Background/Purpose:

Knee osteoarthritis (OA) is a leading cause of disability and no effective disease-modifying treatment currently exists. Identifying factors associated with clinical outcomes may help to better understand the disease and provide insight for new treatment. Previous studies have found that personality, the multifaceted characteristics underlying a personÕs affect, cognition, and behavior, may influence OA impact. The aim of the study was to clarify whether personality dimensions are associated with pain, function, psychosocial health, self-efficacy, and outcome expectations among patients with knee OA.

Methods:

We performed a secondary analysis using baseline data from a randomized controlled comparative effectiveness trial between Tai Chi and physical therapy for knee OA. Patients enrolled were 40 years or older and met American College of Rheumatology criteria for symptomatic knee OA with radiologic evidence. Personality was assessed using the NEO-Five Factor Inventory, a validated measure of five basic personality dimensions: agreeableness, conscientiousness, extraversion, neuroticism, and openness. Outcome measures included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores, patientsÕ global assessment for OA severity, six-minute and twenty-meter walk tests, health-related quality of life, depression, self-efficacy, and outcome expectations for exercise. Pearson correlation analysis was performed to assess the associations between personality dimensions and health outcomes.

Results:

There were 34 participants, 71% female, mean age 60 years, body mass index 33 kg/m², 56% white, and mean duration of knee pain 11 years. Higher conscientiousness was associated with better outcome expectations and physical component of quality of life as well as marginally correlated with better self-efficacy. Both higher openness and extraversion were also associated with higher outcome expectations, and higher openness had significant correlation with better self-efficacy. Higher neuroticism marginally correlated with worse depression. Agreeableness was not significantly associated with any outcome. None of the five personality dimensions were significantly associated with WOMAC pain and function, patientsÕ global assessment, walk test performance, or mental health (Table 1).

Conclusion:

Personality significantly correlated with a variety of health outcomes including outcome expectations, physical component of quality of life, and self-efficacy, but was not associated with the level of pain or function in patients with knee OA. The results further elucidate characteristics of OA patients, and implicate that individualized interventions taking personality into consideration may promote well-being in patients with knee OA. Future longitudinal studies with a larger sample are warranted to further inform clinical practice.