The Course of Comorbid Anxiety Symptoms in Patients Presenting to General Practice with Symptomatic Osteoarthritis: A Latent Class Growth Analysis

Background: Concurrent elevated anxiety symptoms are common in people with symptomatic OA and contribute to levels of disability. Yet it is unclear how often anxiety symptoms present at the time of seeking formal healthcare for OA represent persistent states of anxiety and what factors are associated with different anxiety symptom trajectories. An understanding of the natural course of anxiety symptoms in patients with OA is required to inform clinicians, allocate healthcare resources and improve patients’ awareness.Methods: Participants were older adults consulting general practice with symptomatic OA. Self-completion questionnaires, containing measures of anxiety and depressive symptoms, age, gender, pain status, coping and social status were mailed within 1 week of the consultation and at 3, 6, 12 months. A person-centred approach applying Latent Class Growth Analysis (LCGA) was used to identify clusters of anxiety symptoms, which were ascertained with cut-off score ≥ 8 on the Hospital Anxiety and Depression Scale anxiety subscale. Associations between baseline characteristics and cluster membership were examined using multinomial logistic regression (entry probability p < 0.10).Results: A 4-cluster LCGA anxiety model was supported in 293 participants with complete anxiety data. Clusters were: no anxiety (41.3%), persistent (29.7%), unstable (19.1%) and progressive (9.9%) anxiety. Catastrophizing, coping by increased behavioural activities, pain extent and interference with work, occupational class and perceived lack of instrumental support were differently associated with four anxiety clusters (Table). Age, gender, other coping strategies and factors related to social interactions showed no significant effects on anxiety trajectories.Conclusions: Sixty percent of patients with OA have reported nonnormal anxiety levels over 12 months. In addition, an estimated 60% of patients with symptomatic OA presenting to general practice with concurrent anxiety symptoms will experience persistent anxiety for at least 12 months. Odds ratios suggest that coping by catastrophizing (Adj. OR ¼ 4.25, 95% CI 0.24-0.83) and pain extent (Adj. OR ¼ 1.09, 95% CI 1.04-1.15) are most prominent factors associated with the persistent anxiety trajectoryDisclosure statement: All authors have declared no conflicts of interes