Margo McCaffery is a consultant in the nursing care of patients with pain, in Los Angeles. Chris Pasero is a pain management educator and consultant in Rocklin, CA.
Adapted from McCaffery M. Assessment: underlying complexities, misconceptions, and practical tools. In: McCaffery M, Pasero C. Pain: clinical manual. 2nd ed. St. Louis: Mosby; 1999. p. 35-102.