Background/Purpose:

Analyses of large clinical datasets from early arthritis cohorts permit the development of algorithms that may be used for outcome prediction in individual patients. The value added by routine use of musculoskeletal ultrasound (MSUS) in an early arthritis setting, as a component of such predictive algorithms, remains to be determined.

Methods:

A retrospective analysis of a large, true-to-life, observational inception cohort of early arthritis patients in Newcastle, UK, which included patients with inflammatory arthralgia but no clinically swollen joints, was undertaken. All patients underwent a pragmatic, 10 minute MSUS assessment protocol during their first visit. Logistic regression was used to develop two “risk metrics” that predicted the development of a persistent inflammatory arthritis (PIA), their derivation differing only according to whether or not MSUS parameters were allowed to be incorporated into the final prediction model.

Results:

379 included patients were assigned definitive outcome diagnoses after ≥12 months follow-up (median 28 months), of whom 162 (42%) developed a persistent inflammatory arthritis. A simple risk metric, derived purely from 12 readily obtainable baseline clinical and serological parameters, had an excellent discriminatory utility with respect to an outome of PIA (area under ROC curve 0.91; 95% CI 0.88-0.94). A similar metric, derived from the same 12 parameters in addition to 5 MSUS parameters, had an almost identical, and not significantly superior, discriminatory utility (area under ROC curve 0.91; 95% CI 0.89-0.94)

Conclusion:

MSUS use as a routine component of assessment in an early arthritis clinic does not add substantial discriminatory value to a risk metric for predicting PIA. More work is needed to refine a precise role of this imaging modality as a diagnostic tool in this clinical setting.