Who refuses enrollment in cardiac clinical trials?

To evaluate the factors associated with refusal to participate in acute cardiac clinical trials.

Cardiac clinical trials in the acute setting pose a set of unique challenges to enrollment, such as the ability to obtain meaningful informed consent. In addition, it is unclear whether enrollment is associated with the sociodemographic characteristics (such as age, race and gender) of those being recruited. While policies have been instituted to enhance the representation of women and minorities in research, limited data exist on current enrollment patterns and reasons for refusal to participate in cardiac clinical trials.

184 patients approached to participate in one of 25 cardiac clinical trials at Duke University Medical Center from 11/01 to 05/04 were surveyed regarding reasons for or against participation in clinical trials to identify predictors of non-enrollment.

The mean age of the respondents was 61.6 years (SD 12.2), with 36% female and 32% non-white patients. There were no differences in refusal rates by age, gender or ethnicity. Higher acuity trials had higher refusal rates OR 3.6 (1.68-7.75) as well as not reading the informed consent form OR 2.99 (1.37-6.54). The main reasons people refused enrollment were due to inconvenience and not wanting to be experimented upon.

This study was cross-sectional and conducted at a single institution that conducts a high-volume of clinical research. In addition, a majority of the patients in the procedure/device studies were enrolled in one relatively low-risk cardiac catheterization laboratory trial with a low refusal rate. These attributes may limit the generalizability of the findings reported here.

Older persons, women and minorities are equally likely to agree to enroll in cardiac clinical trials as younger persons, men and non-minorities. Future efforts to increase the efficiency of recruitment should focus on improving convenience for participants in this acute setting and improving basic understanding of clinical trials.