding of sexdifferences in risk perceptions and trial participation is important,”the article explains.

The study involved 783 individuals at13 internal medicine and cardiology clinics. Participants were giventhe description of a hypothetical randomised, placebo-controlledclinical trial and asked whether they would enroll.

Severaldifferent trial scenarios with different side-effect risks, durations,sponsors, financial incentives, and conflicts of interest wereincluded. The participants rated their WTP on a five-point scale andwere also asked to give the reasons, or “mediating factors”, for theirdecision in terms of distrust, perceived 10-year risk of myocardialinfarction (MI) and perceived harm and benefits of joining the trial.

Theresults showed that men were 15% more likely than women to participatein trials, with a WTP score seen in 33.1% versus 28.7%, translatinginto a relative risk of 1.15.

After adjusting for mediatingfactors, the team found that gender differences in perceived risks andbenefits correlated with the difference in WTP.

Both menand women overestimated risks, but women perceived a greater risk fromthe trial than men (p=0.003) and an increased 10-year risk of MI(p=0.04). Meanwhile, men had greater levels of distrust than women(p<0.001).

Interestingly, disclosure of financialinvolvement of investigators increased WTP in women but decreased WTPin men, and distrust decreased WTP in men but not women.

Theresearchers conclude: “Evidence underscores the importance of sex indetermining clinical trial participation. However, overcoming sexdifferences in risk perceptions and WTP remains the duty and obligationof public health and medical professionals to equally include men andwomen in clinical trials to develop clinical treatments for preventionof all human diseases.”

Arch Intern Med 2007;167:905-12


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