The purpose of this study was to examine the predisposing, enabling, and health status characteristics of adult herb users in the US; their use of other health services and medications both conventional and complementary; and the reasons for and perceived benefit of using herbs. This study is unique in combining the examination of health conditions individuals seek to treat with herbs, their perceived benefit of such treatment, and the concomitant use of conventional and other CAM health resources.

Analysis was conducted using both logistic regression and structural equation modeling (SEM). Findings of this study differ from the findings concerning herb use in previous studies. The final SEM analysis of this study found the following characteristics to be causally related to the use of herbs: male gender, Hispanic ethnicity; Black, Asian, or being of multiple races; elementary school education, low income, having no source of care or no regular source of care, and inability to afford prescription drugs. Herb users were less likely to use conventional care than non-users, and more likely to have used other CAM modalities. Conditions causally associated with use included multiple sclerosis and Parkinson's disease, prostate and menopausal problems, and chronic bronchitis. Characteristics associated with use of herbs to treat a health condition were: Hispanic ethnicity, Black, Asian, or being of multiple races; elementary school education, low income, "other place" as a usual source of care, and inability to afford mental health care. Conditions causally associated with use to treat were similar to use, and use of CAM was more likely than for non-treaters.

Individuals of Hispanic ethnicity and of minority races were more likely to consider herbs important to health and well-being and to perceive them as having helped the most bothersome conditions treated; as were individuals who used herbs because they thought medical care to be ineffective or too expensive. Lacking a regular source of medical care or not having one was correlated with the perceived importance of taking herbs, while having a conventional practitioner recommend trying herbs and a change in health status from the prior year were correlated with perceived helpfulness.