Session Information
Date: Tuesday, November 7, 2017
Title: Osteoarthritis – Clinical Aspects Poster II: Observational and Epidemiological Studies
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: For some individuals with knee osteoarthritis (OA), the failure of conservative management can often lead to knee replacement (KR). Identifying who will progress to KR may allow efficient dedication of resources towards this group with interventions that may delay or prevent the need for surgery. To date, self-reported pain severity and function has not provided sufficient prediction of KR. The speed of a person’s gait is a powerful predictor of significant health events in older adults. Gait speed may encapsulate a range of functional limitations and impairments that could precipitate the need for KR and may therefore be an appropriate measure that predicts the need for KR in patients with knee OA. At the same time, because KRs occur in older individuals, observational studies need to properly account for competing risk of death and study withdrawal to obtain valid estimates of risk of KR. The aim of this study was to investigate the relation of gait speed to incident KR in older individuals with or at risk for knee OA.
Methods: The MOST Study is a NIH-funded cohort of persons with or at risk of knee OA. MOST participants completed baseline, 30-, 60-, and 84-month clinic visits. Gait speed at the baseline clinic visit was calculated from the time taken to complete the 20-meter walk test (meters(m)/second(s)). Date of first KR was confirmed. Participants without a KR were censored at their last attended clinic visit. We examined the relation of gait speed to KR using a Cox proportional hazards model accounting for competing events. Participants without a KR were censored at their 84-month visit, and death and early withdrawals were considered competing events. In separate models, we dichotomized gait speed at values related to functional limitation and community walking speed (1.0 and 1.2 m/s, respectively), and also into tertiles. Analyses were adjusted for age, sex, BMI, clinic site, baseline knee pain severity (visual analog scale 0-100 in the most painful knee) and baseline Kellgren-Lawrence (KL) score (maximum of right and left).
Results: 2774 participants were included: mean±SD age, BMI, and gait speed were 62.3±8.0, 30.6±6.0, and 1.20±0.2, respectively; 60% were female. 47% and 15% of participants walked at 1.0 and 1.2 m/s at baseline, respectively. While lower gait speeds were associated with higher risk of KR in the crude model, once we accounted for the confounding effects of pain severity and the competing risk of death and study withdrawal, lower gait speeds were no longer associated with incident KR (Table). Compared with the highest gait speed tertile, those in the lowest had 1.2 (0.9, 1.6) times the risk of KR.
Conclusion: Gait speed was not a strong predictor of KR once we accounted for the confounding effects of pain and competing risk of death and study withdrawal.
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Hazard Ratio (95% CI) for KR (n=2774) |
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Crude |
Adjusted for age, sex, BMI, clinic site, KL score, and knee pain severity |
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20-m walk <1.0 m/s |
2.1 (1.7, 2.5) |
1.0 (0.8, 1.3) |
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20-m walk <1.2 m/s |
2.2 (1.8, 2.7) |
1.1 (0.8, 1.4) |
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20-m walk (range) Lowest Tertile (0.2-1.13) Middle Tertile (1.14-1.29) Highest Tertile (1.3-1.9) |
3.0 (2.3-3.8) 1.7 (1.3-2.2) 1.0 (ref)
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1.2 (0.9-1.6) 1.2 (0.9-1.5) 1.0 (ref)
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To cite this abstract in AMA style:
Stefanik J, McClelland J, Brown C, LaValley MP, Torner J, Nevitt M, Lewis CE, Neogi T. Relation of Gait Speed to Incident Knee Replacement: The Multicenter Osteoarthritis Study [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/relation-of-gait-speed-to-incident-knee-replacement-the-multicenter-osteoarthritis-study/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/relation-of-gait-speed-to-incident-knee-replacement-the-multicenter-osteoarthritis-study/