Identification of Knee Osteoarthritis Phenotypes Based on Reported Pain Over Time and Response to Available Treatments
Overview:
Osteoarthritis (OA) is a painful joint disease with large societal impact and unsatisfactory treatment options. One of the main symptoms of OA is pain, and treatment options focus on pain relief. Current medications and surgical procedures provide pain relief for some patients, but not all. This discrepancy suggests that there are different groups of patients which require different treatment approaches. In this project, we aim to identify knee OA patient groups looking at pain development over time. We will use an advanced statistical method that accounts for patient pain experience over nine years and each patient’s response to currently available treatments in this period. It will allow us to identify patients in need of new treatment options, as well as to optimise the delivery of the current ones.
Aims and Objectives:
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To identify knee OA groups studying patients’ experience of pain over time.
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To investigate the mutual development of knee pain and knee functional limitations over time.
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To identify patient groups that do and do not benefit from the available treatment options.
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To define a set of criteria to help clinicians to identify patients most likely to benefit from the specific treatment.
Key Findings:
We identified four knee osteoarthritis phenotypes described by low-fluctuating, mild-increasing, moderate-treatment-sensitive, and severe-treatment-insensitive pain.
We detected a patient group that benefited from knee replacement. We also found 3% of patients who had severe pain (intensity 60-70 on a scale up to 100) used painkillers, but such painkillers did not show a significant effect in reducing pain over time, and they had the same chance for arthroplasty as the low fluctuating phenotype. Three out of four patients in this phenotype were women.
We found that functional limitations followed identical development to pain, indicating that people experienced these two outcomes very similarly or could not distinguish between them.
The baseline clinical and lifestyle factors were modest in differentiating the phenotypes. We distinguished painful from minimally painful groups but found little to differentiate moderate from severe pain groups. Body mass index showed a consistently positive relationship with severity of phenotypes, indicating metabolic differences.
Outputs:
- Radojčić, MR, Arden, NK, Yang, X, Strauss, VY, Birrell, F, Cooper, C, Kluzek, S and VIDEO trial investigators. Pain trajectory defines knee osteoarthritis subgroups: A prospective observational study. PAIN. (2020). doi: 10.1097/j.pain.0000000000001975
- Radojčić, MR. Osteoarthritis Phenotypes: https://www.youtube.com/watch?v=1hcTvRMCiRs. August 2020.
- Radojčić, MR, Arden, NK and Kluzek, S. Pain trajectory defines knee osteoarthritis subgroups, NDORMS . 13 August 2020.