Substance use health services research.

This report provides an introduction to substance use health services research based upon the conceptual model of Andersen and Aday and demonstrates how the subsequent papers provide important insights into issues raised in this conceptual model. These issues include access and barriers to health care, needs for care, health care utilization, outcomes of care, and costs of care. We show how these issues are also expanded beyond more traditional definitions. We conclude by indicating some broad areas for further research.