Order and disorder in medicine and occupational therapy.

Professional practice is based on knowledge of order, disorder, and change. The meaning of these concepts in medicine and in occupational therapy is compared to clarify the differences in orientation between the two disciplines. The negative influence of the biomedical model on occupational therapy theory and practice is illustrated. The development of a taxonomy of levels of performance in occupation to serve as a basis for referral to occupational therapy and for theory building is suggested.