Wong Baker

CLINICAL PRACTICE

Validation of the Wong-Baker FACES Pain
Rating Scale in Pediatric Emergency
Department Patients
Gregory Garra, DO, Adam J. Singer, MD, Breena R. Taira, MD, Jasmin Chohan, Hiran Cardoz,
Ernest Chisena, and Henry C. Thode Jr, PhD

Abstract
Objectives: The Wong-Baker FACES Pain Rating Scale (WBS), used in children to rate pain severity,
has been validated outside theemergency department (ED), mostly for chronic pain. The authors validated the WBS in children presenting to the ED with pain by identifying a corresponding mean value of
the visual analog scale (VAS) for each face of the WBS and determined the relationship between the
WBS and VAS. The hypothesis was that the pain severity ratings on the WBS would be highly correlated (Spearman’s rho > 0.80) withthose on a VAS.
Methods: This was a prospective, observational study of children ages 8–17 years with pain presenting
to a suburban, academic pediatric ED. Children rated their pain severity on a six-item ordinal faces scale
(WBS) from none to worst and a 100-mm VAS from least to most. Analysis of variance (ANOVA) was
used to compare mean VAS scores across the six ordinal categories. Spearman’scorrelation (q) was
used to measure agreement between the continuous and ordinal scales.
Results: A total of 120 patients were assessed: the median age was 13 years (interquartile range
[IQR] = 10–15 years), 50% were female, 78% were white, and six patients (5%) used a language other
than English at home. The most commonly specified locations of pain were extremity (37%), abdomen
(19%), andback ⁄ neck (11%). The mean VAS increased uniformly across WBS categories in increments
of about 17 mm. ANOVA demonstrated significant differences in mean VAS across face groups. Post
hoc testing demonstrated that each mean VAS was significantly different from every other mean VAS.
Agreement between the WBS and VAS was excellent (q = 0.90; 95% confidence interval [CI] = 0.86 to
0.93). There was noassociation between age, sex, or pain location with either pain score.
Conclusions: The VAS was found to have an excellent correlation in older children with acute pain in
the ED and had a uniformly increasing relationship with WBS. This finding has implications for research
on pain management using the WBS as an assessment tool.
ACADEMIC EMERGENCY MEDICINE 2010; 17:50–54 ª 2009 by the Societyfor Academic Emergency
Medicine
Keywords: pain measurement, child, adolescent

P

ain severity assessment, as required by The Joint
Commission,1 is intended to improve the quality
of pain management. Measures of a patient’s pain
must be reliable and accurately reflect the intensity of
pain being experienced. The practice of assessing pain as
‘‘the fifth vital sign’’ has become widespread,despite a
lack of published evidence demonstrating the accuracy
and effectiveness of screening strategies. Self-report of
From the Department of Emergency Medicine, Stony Brook
University, Stony Brook, NY.

Presented at the Society for Academic Emergency
Medicine annual meeting, New Orleans, LA, May 2009.
Received April 21, 2009; revisions received July 8 and July 19,
2009; accepted July20, 2009.
Address for correspondence and reprints: Gregory Garra, DO;
e-mail: ggarra@notes.cc.sunysb.edu.

50

ISSN 1069-6563
PII ISSN 1069-6563583

pain intensity is the preferred approach to pain assessment. There are several tools available to reliably assess
pain in children;2 however, there is no accepted criterion
standard.
The visual analog scale (VAS) is a common method
forthe quantification of pain severity. It is a continuous
outcome measure consisting of a 100-mm scale from 0
to 100 with low and high end points of no pain and
worst pain. The VAS is easy to administer and has been
validated in adults and older children. The VAS has
been shown to be a reliable and valid measure of acute
pain in the emergency department (ED).3
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