Foot and Ankle Problems in Patients With Rheumatoid Arthritis in 2019: Still an Important Issue

OBJECTIVE: To study the prevalence of foot pain in patients with rheumatoid arthritis (RA) and whether including a 12‐joint foot count in addition to the 28‐joint count (from the Disease Activity Score 28 [DAS28]) improved detection of foot or ankle pain. In addition, the association between the self‐reported foot and ankle score (SEFAS), patient‐reported function, and disease‐specific factors was studied. METHODS: Physician‐reported data (swollen/tender 12‐joint foot count, DAS28, and medication) and patient‐reported data (foot/ankle pain, physical function, global health, and SEFAS) were assessed during a clinical visit. Data were analyzed with t test, χ(2) tests, and regression analysis. RESULTS: A total of 320 patients with RA were included (mean age 63 years, SD 13 years; 73% women), of whom 69% reported foot or ankle pain. Patients who reported foot or ankle pain had a lower mean age and worse disease activity, general pain, function, and global health (P ≤ 0.016), and fewer were in remission (50% versus 75%; P < 0.001) compared with patients without foot pain. The 12‐joint foot count identified 3.2% and 9.5% additional patients with swollen and tender joints, respectively, compared with the 28‐joint count. The SEFAS was associated with walking problems (β = −2.733; 95% confidence interval [CI] = −3.963 to −1.503) and worse function (β = −3.634; 95% CI = −5.681 to −1.587) but not with joint inflammation severity. CONCLUSION: The prevalence of foot or ankle pain in patients with RA is high. The 12‐joint foot count had minor effects on detecting patients with foot pain. However, the SEFAS contributed additional information on foot problems that was not identified by joint examinations alone.