The measurement of clinical pain.

Major problems in the measurement of clinical pain are created because of (1) its subjective nature, (2) a limited number of reliable and valid instruments that measure the experience, and (3) a multitude of clinical issues such as type of pain, cause, and patient sample characteristics. Instruments currently available measure intensity, behavioral and/or physiologic phenomena associated with pain, and multiple dimensions of the experience of clinical pain. Important factors the nurse must consider when selecting a measuring instrument are the various definitions of pain, the goals of the measurement problem, and the type of pain being measured. Additional factors are specific sample characteristics, ease of administration and scoring, and reliability and validity data. A careful and deliberative selection process should help provide useful and relevant information.