To identify predictors of long-term pain and disability in knee osteoarthritis.
A longitudinal cohort study of five years.
Primary care providers.
In all, 108 patients (mean age = 63.6 years, standard deviation (SD) = 7.2 years) with knee pain (⩾40 mm on a 100 mm visual analogue scale in the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index pain scale) and radiographic grading (Kellgren-Lawrence: 2-4) of knee osteoarthritis who participated in a randomized controlled trial.
Disease-specific pain and functioning were assessed using the corresponding WOMAC subscales. Generic functioning was assessed by the RAND-36 subscales for function and physical and mental component summary scores. Possible baseline predictors for these outcomes were (1) demographic and disease-related variables and (2) psychological variables of mood (anxiety, depression), pain-related cognitions (pain self-efficacy, pain catastrophizing, kinesiophobia), and positive resource factors (life satisfaction, sense of coherence).
Multivariate linear mixed model analyses revealed that minimal anxiety at baseline predicted significantly better results for pain (WOMAC, 
Anxiety, pain-related cognitions, and psychological resources predict symptoms in knee osteoarthritis in the long term.