To evaluate the ability of baseline hand radiographs to predict the diagnosis 2 years later in a cohort of patients with early arthritis.
A total of 258 patients with arthritis onset within the previous year were evaluated. At baseline, all patients underwent a standardized evaluation including laboratory tests and radiographs. Hand radiographs were read by a blinded observer who used a standardized procedure for detecting features of crystal deposition diseases and rheumatoid arthritis (RA). After 30 +/- 11.3 months, the final diagnosis was established by a panel of rheumatologists. All radiographs were evaluated.
Significant associations were found between radiographic features and a clinical diagnosis of RA, calcium pyrophosphate dihydrate (CPPD) arthritis, and hydroxyapatite arthritis. No radiographic abnormalities suggesting psoriatic arthritis or gout were seen. The sensitivities of hand radiographs for diagnosing CPPD or hydroxyapatite arthritis ranged from 80% to 100%. Baseline hand radiographs suggested the final diagnosis in 31/258 patients, including 21 (22.5%) of the 93 patients with RA, 10 of the 11 (91%) patients with CPPD or hydroxyapatite deposition disease, and none of the patients with other disorders. Sensitivity was 29%, specificity 86.5%, positive predictive value 61%, and negative predictive value 63%.
In our cohort of patients with recent arthritis, the overall performance of hand radiographs in predicting a diagnosis 2 years later was modest. However, they had an excellent diagnostic value for calcium deposition diseases.