Asking knee osteoarthritis patients a simple question – do you have difficulty climbing stairs? – may predict the risk of future functional limitation, according to research presented at the annual meeting of the American College of Rheumatology. Finding out that the patient has difficulty also opens avenues for further evaluation and intervention, said Jason Jakiela, a PhD candidate at the University of Delaware, Newark, who led the study. “We like to view it as a kind of yellow flag,” Jakiela said in an interview.
Another expert agreed. “I think this is useful for clinical rheumatologists,” said C. Kent Kwoh, MD, professor of medicine and medical imaging at the University of Arizona, Tucson, and director of the University of Arizona Arthritis Center. He commented on the study findings but was not involved in the study. Another common question asked of OA patients, about pain, may not be as useful as asking about difficulty climbing stairs, he said. “Their pain level can go up and down and can be quite varied.”
Osteoarthritis affects more than 32.5 million adults, according to the CDC, and the knee is a common site.
Study Details, Results
Jakiela and his team, including Daniel White, PT, ScD, MSC, associate professor of physical therapy at the University of Delaware, Newark, used data from the Osteoarthritis Initiative (OAI). They assessed stair climbing difficulty at baseline with the question: Does your health now limit you in climbing several flights of stairs? Respondents could answer that they were limited a lot, a little, or not at all.
The researchers evaluated functional limitation using two measures: Walking speed and Western Ontario and McMaster Universities Osteoarthritis Index physical function (WOMAC-PF) scores. A walking speed of < 1.22 m/s over 20 meters, the speed needed to safely cross a timed intersection, represented poor function. A WOMAC-PF score of 28/68 or more was also used to define low functioning.
The analyses included only people free of functional limitations at baseline. Each measure was conducted at the start and then at 12, 24, 36, 48, 72, and 96 months’ follow-up visits.
While 2,952 participants (mean age 60.1, 54% female, mean body mass index 27.9) were in the walking speed sample, 3,983 participants (mean age 61.2, 57% female, mean BMI 28.2) were in the WOMAC-PF sample.
When compared with people who had no limitations, those limited a little had a 47% greater risk of gait speed functional limitation and those limited a lot had a 61% greater risk at follow-up. There was a 70% greater risk for functional limitation defined by WOMAC-PF score at follow-up among people who were limited a little in stair climbing when compared with those not limited at all, and people with a lot of limitations had 161% greater risk. Slow gait speed has been linked with mortality.
Over the 8-year follow-up, 973 in the walking speed sample and 578 in the WOMAC-PF sample developed functional limitation.
Starting the Conversation
The question about stair climbing difficulty is a good “jumping-off point,” Jakiela said. “It opens up a line of questioning.” With knee OA, stair climbing difficulty is often the first reported limitation. That difficulty could capture a variety of issues, he said. Patients could be struggling with strength issues, cardiovascular problems, or balance deficits, for instance.
It signals there may be a trajectory of slow decline coming in this patient, Jakiela said.
“It’s a signal that something is not right,” White said in an interview. “We don’t know what is wrong.” While questions about stairs have routinely been asked of OA patients, the study findings suggest the answer to the question about having difficulty could help predict a patient’s future course, he said.
After patients reported a little or a lot of difficulty with stair climbing, the average time to reach functional limitation status was about 3 years, Jakiela said. That gives health care providers time to ask more questions about the patient’s condition and potentially intervene, depending on the details of the difficulty. If it’s a balance issue, physical therapy might help, for example.
While gait speed is a tried-and-true indication, collecting answers about stair climbing difficulty is easier and quicker for clinicians than assessing gait speed, which requires more time as well as office space, Jakiela said. It’s also intuitive for the patients to recall, the researchers said.
More Practical Takeaways
Finding out whether functional limitation is likely, based on the stair question, can help health care providers consider nonpharmacologic interventions, Kwoh agreed, such as physical therapy or braces. “It doesn’t have to be drugs. We have limited drugs for OA at the moment. We don’t have a so-called DMARD drug [for OA].”
NSAIDs have side effects, and people are very familiar with the issues of opioids, he said. It’s important, he added, for the health care provider, if referring to a physical therapist, to find the right one. To help those dealing with knee OA, a PT in sports medicine might be a good choice, he said.
Jakiela has no disclosures. Kwoh and White have no relevant disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.