Kelli D. Allen
Although black adults with knee osteoarthritis demonstrate worse performance-based physical function than white patients, these disparities are diminished when adjusting for socioeconomic and physical health factors, according to findings published in Arthritis Care & Research.
“Physical function is a very important outcome for people with osteoarthritis, since reduced function can lead to disability and interfere with participation in valued life activities,” Kelli D. Allen, PhD, of the Thurston Arthritis Research Center at the University of North Carolina Chapel Hill, told Healio Rheumatology. “Prior studies have found that African Americans with osteoarthritis report worse physical function than Caucasian counterparts.”
“However, self-reported function doesn’t always reflect actual physical function,” she added. “So, an advance of this study was that it looked at racial differences in several tests of physical function that mirror actual daily activities, like standing up from a chair and sitting back down.”
Although black adults with knee OA demonstrate worse physical function than white patients, this is diminished when adjusting for socioeconomic and physical health factors, according to findings.
To analyze differences between black and white patients with OA regarding performance-based physical function, as well as the potential factors that contribute to these disparities, Allen and colleagues conducted a cross-sectional study of participants from the Physical Therapy vs. Internet-Based Exercise Training (PATH-IN) for Patients with Knee Osteoporosis trial. According the researchers, that randomized controlled trial, which recruited 350 participants from the University of North Carolina and surrounding areas, compared physical therapy to an internet-based exercise intervention in patients with knee OA.
All PATH-IN participants performed a series of physical function tests. For the timed-up and go test, patients were timed as they rose from a chair, walked 3 meters, turned around, walked back and sat in the chair again. In the 2-minute step test, participants stood near a wall as they stepped in place, bending their knees to a height at least half the distance between the patella and the iliac crest, as many times as possible in 2 minutes. For the 30-second chair stand test, patients rose from a normal sized chair and sat back down as many times as possible within 30 seconds.
Allen and colleague examined data from 322 PATH-IN participants who identified as either black or white. Of these participants, 22% were black and 72% were women. Covariates included age, sex, BMI, physical activity, pain, physical health, depression, fear of movement, education, employment, financial status and marital status.
According to the researchers, black participants demonstrated a greater unadjusted likelihood of worse physical function compared with whites. This was evident in results from the timed-up and go test (OR = 3.71; 95% CI, 2.16-6.36), the 2-minute step test (OR = 2.37; 95% CI, 1.4-4.03) and the 30-second chair stand test (OR = 2.79; 95% CI, 1.65-4.72). In addition, this likelihood persisted when adjusting for demographic and psychological health covariates, such as age, sex or depression. However, the relationship diminished or was made nonsignificant when adjusted for socioeconomic and physical health.
“These findings highlight the importance of assessing function in clinical settings and providing interventions to patients who have limitations,” Allen said. “Although our study results suggest that African Americans with OA are at greater risk for functional limitations than Caucasians, any patient with OA can suffer from reduced function and the associated negative consequences.”
“Osteoarthritis treatment guidelines indicate that physical activity and weight management are key, first line management strategies, but both are underutilized,” she added. “Increasing referrals to physical activity and weight management programs or resources could help to improve functional outcomes for African Americans and all patients with OA.” – by Jason Laday
Disclosure: The researchers report no relevant financial disclosures.