When patients tell you they’re feeling no pain, don’t take it at face value. The most frequently used screening assessment can often be inaccurate.
The numeric rating scale (NRS) asks patients to evaluate their pain as 0 (none) to 10 (worst possible). In a study involving 275 primary-care patients, the mean NRS score was 6. But almost a third of participants with pain severe enough to impair them in some way reported a score of 0.
Forty percent of the participants mentioned pain as a reason for their clinic visit. Yet, of those who listed pain as their main motivation, 21% gave their pain a 0 rating, as did 28% of those who listed pain as a secondary problem (J Gen
Intern Med. 2007;22:1453-1458).
“Accurate screening is important because pain symptoms, both serious and not-so-serious, are among the most common complaints in primary care,” says lead author Erin E. Krebs, MD, MPH, an assistant professor at the Indiana University School of Medicine in Indianapolis. The findings mean clinicians “should still ask questions about pain, even if the NRS score is 0.”
NRS screening is subjective, Dr. Krebs points out. “There is no single number that will apply to everyone, like a BP reading.”
Because it asks only about current pain, the assessment may be missing intermittent pains that vary in intensity. Language may pose a problem too. For example, the study mentions a patient who reported, “I feel great discomfort, but it’s different than pain.”
So, how does NRS rate with Dr. Krebs? “I’d give it a 5,” she says. “It has some value, but it is not the be-all and end-all of pain management.”