Background Although pain in rheumatoid arthritis (RA) is frequently thought to be inflammatory in nature, some studies reported clinically significant pain despite relatively low rheumatoid arthritis (RA) disease activity. Less than 50% of patients are satisfied by the management of pain.

Objectives to report a recent multidimensional evaluation of pain in a large RA population.

Methods Patients with RA were enrolled in 7 French Rheumatology Centers during a visit or a hospitalization in a transversal observational study. Socio-demographic data, previous and prescribed medications, disease duration, immunologic status, DAS28 score were assessed. Patients completed the multidimensional pain questionnaire from french health autority, the health assessment questionnaire (HAQ), the Beck depression scale and the anxiety scale STAI. Joint damage was evaluated by a simple erosion narrowing score.

Results Of the 299 screened patients, 295 were included with a mean age of 58.4±11.7 years, 80.3% of female, a mean disease duration of 13.2±9.6 years, positivity of rheumatoid factors in 76.4%, anti-citrullin antibodies in 74% of cases. Concerning medications, 42.7% were treated by corticoids (mean dose=6.4 mg/d), 66% by analgesic drugs (64.1% with acetaminophen, 45.6% weak opioids, 7.1% strong opioids) and 24.4% with NSAIDs. The RA treatments were DMARDs in 69.1% and biotherapies in 82.7% of cases. The mean DAS-28 score was 3.1±1.3 with 38.7% of patients in remission and 15.4% in low disease activity. The verbal scale for satisfaction about pain management showed that a third of patients was very satisfied, the half satisfied, 16% weakly or not satisfied. The mean pain visual analogic scale (VAS) for the last 8 days was 33.6 mm ±26.5/100. 39% of patients had a pain VAS >40 mm/100. The Beck scale showed a moderate to severe depression in 34,3% of patients. Anxiety was present in 57.5%. The impacts of pain on daily behaviors were more important on work. The pain VAS for the 8 days was correlated with the score of depression et with the DAS-28 score (p<0.0001). The population with a pain VAS >40 mm had a significant more important Beck score, anxiety score, HAQ, DAS-28 score and had more impacts of pain on daily behaviors There was no association between pain and structural damage and disease duration. There was no difference between the populations with VAS>40 or <40 mm in terms of IL-6, IL-17 and IL-33 serum levels. The multidimensional evaluation of pain wasn't different between treatement groups (DMARDs, biotherapies) and between the different biotherapies. Multivariate analysis with principal component analysis found statistically significant associations between pain VAS and depression score, impacts of pain on daily behaviors and between pain VAS and DAS-28.

Conclusions Almost 40% of patients had moderate to severe pain in a population of severe RA followed in hospital centers and treated with biotherapies in more than 80% of cases. Therefore, pain is still a major outcome to consider in RA. But, the proportion of patients with moderate to severe pain is less important than that one published by Taylor et al. Pain is associated with the DAS-28 score, but also with the depression score.

References

1. Taylor P et al. J Int Med Res 2010; 38: 1213–24.

References

Disclosure of Interest None declared