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Updated: May 7, 2026
A Protocol of Manual Tests to Measure Sensation and Pain in Humans
Published on: December 19, 2016
Relative and absolute reliability of a vertical numerical pain rating scale supplemented with a faces pain scale
Li-ling Chuang1, Ching-yi Wu, Keh-chung Lin
1L. Chuang, PT, PhD, Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan, and Healthy Ageing Research Center, Chang Gung University, Taoyuan, Taiwan.
Background:
Pain is a serious adverse complication after stroke. The combination of a vertical numerical pain rating scale (NPRS) and a faces pain scale (FPS) has been advocated to measure pain after stroke.
Objective:
This study was conducted to investigate whether an NPRS supplemented with an FPS (NPRS-FPS) would show good test-retest reliability in people with stroke. The relative and absolute reliability of the NPRS-FPS were examined.
Design:
A test-retest design was used for this study.
Methods:
Fifty people (>3 months after stroke) participating in an outpatient occupational therapy program were recruited through medical centers to rate current pain intensity twice, at a 1-week interval, with the NPRS-FPS (on a scale from 0 to 10). The relative reliability of the NPRS-FPS was analyzed with the intraclass correlation coefficient for determining the degree of consistency and agreement between 2 measures. The standard error of measurement, the smallest real difference, and Bland-Altman limits of agreement were the absolute reliability indexes used to quantify measurement errors and determine systematic biases of repeated measurements.
Results:
The relative reliability of the NPRS-FPS was substantial (intraclass correlation coefficient=.82). The standard error of measurement and the smallest real difference at the 90% confidence interval of the NPRS-FPS were 0.81 and 1.87, respectively. The Bland-Altman analyses revealed no significant systematic bias between repeated measurements for the NPRS-FPS. The range of the limits of agreement for the NPRS-FPS was narrow (-2.50 to 1.90), indicating a high level of stability and little variation over time.
Limitations:
The pain intensity of the participants ranged from no pain to a moderate level of pain.
Conclusions:
These findings suggest that the NPRS-FPS is a reliable measure of pain in people with stroke, with good relative and absolute reliability.
