Background Pain in critically ill patients in the intensive care unit
(ICU) is common. However, pain assessment in critically ill
patients often is complicated because these patients are unable
to communicate effectively. Therefore, we designed a study (a)
to determine the inter-rater reliability of the Numerical Rating
Scale (NRS) and the Behavioral Pain Scale (BPS), (b) to
compare pain scores of different observers and the patient, and
(c) to compare NRS, BPS, and the Visual Analog Scale (VAS)
for measuring pain in patients in the ICU.