Skip to main content

Advertisement

Table 2 Summary of key evidence to support the numeric rating scale (NRS) in pain

From: Response scale selection in adult pain measures: results from a literature review

Reference Study type, evidence type a, and grade b Article recommendations and rationale
Grotle et al. 2004 [41] Cross-sectional study, Direct, A The NRS showed statistically higher standardized response mean SRM when compared with the VAS. The VAS format is difficult for some patients and time-consuming to score. The NRS is easier to understand and quicker to score.
Gagliese et al. 2005 [16] Prospective study, Direct, A The NRS should be the first choice across age groups. Compared to the other scales, it had low error rates, high face validity, and high convergent, divergent, construct and criterion validity. Results suggest that use of the VAS should be discouraged, unless practice is provided to patients.
Jackson et al. 2006 [14] Instrument development and/or validation study, Direct, A Most participants preferred using an NRS to the continuous VAS. Some found numbers easier to use whereas others found the scale of pain intensity (referred to by authors as the SPIN) more helpful.
Ritter et al. 2006 [13] Cross-sectional study, Direct, A The NRS (with graphical component) is a valid measure and was as successful as the VAS in measuring the underlying pain variable. The NRS was easier to administer and code than the VAS.
Chanques et al. 2010 [18] Prospective study, Direct, A The NRS should be the tool of choice for the intensive care unit (ICU) setting, because it is the most feasible and discriminative self-report scale for measuring critically ill patients’ pain intensity.
Huang et al. 2012 [21] Instrument development and/or validation study, Direct, A The Faces scale and NRS were adapted and translated for a population of Swahili-speaking patients in western Kenya, and demonstrated the face validity, acceptability, and field-readiness of these scales through cognitive interviewing of hospitalized patients. In this population the Faces scale was preferred over the NRS.
Van Dijk et al. 2012 [42] Prospective study, Direct, A A lack of agreement is found between the patients and Acute Pain Nurses on what constitutes ‘bearable’ pain in relation to the reported NRS score. These findings suggest variable interpretation of scores on an NRS.
Chien et al. 2013 [17] Instrument development and/or validation study, Direct, A The NRS is potentially more sensitive to clinical changes in comparison to the VRS
Huang et al. 2013 [20] Prospective study, Direct, A The Faces scale and the NRS were easily understood and well accepted by participants and should be implemented for daily use in the inpatient setting in order to gauge patients’ pain and response to pain treatment.
Rothaug et al. 2013 [19] Prospective study, Direct, A Binary answer format was proven to be a practical alternative to the NRS format for a screening instrument, however may not be as sensitive to discriminate levels of pain intensity as compared to the NRS.
Gonzalez-Fernandez et al. 2014 [15] Cross-sectional study, Direct, A The NRS (referred to in the article as general Labeled Magnitude Scale; essentially a VAS with the addition of numbers along the scale) has the potential to replace the VAS in the measurement of pain intensity in the clinical setting. As a minimum it may serve as an important tool in the management of patients with chronic pain.
  1. a Direct evidence: Primary research that compares different response scales within study. Indirect evidence: Review or expert opinion based on empirical evidence
  2. b Grade Key: A) Primary research; compares different response scales within the study; B) Review or expert opinion; based on an empirical evidence base; C) Primary research; evaluates a single response scale type within the study; and D) Review or expert opinion, based on expert consensus, convention or historical experience