Laboratory and imaging studies used by French rheumatologists to evaluate patients with early arthritis

To conduct a practice survey of laboratory and imaging studies used by French rheumatologists to identify the cause of recent-onset arthritis.

We selected a random sample of 210 rheumatologists, who were asked to recruit all patients with recent-onset arthritis (at least one joint involved, for less than one year) during a 2 week period, and to record laboratory and imaging studies performed. Results were analyzed in the overall group, in diagnostic subgroups, and in clinical presentation subgroups.

The 119 rheumatologists who participated recruited 104 patients. Investigations done in 50% to 75% of patients were blood cell counts; erythrocyte sedimentation rate; serum assays of C-reactive protein, rheumatoid factors, antinuclear antibodies; and hand radiographs. Investigations in 50% to 74% of patients were serum ASAT/ALAT, creatinine, and uric acid; and foot radiographs. Finally, 25% to 49% of patients were tested for proteinuria; antikeratin antibodies; hepatitis B, hepatitis C, and Lyme serologies; creatine phosphokinase; blood iron; HLA-B27; and radiographs of chest and pelvis. No differences were found between investigations in patients with suspected rheumatoid arthritis and/or undifferentiated arthritis and those in other patients. In contrast, suspected diagnoses and presence of extraarticular manifestations classically associated with specific diseases modified the selection of investigations.

Although considerable variability occurred, our study suggests that a limited panel of laboratory and imaging studies is performed in at least 25% of patients with recent-onset arthritis, regardless of clues suggesting a specific diagnosis.