OBJECTIVE: To determine and quantify the unique characteristics of clinical trial participants in comparison to the general patient population. METHODS: Data were obtained from the U.S. National Health and Wellness Survey, an annual, nationally representative, Internet-based study of the health care attitudes and behaviors of non-institutionalized adults age 18+. The sample for analysis included 18,419 respondents who reported a diagnosis of hypertension, high cholesterol, or diabetes. Respondents reported ever participating in a clinical drug trial. They also provided information on demographics, healthcare attitudes, health habits, quality of life measured by the SF-8, and healthcare resource use in the past six months. RESULTS: Among respondents diagnosed with hypertension, high cholesterol, or diabetes, 7% (n=1333) have participated in a clinical drug trial. Clinical trial participants significantly differ from the general patient population in many key characteristics. Clinical trial participants are significantly older (mean age 60.5 versus 55.1, p<0.001) and more educated (college graduates 43% versus 36%, p<0.001). They experience worse physical well-being (sf-8 physical component summary score 43.1 versus 45.3, p<0.001), though are more likely to maintain a healthy diet (50% versus 46%, p=0.002) and less likely to smoke (18% versus 23%, p<0.001). Clinical trial participants are more willing to use alternative therapy such as acupuncture (49% versus 43%, p<0.001) and more likely to visit an alternative provider (32% versus 24%, p<0.001). They are also more likely to visit a traditional provider (96% versus 92%, p<0.001) and do so with greater frequency (visits 7.2 versus 5.6, p<0.001) than the general patient population. CONCLUSION: Clinical trial participants are unique individuals who differ from those in the general patient population. Therefore, the treatment experiences of clinical trial participants may not always be predictive of the treatment experiences of the general patient population.