Determination of supply and requirements in physical therapy: some considerations and examples.

This article is an exploration of the specific application of need-based and demand-based models for assessing health personnel supply requirements to the field of physical therapy. Definitions and examples of these models are offered. Problems presented in the field of physical therapy in accurately defining need and demand are presented. Specific examples of current data collection at a variety of levels (professional association, private sector, state, and federal) are given.