Instruments currently available measure intensity, behavioural and/or physiological phenomena associated with pain, and multiple dimensions of the experience of clinical pain (Pautex & Gold 2006). Important factors that 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. Approaches to the measurement of pain include verbal and numeric self- rating scales, behavioural observation scales and physiological responses. The complex nature of the experience of painsuggests that measurements from these domains may not always show high concordance (Katz & Melzack 1999).