Background/Purpose:

Patients with moderate disease are an important, and often poorly studied, patient subgroup. The extent to which traditional DMARD therapies adequately control the disease is an important research question. Radiographic damage is a crucial indicator of the success or failure of treatment to adequately control the disease.

Methods:

The Early Rheumatoid Arthritis Study (ERAS) is an inception cohort that recruited 1,465 recent onset, DMARD naïve, RA patients from 9 hospitals in England between 1986 and 1998, with follow up for up to 25 years. Data collected included demographics, disease activity (DAS), functional disability (HAQ) and radiographs of hands and feet (Larsen). A total of 1,409 (96%) patients had at least one DAS score over the first 5 years of follow-up. Patients mean DAS score over the first 5 years was calculated, and patients were split into three categories based on this score. Patients with a mean score of <3.2 were recorded as mild (n=427), 3.2-5.1 as moderate (n=678) and >5.2 as severe (n=304), in accordance with the EULAR definitions. A mixed effects negative binomial regression was conducted to analyse the rate of Larsen progression over the first 5 years of disease. Follow-up year, age at onset, sex, treatment at 5 years, baseline HAQ and baseline HB were controlled for in the model.

Results:

Patients in the severe group were older, more likely to be female, Rheumatoid Factor positive, higher baseline HAQ, lower baseline HB and shorter mean follow-up. Patients in the moderate group had the highest mean time from symptom onset to first secondary care visit. Patients in the mild and moderate groups were more likely to be on mono-therapy DMARD and steroids, while those patients in the severe group were more likely to be on DMARD step up or add-on treatment. Larsen significantly increased over the first 5 years of disease (P<0.001). Those patients in the moderate group had a significantly higher progression of Larsen over the 5 years compared to those patients in the mild group (P<0.001). There was no significant difference in 5 year Larsen progression between the moderate and severe groups.

Conclusion:

Patients with moderate disease had similar radiographic progression to severe disease, whilst controlling for treatment. Similarly, patients with moderate disease had significantly higher Larsen progression compared to those with mild disease.  Results highlight that targeting this group and aiming for remission, or at least better disease control, is as important as for those with high disease.