Previous conceptions of the 'best' predictive factors for the radiographic outcome of early rheumatoid arthritis (RA) patients have been challenged by French researchers.
Their prospective study identified a novel set of factors, not including Health Assessment Questionnaire (HAQ) disability, that they claim best predict radiographic outcome after 10 years in patients with early RA.
"Predicting RA outcome is fundamental for optimal clinical management," note Bernard Combe (Lapeyronie Hospital, Montpellier, France) and co-workers in the journal Arthritis Research and Therapy.
"Radiographic damage is frequently used as a major assessment criteria for outcome in RA," the authors say, adding: "Numerous studies have identified possible initial individual factors associated with worse radiographic outcome."
But they note: "There are many discrepancies between the studies and few were conducted prospectively for a long term."
To help overcome these limitations, Combe and team prospectively studied 112 individuals with early RA.
The researchers correlated data on the patients' condition at the start and end of the 10-year follow-up period with radiographic disease progression over that period.
Analysis revealed that joint erosion score taken at the start of the study was the most important predictor for total radiographic Sharp score 10 years later, the researchers report.
Sharp score at 10 years was also significantly and independently predicted by the presence of anti-citrullinated protein antibodies and by erythrocyte sedimentation rate.
Interestingly, a patient's score on the Health Assessment Questionnaire significantly predicted disease activity score and pain at baseline and at 3, 5 and 10 years, but did not, at any point during follow-up, predict total radiographic Sharp score.
Concluding, the investigators point out that the radiographic scores they report after 10 years are lower than those documented in previous reports, and suggest that this "may be due in part to the early start of therapy with disease-modifying anti-rheumatic drugs."
The authors argue that, if this is the case, the expected links between Health Assessment Questionnaire score and Sharp score may appear "much later in the evolution of the disease."