Evaluation of the CASPAR criteria for psoriatic arthritis in the Chinese population.

OBJECTIVE

To evaluate and validate the Classification of Psoriatic Arthritis (CASPAR) criteria for PsA in a Chinese population.

METHODS

Data were collected prospectively from consecutive Han Chinese clinic attendees with PsA and other chronic inflammatory arthritis. Subjects were classified according to Moll and Wright, European Spondyloarthropathy Study Group (ESSG) criteria for PsA, Vasey and Espinoza or CASPAR criteria. Sensitivity and specificity of each set of criteria were compared with the expert clinical diagnosis. Latent class analysis was used to calculate accuracy of criteria and confirm validity.

RESULTS

A total of 108 (53 males and 55 females) subjects with PsA were recruited. Mean (s.d.) age and duration of illness were 48.4 (12.0) and 9.55 (7.66) years, respectively. Data were compared with 195 controls with RA (n = 154) and AS (n = 41). The ESSG criteria have the lowest sensitivity, followed by the Moll and Wright criteria. The sensitivity and specificity for the CASPAR criteria were 98.2 and 99.5%, respectively, which is similar to reported values in European populations. The latent class model agreed closely with the clinical criteria.

CONCLUSIONS

The CASPAR criteria performed well in a Chinese population, which is very different from the populations for which they were developed. The CASPAR criteria have higher sensitivity in classifying PsA.