• Karl A Lorenz, Cathy D Sherbourne, Lisa R Shugarman, Lisa V Rubenstein, Li Wen, Angela Cohen, Joy R Goebel, Emily Hagenmeier, Barbara Simon, Andy Lanto, and Steven M Asch.
• Veterans Administration Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Code 111-G, Los Angeles, CA 90064, USA. karl.lorenz@med.va.gov
• J Am Board Fam Med. 2009 May 1;22(3):291-8.

BackgroundAlthough many health care organizations require routine pain screening (eg, "5th vital sign") with the 0 to 10 numeric rating scale (NRS), its accuracy has been questioned; here we evaluated its accuracy and potential causes for error.MethodsWe randomly surveyed veterans and reviewed their charts after outpatient encounters at 2 hospitals and 6 affiliated community sites. Using correlation and receiver operating characteristic analysis, we compared the routinely measured "5th vital sign" (nurse-recorded NRS) with a research-administered NRS (research-recorded NRS) and the Brief Pain Inventory (BPI).ResultsDuring 528 encounters, nurse-recorded NRS and research-recorded NRS correlated moderately (r = 0.627), as did nurse-recorded NRS and BPI severity scales (r = 0.613 for pain during the last 24 hours and r = 0.588 for pain during the past week). Correlation with BPI interference was lower (r = 0.409). However, the research-recorded NRS correlated substantially with the BPI severity during the past 24 hours (r = 0.870) and BPI severity during the last week (r = 0.840). Receiver operating characteristic analysis showed similar results. Of the 98% of cases where a numeric score was recorded, 51% of patients reported their pain was rated qualitatively, rather than with a 0 to 10 scale, a practice associated with pain underestimation (chi2 = 64.04, P < .001).ConclusionThough moderately accurate, the outpatient "5th vital sign" is less accurate than under ideal circumstances. Personalizing assessment is a common clinical practice but may affect the performance of research tools such as the NRS adopted for routine use.

18 keywords...

hide…