P203 Prevalence of lower limb disease activity and walking disability in the first two years of rheumatoid arthritis: results from the Scottish Early Rheumatoid Arthritis inception cohort

Abstract

Abstract Background/Aims Lower limb synovitis and walking disability are reported as common in rheumatoid arthritis (RA), however there is a paucity of contemporary longitudinal studies reporting prevalence rates from disease onset. The aims of this study were to determine i) the prevalence of lower limb synovitis and walking disability from first presentation to 2 years, and ii) the prevalence of active foot/ankle disease amongst participants in Disease Activity Score-28 (DAS28)-remission. Methods The Scottish Early Rheumatoid Arthritis (SERA) study is an inception cohort of newly diagnosed inflammatory arthritis patients attending rheumatology units across Scotland. SERA data included demographics and 6-monthly clinical outcome data. Data from participants diagnosed with RA were included. Synovitis was determined using tender and swollen joint counts recorded at hips, knees, ankles and metatarsophalangeal (MTP) joints 2-5, and dichotomised as present (≥1) or absent (0). Walking disability was measured using the Health Assessment Questionnaire (HAQ) walking subscale (range 0-3) and dichotomised at present (≥1) or absent (0). Prevalence rates are expressed as percentages of participants. Subgroup analysis was performed to estimate the prevalence of foot/ankle joint swelling in participants who were in DAS28-remission (<2.6). Results A total of 932 participants (65.9% female) with a median (interquartile range [IQR]) age 59.5 years (49.5-68.1) were included, dropping to 391 at 2 years. Prevalence rates for lower limb synovitis and walking disability are reported in table 1. At 6 months, 138/816 (28.6%) participants met DAS28-remission criteria, followed by 124/691 (31.9%) at 1 year, 118/522 (39.2%) at 18 months, and 88/391 (39.5%) at 2 years. For those in DAS28-remission the prevalence of foot/ankle joint swelling was 10.3% at 6 months, 13.5% at 1 year, 17.6% at 18 months and 12% at 2 years. Conclusion Prevalence rates for knee, ankle and MTP joint swelling are initially high then stabilise, with largest reductions observed at 6 months. Joint tenderness prevalence rates follow a similar course but are consistently higher than joint swelling. Walking disability affects a significant proportion of patients throughout the first 2 years of RA. Clinically important rates of active foot/ankle disease are present amongst those classed in DAS28-remission. Disclosure N. Kelleher: None. G.J. Hendry: None.