Assessing Pain in Osteoarthritis of the Knee

Peter L. Salgo, MD: Let’s talk about pain. People come in and say, “It hurts!” That’s not good enough. I was taught that there were 7 aspects of pain that you want to talk about—dimensions of pain. First of all, you want to assess how much it hurts. How do you go about assessing somebody’s pain or joint pain?

Richard Iorio, MD: Well, we do visual analog scales to ask them to put their pain into context. Those are rough methods of doing it.

Peter L. Salgo, MD: There are ADP [accelerated diagnostic protocol] scores, right? And, there’s the WOMAC index, which is the Western Ontario and McMaster Universities Arthritis Index…?

Paul Lachiewicz, MD: Right. At one of the clinics that I teach residents at, the nurse who puts the patient in the room will ask for their average daily pain score. But, most of us don’t use these on a regular day-to-day basis in the clinic. These are more of research tools for either intervention, such as injections, or other pharmaceutical agents or for after knee replacement surgery. The WOMAC is used very commonly.

Richard Iorio, MD: We actually use PROMs on a daily basis. We get PROMs on every patient that walks in the clinic.

Peter L. Salgo, MD: A PROM is…?

Richard Iorio, MD: A patient-reported outcome measure. There are disease-specific measures that look at arthritis. There are quality of life measures that look at how they’re doing overall, as opposed to just a disease-specific measure. We plot those scores on each visit, and we see if they’re doing better or worse than they were from the last time. We put it up on a screen, when the patient comes into the room. We show them how they’re doing. That helps offset the average daily pain score, because those can be affected by other aspects of a patient’s life. That has to be put into context.

Peter L. Salgo, MD: Walk me through this. A PROM sounds complicated.

Richard Iorio, MD: There are many questions.

Peter L. Salgo, MD: How many questions?

Richard Iorio, MD: There can be anywhere from 5 to 60 questions.

Peter L. Salgo, MD: So, if I were in your office and you wanted to do a PROM, how would you start?

Richard Iorio, MD: We send patients an e-mail a week or so before they come in. They can fill it out online. When they come into the office, if they haven’t filled it out, we give them an iPad to fill it out with. We used to do this with pen and paper. Those results are tabulated immediately, put into our electronic medical record, and plotted. It’s an interesting tool. I agree with Paul—it’s not defined whether it’s good or not, but we call it the sixth vital sign.

Peter L. Salgo, MD: Can you get a road map of PROMs online? “You can use one of these.”

Paul Lachiewicz, MD: I believe they’re available online.

Richard Iorio, MD: Some are commercially available. You actually have to pay for them. Others are publicly available.

Andrew Spitzer, MD: In osteoarthritis, and in a field like ours where we deal with pain, objectifying where patients are, at any given point, is a huge potential challenge. For instance, that’s one of the challenges with ADPs. ADPs are notoriously dependent upon how the patient is feeling within the last 24 hours. Because if you ask patients, “How have you been feeling for the last 3 weeks?” they remember that 2 days ago, they had excruciating pain that made it impossible for them to get through the day. So, that’s what they focus on.

So, ADPs are not necessarily that specific or sensitive. In turn, PROMs, I think, do a better job with that. One of the challenges in measuring pain is the fact that it is very much subjective. For me, I look to help patients to understand how it’s affecting their life. Rich mentioned the concept of a guy who starts out golfing 36 holes a day and walking those courses. Eventually, he ends up not being able to do that, even with a cart. So, using a patient as their own metric and finding out what’s important to them and asking them how that declines over time, to me, is a very important individualizing measure to determine the next step in treatment.

Peter L. Salgo, MD: So, the patient is in his or her own control?

Richard Iorio, MD: Well, we’ve seen this with the opioid epidemic. We have patients that say that their pain is 37/10. They can’t stand that pain. It’s horrible. “I need something more than what you’ve given me.” In the not so distant past, we treated that pain. A number of us treated it with opioids. We found that it’s probably not the way to go. They can overemphasize the pain. Ten out of 10 pain on an ADP is akin to being hit over the head with a baseball bat, right? It probably isn’t that severe. But, the patient’s reaction to the stimulus or to the pain may be that severe, and pain is very personal. When it’s you, you feel it’s severe.

Transcript edited for clarity.