Web-­based Study of Risk Factors for Pain Exacerbation in Osteoarthritis

Abstract

Objectives: The pain experienced by osteoarthritis (OA) patients is not constant and patients experience episodes of pain exacerbations. Using an innovative web based case-crossover design, we evaluated whether psychological factors and knee injury/buckling are risk factors for pain exacerbations in knee OA. Methods: In a 3-months internet-based case-crossover study, participants with symptomatic knee OA were followed at 10-day intervals (control periods). Participants were also instructed to log on to the study website if they experienced a knee pain exacerbation (case periods). The relation of psychological factors and knee injury/buckling to the risk of pain exacerbation was examined using conditional logistic regression. Results: Higher negative affect (odds ratio (OR) 6.49; 95% CI 3.45-12.2) and passive coping strategies (OR 1.26; 95% CI 1.05-1.50) were associated with increased risk of pain exacerbations; while higher active coping strategies (OR 0.81; 95% CI 0.66-0.98) had a protective effect. Sustaining a knee injury and buckling increased the risk of a pain exacerbation (OR 10.2; 95% CI 5.4, 19.3 and OR 4.0; 95% CI 2.6, 6.2 respectively). Conclusion: The findings emphasize the need for avoidance of negative affect, passive pain coping strategies and knee injury/buckling and conversely reinforce the benefit of active pain coping strategies in prevention and management of OA pain exacerbations.