Pain Assessment Scales: An Overview for Pharmacists

JULY 14, 2016
Pain affects millions of Americans every year. Whether a patient’s pain is acute or chronic, or neuropathic or inflammatory, it’s undisputed that comprehensive and methodical assessment will guide pharmacists in selecting the most appropriate therapy.
Here’s an overview of some pain assessment scales:
Numeric Rating Scale (NRS)1
I recently volunteered on an interprofessional team providing health care to underserved populations in Connecticut. Several patients presented with some type of pain as their chief complaint.
Too often, I heard student clinicians ask, “On a scale of 1 to 10, how bad is your pain?” It’s essential to stress the NRS ranges from 0 to 10, with 0 being no pain at all and 10 being the worst pain imaginable.
The NRS is preferred by patients over other rating methods because of its comprehensibility.2 Therefore, the patient’s understanding of the scale and what’s being asked is key to reporting the most valid score.  
The NRS is perhaps the most convenient rating scale, requiring little time and allowing ease of verbal administration, including over the phone. 
Visual Analog Scale (VAS)3
The VAS is an instrument useful for pain assessment when patients can’t quantify their pain in distinct segments. It’s continuous and can be particularly valuable when assessing pain changes in one individual.
The scale is 10 cm in length and arbitrated on either end by terms like “no pain” and “very severe pain.” Patients mark where they feel their pain is, and the administering clinician measures its distance with a ruler, linking the result with a score.
The Colored Analog Scale is a similar, reliable self-reporting tool for assessment of acute pain in children.4
Wong-Baker FACES
Although initially devised for children, this pain scale is used in patients 3 years and older.  
Unlike the famous scene from an episode of Scrubs, providers don’t match the patient’s face to a face on the scale. Instead, they explain to the patient that the faces on the scale are happy because they have no pain, or sad because they have pain.

While pointing to each face, describe what it would be feeling, using phrases like “Face 0 is happy because he has no pain,” and progressing to “Face 5 is very sad because he has the worst pain possible.”

Jola Mehmeti, PharmD, MBA
Jola Mehmeti, PharmD, MBA
Jola Mehmeti is a 2018 PharmD graduate from the UConn School of Pharmacy. She is a CITI-certified researcher with investigative and work experience at a large tertiary care center in Hartford, Connecticut. Connect with her on LinkedIn or send a message to