Background The prognosis for patients with inflammatory polyarthritis (IP) varies and it is difficult to identify at onset which patients will ever achieve remission.
Objectives To examine the disease characteristics at i) baseline and ii) five years of patients who persistently, intermittently, or never achieve remission within the Norfolk Arthritis Register (NOAR) over five years.
Methods NOAR is a primary-care-based cohort of adults with recent onset IP (≥2 swollen joints lasting for >4 weeks). Disease related information collected over 5 years includes 51- swollen and tender joint counts, HAQ, and DAS28. This study included patients recruited between 2000 to 2004 with a symptom duration of <2 years at baseline. Patients in ‘natural remission’ (absence of joint swelling and tenderness from 1st to 5th year in absence of DMARD treatment) or with missing 51- joint count data at any year were excluded. Remission criteria (no tender or swollen joints on examination) were applied at the 1st, 2nd, 3rd and 5th year assessments. 436 patients were grouped according to whether they met the remission criteria persistently at every assessment (PR: N=17), intermittently (IR: N=169), or never (NR: N=254). Baseline differences were analysed using ANOVA for normally distributed continuous variables, Kruskal-Wallis for non-normally distributed variables, and Chi-Square for categorical variables. Ordinal regression was used to examine the relationship between baseline HAQ and DAS28 scores and remission group. Linear or median regression was used to examine the effect of remission group on 5th year HAQ and DAS28 scores. All regression analyses estimates were adjusted for age and gender.
Results Group NR had the highest disease severity at baseline (Table). Group PR were significantly more likely to be on DMARDs at baseline, but the duration on DMARDs at baseline did not differ significantly between groups. Patients with higher HAQ scores (adjß=0.44, 95% CI 0.07, 0.80) or DAS28 scores (adjß=0.47, 95% CI 0.26, 0.68) at baseline, were more likely to be in the IR or NR group. There was a significant effect of remission group on 5th year HAQ scores (p<0.001). Group NR had significantly higher 5th year HAQ scores than Group IR (adjß=0.87, 95% CI 0.69, 1.06) or Group PR (adjß=1.09, 95% CI 0.65, 1.53). There was also a significant effect of remission group on 5th year DAS28 scores (p<0.001). Group NR had significantly higher 5th year DAS28 scores than Group IR (adjß=1.18, 95% CI 0.94, 1.42) andGroup PR (adjß=1.65, 95% CI 1.10, 2.21).
Conclusions A small proportion of patients achieved persistent remission, and patients in this group were more likely to have had DMARD treatment at baseline.
Acknowledgements Funded by Arthritis UK and GlaxoSmithKline.
Disclosure of Interest None Declared