|The following article is part of conference coverage from the European League Against Rheumatism (EULAR) Congress 2018 in Amsterdam, The Netherlands. Rheumatology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts in rheumatology. Check back for the latest news from EULAR 2018.|
In individuals with radiographic knee osteoarthritis (OA), greater structural disease activity and decreased physical performance were associated with a higher risk for depressive symptoms, according to data presented at the European League Against Rheumatism (EULAR) Congress held in Amsterdam, June 13 to 16, 2018.1
To determine which components of OA disease activity are associated with onset of depression, researchers recruited participants from the Osteoarthritis Initiative who had radiographic disease (Kellgren-Lawrence [K-L] grade 2, 3, or 4), who had complete baseline covariate data, and who were below the screening threshold for probable depression (Center for Epidemiological Studies Depression [CES-D] Scale ≤16).
Researchers assessed OA disease severity with 3 OA disease severity predictors, including structural severity, physical performance, and pain at baseline and at 3 annual follow-up visits, using minimum joint space width, 20-meter gait speed, and pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively.
OA disease severity predictors were evaluated as a moving average at each time point, and were then categorized in quintiles. Joint space width and gait speed categories were inverted so that increasing quintiles corresponded with greater disease severity.
Depression onset was assessed at 4 annual follow-up visits using the CES-D. Potential confounders included time-invariant measures including demographics, lifestyle factors, socioeconomic status, Charlson comorbidity index, K-L grade, and WOMAC functional disability and joint stiffness. Additional confounders included time-varying measures such as CES-D score, body mass index, analgesic use, and knee injuries. The association between each time-varying disease severity predictor and depression onset was modeled with marginal structural models that accounted for time-dependent confounding and selective attrition.
The researchers found that in 2 of the 3 OA disease severity predictors, structural severity and physical performance, depressive symptom onset was associated with increased severity of the predictor.2 The odds ratios comparing highest to lowest severity quintiles in order of increasing magnitude were 1.80 for gait speed (95% CI, 1.00-3.24), 2.10 for joint space width (95% CI, 1.17-3.75), and 2.21 for pain (95% CI, 1.14-4.30).1
“Given the results of our study, we believe that to effectively treat individuals with radiographic knee OA and comorbid depressive disorder, it is necessary to use a combined treatment strategy of 2 interventions delivered in parallel to simultaneously target each condition,” said Alan M. Rathbun, PhD, MPH, research associate in the departments of epidemiology and medicine at the University of Maryland School of Medicine, and special fellow at the Geriatric Research Education and Clinical Center in the VA Maryland Health Care System.2
This study was supported by the Rheumatology Research Foundation’s Scientist Development Award.
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- Rathbun AM, Evans Z, Shardell M, et al. Association between disease severity and onset of depression in knee osteoarthritis. Presented at: European League Against Rheumatism (EULAR) Congress 2018; June 13-16, 2018; Amsterdam, The Netherlands. Abstract OP0003.
- Onset of depressive symptoms significantly associated with disease severity in patients with knee osteoarthritis [press release]. Amsterdam, The Netherlands: Annual European Congress of Rheumatology (EULAR) 2018. Published June 14, 2018. Accessed June 14, 2018.