Patients with hand osteoarthritis (OA) were found to report higher painful joint counts compared with nurse assessments, according to a study published in Rheumatology (Oxford).
A total of 524 participants from an observational study of primary hand OA were included in the analysis. In the cohort, patients with primary hand OA were asked to indicate painful joints on hand diagrams, which included a total of 30 joints. Nurses applied pressure on the lateral joint margin or used passive joint movement to assess joints for tenderness upon palpation.
Pain was assessed using a visual analog scale and the Australian/Canadian hand OA index subscale pain. Associations between pain measures and joint activity and joint-level associations with synovitis/bone marrow lesions were evaluated.
Approximately 97% of patients reported ≥1 painful joint and trained nurses reported ≥1 tender joint in 81.3% of patients. The painful joint count was higher in self- vs assessor reports of tender joints (median, 8 vs 3, respectively). There was low agreement between patients and nurses on overall scores. The percentage of absolute agreement on the joint level was 61% to 89%.
Weak correlations were observed between self-reported joint count and other pain measures (visual analog scale: r=0.37; Australian/Canadian OA Hand Index pain subscale: r=0.37) and between assessor-reported joint count and pain measures (r=0.38 and r=0.37, respectively).
Study limitations include its observational nature and the use of self-reported pain measures.
“Our results suggest that these two joint counts cannot be used interchangeably.
This does likely not imply that either joint count is more truthful than the other, but rather that pain and tenderness are separate aspects of pain, and in this sense are both of interest,” noted the study authors.
Kroon FPB, Damman W, van der Plas JL, et al. Self-reported painful joint count and assessor-reported tender joint count as instruments to assess pain in hand osteoarthritis [published online September 19, 2019]. Rheumatology (Oxford). doi:10.1093/rheumatology/kez395