Pain assessment in the intensive care unit: development and psychometric testing of the nonverbal pain assessment tool.

BACKGROUND: Few standardized tools measure pain in nonverbal patients in the intensive care unit (ICU). Evidence exists that patient behaviors provide important information about pain in those unable to report their pain.

OBJECTIVE: The Nonverbal Pain Assessment Tool (NPAT), a behavioral pain assessment tool, was developed for the nonverbal adult patient in the ICU. Content and criterion validity and internal and interrater reliability were evaluated.

METHODS: The validity of NPAT was assessed against the patients' self-reports of pain. Interrater reliability was tested by 5 teams of 2 nurses assessing pain in nonverbal adult patients in 4 different ICUs.

RESULTS: The tool underwent 2 revisions and involved 270 patients. During the final evaluation, strong internal reliability (chronbach's α, .82; 95% confidence interval), moderately strong interrater reliability (concordance coefficient, .72; 95% confidence interval; and weighted κ statistic, .35), and moderately strong validity (concordance coefficient, .66; 95% confidence interval) were achieved.

CONCLUSION: The NPAT was found to possess moderately strong validity and strong internal and interrater reliability. It is easy to use, and provides a standard approach to assessing pain in the nonverbal adult patient.