Fear avoidance and catastrophizing are associated with both knee awareness and quality of life in knee osteoarthritis patients: a secondary report of a cross-sectional study.

BACKGROUND AND PURPOSE: In patients with knee osteoarthritis (OA), psychological factors (anxiety, depression, and pain-related catastrophizing) are associated with more pain and worse physical function. Low knee awareness and high knee-related quality of life (QoL) are key indicators of a well-functioning knee. The objective of our study was to evaluate associations between psychological factors and knee awareness and knee-related QoL in patients with knee OA.

METHODS

In this Norwegian cross-sectional study of 653 patients with knee OA, 4 psychological factors were assessed: anxiety, depression, pain-related catastrophizing, and fear avoidance of physical activity. Associations between these factors and knee awareness and knee-related QoL were examined in unadjusted and adjusted regression models, controlling for age, sex, BMI, pain, and whether patients accepted or declined inclusion in a randomized controlled trial (ClinicalTrials.gov: NCT03771430). Regression coefficients with values below zero indicate negative associations between the independent and dependent factors and values above zero indicate positive associations.

RESULTS

Worse scores on all 4 psychological measures were associated with higher knee awareness and poorer knee-related QoL in unadjusted analyses. Standardized estimates (βs) ranged from -0.38 (95% confidence intervals [CI] -0.45 to -0.31) to -0.16 (CI -0.23 to -0.08). In adjusted analyses, pain catastrophizing (β -0.07, CI -0.14 to -0.01) and fear-avoidance (β -0.11, CI -0.18 to -0.05) remained associated with higher knee awareness, whereas poorer knee-related QoL remained associated with more anxiety (β -0.10, CI -0.16 to -0.03) and depression (β -0.14, CI -0.20 to -0.08), as well as more pain catastrophizing (β -0.19, CI -0.26 to -0.12) and fear-avoidance (β -0.19, CI -0.25 to -0.13).

CONCLUSION

Higher fear avoidance of physical activity and more pain catastrophizing had the strongest associations with higher knee awareness and poorer knee-related QoL.