Background/Purpose: Mortality is increased in rheumatoid arthritis (RA) in comparison with the general population.  The majority of studies have used the 1987 ACR criteria to define RA when investigating mortality.  The aims of this study were (i) to examine whether, in a cohort of patients with early inflammatory polyarthritis (IP), the 2010 ACR/EULAR classification criteria for RA identify those with decreased survival; and if this is the case (ii) to identify which components of these criteria are the strongest predictors of mortality.

Methods: Consecutive adults with ≥2 swollen joints for ≥4 weeks were recruited to the Norfolk Arthritis Register (NOAR) between 1990 and 2009.  Patients included in this analysis had symptom duration ≤2 years and had not received any disease modifying therapy at initial assessment.  Data on the components of the 2010 criteria, along with demographic details, were obtained at baseline visit through a nurse-administered questionnaire and joint examination.   Patients also completed the health assessment questionnaire (HAQ).  Bloods samples were taken for C-reactive protein (CRP), rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) estimation.  All patients registered with NOAR are flagged with the UK Office for National Statistics (ONS) who provide mortality data.  Survival analyses were performed using Cox proportional hazards models univariately, then adjusting for age and sex.  A multivariate model was then developed including all components of the 2010 criteria as well as baseline smoking status, age and gender.

Results: 1671 patients had complete data for analysis, with 20488 person-years follow up. 1092 (65%) patients were female and there were 471 (28%) deaths reported by the ONS by 31^st December 2011.  905 (54%) patients fulfilled the 2010 criteria at baseline, and these patients had a significantly increased risk of death compared to those patients in NOAR who did not fulfil the 2010 criteria, both univariately and in the age and sex adjusted model, hazard ratio(HR) 1.39 (95% CI  1.15-1.68).  Results of the Cox regression models for the different parameters are shown in the table.  High titre antibody positivity (more than three times the upper limit of normal) was the strongest predictor of mortality in the multivariate model adjusted for all components of the 2010 criteria, age, sex, and smoking status (HR 1.64 (95% CI 1.34 – 2.01)).

Table 1.  Predictors of mortality in the 2010 ACR/EULAR classification criteria for RA

		Univariate		Age & sex adjusted		Multivariate
	n(%)	HR	95% CI	HR	95% CI	HR	95% CI
Satisfy 2010 criteria:     No Yes	766(46) 905(54)	ref 1.56	– 1.29 – 1.88	ref 1.39	– 1.15 – 1.68	– –	– –
Joint score 0 Joint score 1 Joint score 2 Joint score 3 Joint score 5	173(10) 77(5) 372(22) 357(21) 692(41)	ref 1.09 1.15 1.62 1.60	– 0.63 – 1.91 0.77 – 1.74 1.09 – 2.40 1.11 – 2.32	ref 1.31 1.19 1.33 1.42	– 0.75 – 2.31 0.79 – 1.79 0.90 – 1.98 0.98 – 2.06	ref 1.55 1.29 1.36 1.40	– 0.88 – 2.75 0.85 – 1.95 0.92 – 2.03 0.96 – 2.04
RF/ACPA negative RF/ACPA low positive RF/ACPA high positive	1086(65) 171(10) 414(25)	ref 1.02 1.84	– 0.72 – 1.45 1.51 – 2.23	ref 0.93 1.75	– 0.66 – 1.33 1.44 – 2.13	ref 0.90 1.6	– 0.64 – 1.28 1.31 – 1.97
Normal CRP Abnormal CRP	743(45) 928(56)	ref 2.04	– 1.68 – 2.46	ref 1.39	– 1.15 – 1.69	ref 1.25	– 1.02 – 1.52
Disease duration:   6 weeks  ≥6 weeks	88 (5) 1583(95)	ref 0.86	– 0.60 – 1.25	ref 0.88	– 0.61 – 1.28	ref 0.84	– 0.58 – 1.22

Conclusion: In patients presenting with early inflammatory polyarthritis, those who fulfil the 2010 criteria have significantly increased mortality compared to those who did not.  The components of the 2010 criteria which appear to be important predictors of mortality are high titre RF or ACPA positivity, and abnormal CRP at baseline.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/patients-with-early-inflammatory-arthritis-who-fulfil-the-2010-american-college-rheumatologyeuropean-league-against-rheumatism-classification-criteria-for-rheumatoid-arthritis-have-increased-mortalit/