A Systematic Review and Synthesis of Psychometric Properties of the Numeric Pain Rating Scale and the Visual Analog Scale for Use in People With Neck Pain

We report a systematic search and synthesis of evidence about the measurement properties of the Numeric Pain Rating Scale and the Visual Analog Scale as patient-reported outcome measures in neck pain research. CINAHL, Embase, PsychInfo and MedLine databases were searched to identify studies evaluating the psychometric properties of the Numeric Pain Rating Scale and the Visual Analog Scale used in samples of which >50% of participants were people with neck pain. Quality and consistency of findings were synthesized to arrive at recommendations. 46 manuscripts were included. High-to-moderate quality evidence of good to excellent (0.58 to 0.93) test-retest reliability over an interval of seven hours to four weeks. Moderate evidence of clinically important difference of 1.5 to 2.5 points, with minimum detectable change of 2.6 to 4.1 points. Moderate evidence of a moderate association (r=0.48 to 0.54) between the Numeric Pain Rating Scale and the Visual Analog Scale and the Neck Disability Index, with findings from other patient-reported outcome measures indicating stronger associations with physical performance than emotional status. There is limited research addressing the extent that these measures reflect important patient outcomes. It is clear Numeric Pain Rating Scale and the Visual Analog Scale ratings are feasible to implement, provide reliable scores and relate to multi-item patient-reported outcome measures. Responsiveness (meaningful change) of the scales and interpretation of change scores requires further refinement. The Numeric Pain Rating Scale can be a useful single item assessment complimenting more comprehensive multi-item patient-reported outcome measures in neck pain research and practice.