Background: Anxiety and depression are more common among patients with rheumatic diseases and can influence treatment options and outcome. However insight in factors associated with anxiety and depression in patients with Spondyloarthritis (SpA) is scarce.

Objectives: To identify factors associated with self-reported anxiety and depression in a well-defined population based cohort of patients with SpA.

Methods: In 2009, 3711 adult SpA patients from the SpaScania cohort were identified and involved in a questionnaire survey including patient reported outcome measures (PROMs) to assess quality of life, physical and mental functioning. To assess depression and anxiety the Hospital Anxiety and Depression Scale (HADS-A and HADS-D) was used. Each subscale ranges from 0-21; best to worst. HAD scores of ≥ 8 indicate probable cases of anxiety or depression.Differences in HADS subscale scores among the SpA subgroups were tested by using one-way ANOVA (p<.05). Associations between PROMs and the HADS subscales, were studied with linear regression analysis including each independent variable separately (adjusted for age, gender and disease duration) and presented as β-estimates (95%CI).

Results: In total 2851 patients (76%) responded to the study invitation, 684 (18%) declined participation and 2167 (58%) returned the questionnaire. Mean age 55.4 (SD 13.9) years, mean disease duration 14.4 (12.1) years and 52% female. SpA subgroups were: Ankylosing spondylitis 501 (23%), Psoriatic arthritis 1171 (54%), and undifferentiated SpA 495 (23%).Mean HADS-A was 5.9 (4.3) and mean HADS-D 4.4 (3.6) respectively for the whole SpA group. In total 683 (32%) cases were classified as probable anxiety cases and 305 (14%) as probable depression cases. No differences in HADS were found among the different SpA subgroups for anxiety or depression (p>0.6).Higher scoring on HADS-A and HADS-D was associated with (table): lower education, lower physical activity (HADS-D only), chronic pain problems, more fatigue, lower general health, lower HRQoL (EQ-5D), lower level of functioning (BASFI), higher disease activity (BASDAI), lower self-efficacy (ASES).

Conclusions: Patients with SpA do report problems with anxiety and/or depression and associations appear highly multifactorial with a profile of impaired health in general. Screening patients with SpA for anxiety and depression in the clinic is important but using a simple proxy is discouraged. Instead HADS or other comprehensive instruments to assess anxiety or depression should be considered.