Symptoms of psychological distress, including anxiety and depressive symptoms, and illness perceptions are important in determining outcome in patients with rheumatic disease. We aimed to compare psychological distress in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and to test whether the association between psychological variables and health-related quality of life (HRQOL) was similar in the 2 forms of arthritis.
In 83 PsA patients and 199 RA patients, we used the Patient Health Questionnaire 9 (PHQ-9), the Symptom Checklist-90-Revised, and the Brief Illness Perception Questionnaire to assess psychological variables and the World Health Organization Quality of Life Instrument, Short Form to assess HRQOL. We used hierarchical regression analysis to determine the associations between psychological variables and HRQOL after adjusting for demographic variables and disease parameters.
The prevalence of moderate to severe levels of depressive symptoms (PHQ-9 score ≥10) was 21.7% in PsA patients, 25.1% in RA patients, and 36.7% in those PsA patients with polyarthritis. After adjustment for severity of disease and pain, anxiety (β = -0.28) and concern about bodily symptoms attributed to the illness (β = -0.33) were independent correlates of physical HRQOL in PsA. In RA, depressive symptoms (β = -0.29) and concern about the consequences of the arthritis (β = -0.27) were independent correlates of physical HRQOL.
These findings suggest strongly that psychological factors are important correlates of HRQOL in PsA as well as in RA. Attention to patients' anxiety and their concern about numerous bodily symptoms attributed to the illness may enable rheumatologists to identify and manage treatable aspects of HRQOL in PsA.