Exploring the impact of illness uncertainty on psychosocial and functional outcomes in knee osteoarthritis

Knee osteoarthritis (KOA) is a prevalent chronic condition. While uncertainty is linked to poorer quality of life in chronic conditions, its impact on KOA remains unexplored. This study aims to investigate the relationship between illness uncertainty and key outcomes such as quality of life and multidimensional variables in patients with knee osteoarthritis. Observational cross-sectional study conducted among patients with essential clinical diagnosis of knee osteoarthritis according to the diagnostic criteria established by the American Rheumatism Association, recruited by consecutive sampling. Different psychosocial components linked to chronic pain and physical function variables were assessed. Pearson and Kendall correlation analyses were used to examine the relationship between illness uncertainty and quality of life or multidimensional variables. Linear regression analyses were used to assess potential causal relationships. A total of 79 patients met inclusion criteria. Illness uncertainty showed a negative, low, and significant correlation (r = -0.265; p = .018) with quality of life, whilst correlations between illness uncertainty and kinesiophobia (r = 0.497; p < .001), catastrophizing (r = 0.533; p < .001), central sensitization (r = 0.443; p < .001), and anxiety and depression (r = 0.471; p < .001) showed positive moderate significant correlations. No association with physical function performance was evidenced whatsoever (r = -0.106; p = .355). The five statistically significant variables were retained for a multivariate linear regression model (adjusted-R2 = 0.373), in which central sensitization (p = .038) and kinesiophobia (p = .040) showed statistical significance. This study highlights the importance of assessing and treating illness uncertainty in patients with KOA through interventions based in personalized, biopsychosocial, and multidimensional approaches to improve the psychosocial components associated with knee osteoarthritis.