The association of disease activity with depression and sleep quality in patients with rheumatoid arthritis in Hong Kong.

Patients with rheumatoid arthritis (RA) often experience depression and poor sleep. Depression and poor sleep may, in turn, worsen RA disease activity. This cross-sectional study aimed to investigate the relationship between RA disease activity as measured using the Disease Activity Score-28 (DAS28-ESR), depression measured using the Beck's Depression Inventory-II (BDI-II), and sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI).