Abstract
BACKGROUND: The objective of the study was to determine whether psychological and social factors predict the course of limitations in activities in elderly patients with osteoarthritis of the hip or knee, in addition to established somatic and cognitive risk factors. METHODS: A longitudinal cohort study with a follow-up period of three years was conducted. Patients (N = 237) with hip or knee osteoarthritis were recruited from rehabilitation centers and hospitals. Body functions, comorbidity, cognitive functioning, limitations in activities and psychological and social factors (mental health, vitality, pain coping and perceived social support) were assessed. Statistical analyses included univariate and multivariate regression analyses. Psychological and social factors were added to a previously developed model with body functions, comorbidity and cognitive functioning. RESULTS: In knee OA, low vitality has a negative impact on the course of self-reported and performance-based limitations in activities, after controlling for somatic and cognitive factors. In hip OA, psychological and social factors had no additional contribution to the model. CONCLUSION: Low vitality predicts deterioration of limitations in activities in elderly patients with osteoarthritis of the knee, in addition to established somatic and cognitive risk factors. However, the contribution of vitality is relatively small. Results of this study are relevant for the group of patients with knee or hip OA, attending hospitals and rehabilitation centers.