Identify good response predictors to intra-articular injection (IAI) with triamcinolone hexacetonide (TH).
This study was carried out in rheumatoid arthritis (RA) patients (American College of Rheumatology criteria) submitted to IAI (mono, pauci or polyarticular injection).
A "blinded" observer prospectively evaluated joints at one week (T1), four weeks (T4), twelve weeks (T12) and 24 weeks (T24) after IAI. Outcome measurements included Visual Analogue Scale (0-10 cm) at rest, in movement and for swollen joints. Clinical, demographic and variables related to injection at baseline were analyzed according to IAI response.
We studied 289 patients with RA (635 joints) with a mean age of 48.7 years (±10.68), 48.5% of them Caucasians, VAS for global pain=6.52 (±1.73). Under univariate analysis, the variables relating the best responses following IAI (improvement > 70%) were: "elbow and metacarpophalangeal (MCP) IAI, and functional class II". Under multivariate analysis, "males" and "non-whites" were the predictors with the best response to IAI at T4, while "elbow and MCP IAI", "polyarticular injection", "use of methotrexate" and "higher total dose of TH" obtained the best response at T24.
Several predictors of good response to IAI in patients with RA were identified. The best-response predictors for TH IAI of long term were "apply elbow and MCP IAI" and "apply polyarticular injection".