Numeric Pain Rating Scale

Original Editor - Venus Pagare

Top Contributors - Venus Pagare, Tomer Yona, Kim Jackson, Evan Thomas, Vanessa Rhule, Claire Knott, Lauren Lopez, Lucinda hampton, 127.0.0.1, WikiSysop and Melissa Coetsee  

Purpose

The NRS for pain is a unidimensional measure of pain intensity in adults, including those with chronic pain due to rheumatic diseases.

Content

The NRS is a segmented numeric version of the visual analog scale (VAS) in which a respondent selects a whole number (0–10 integers) that best reflects the intensity of their pain. The common format is a horizontal bar or line. Similar to the pain VAS, the NRS is anchored by terms describing pain severity extremes.

Number of Items

Although various iterations exist, the most commonly used is the 11-item NRS.

Response Options/Scale

An 11-point numeric scale (NRS 11) with 0 representing one pain extreme (e.g., “no pain”) and 10 representing the other pain extreme (e.g., “pain as bad as you can imagine” and “worst pain imaginable”).

Recall period for items

Varies, but most commonly respondents are asked to report pain intensity “in the last 24 hours” or average pain intensity.

Obtaining the Scale

Available from the web site: http://www.partnersagainstpain.com/printouts/A7012AS2.pdf.

Administration

The NRS can be adminis-tered verbally (therefore also by telephone) or graphically for self-completion. The respondent is asked to indicate
the numeric value on the segmented scale that best describes their pain intensity.

Scoring and Interpretation

The number that the respondent indicates on the scale to rate their pain intensity is recorded. Scores range from 0–10. Higher scores indicate greater pain intensity.

Merits and Demerits

• The pain NRS takes <1 minute to complete.
• The pain NRS is easy to administer and score.
• Minimal language translation difficulties supports the use of the NRS across cultures and languages

Psychometric Information

Development

To improve discrimination for detecting relatively small changes, an NRS comprised of numbers along a scale was used in a population of 100
patients with a variety of rheumatic diseases. Variations in pain descriptors used as anchors for end points on the pain NRS have been reported in the literature. However, the methodology used to develop these various anchor terms is unknown.

Acceptability

Chronic pain patients prefer the NRS over other measures of pain intensity, including the pain VAS, due to comprehensibility and ease of completion. However, focus groups of patients with chronic back pain and symptomatic hip and knee osteoarthritis (OA) have found that the pain NRS is inadequate in capturing the complexity and idiosyncratic nature of the pain expe-rience or improvements due to symptom fluctuations.

Reliability.

High test–retest reliability has been ob-served in both literate and illiterate patients with rheumatoid arthritis (r �0.96 and 0.95, respectively) before and after medical consultation.

Validity

For construct validity, the NRS was shown to be highly correlated to the VAS in patients with rheumatic and other chronic pain conditions (pain�6 months): cor-relations range from 0.86 to 0.95.

Ability to detect change.
In clinical trials of pregabalin for diabetic neuropathy, postherpetic neuralgia, chronic low back pain, fibromyalgia, and OA, analyses of the relationships between changes in pain NRS scores and patient
reports of overall improvement, measured using a stan-dard 7-point patient global impression of change, demon-strated a reduction of 2 points, or 30%, on the pain NRS scores to be clinically important. Similar results were found in low back pain patients when changes in pain
NRS scores were compared to patient improvements in pain after physical therapy, using a 15-point Global Rating of Change scale