Epidemiology as an essential tool for establishing prevention programs and evaluating their impact and outcome.

Emerging trends in health care place speech-language pathologists and audiologists on the threshold of role expansion. To include prevention efforts within this new role, clinicians need to ask about the determinants of communication disorders that are preventable within the general population or within sub-populations. In this article, epidemiology is presented as a tool for the primary prevention of a broad range of factors associated with increased rates of communication disorders. "Old" epidemiologic theory, based on populations, blends with the "new" epidemiologic approach emphasizing the contribution of individual behaviors to adverse health outcomes, to provide the working clinician with a framework from which to determine the direction prevention efforts must take. The PRECEDE-PROCEED model of program planning and evaluation (Green and Kreuter, 1991) is utilized in public health and holds potential for use by clinicians in preventing communication disorders. Application of communication disorders to the PRECEDE-PROCEED model is offered as an example of prevention planning.