Relationship between biological factors and catastrophizing and clinical outcomes for female patients with knee osteoarthritis

AIM: To investigate the correlations between clinical outcomes and biopsychological variables in female patients with knee osteoarthritis (OA). METHODS: Seventy-seven patients with symptomatic knee OA were enrolled in this study. We investigated the age, body mass index (BMI), pain catastrophizing scale (PCS) and radiographic severity of bilateral knees using a Kellgren-Lawrence (K-L) grading system of the subjects. Subsequently, a multiple linear regression was conducted to determine which variables best correlated with main outcomes of knee OA, which were pain severity, moving capacity by measuring timed-up-and-go test and Japanese Knee Osteoarthritis Measure (JKOM). RESULTS: We found that the significant contributor to pain severity was PCS (β = 0.555) and BMI (β = 0.239), to moving capacity was K-L grade (β = 0.520) and to PCS (β = 0.313), and to a JKOM score was PCS (β = 0.485) and K-L grade (β = 0.421), respectively. CONCLUSION: The results suggest that pain catastrophizing as well as biological factors were associated with clinical outcomes in female patients with knee OA, irrespective of radiographic severity.