Objective: To investigate the predictive ability of core outcomes applied in RA trials, including ultrasound (US) Doppler (USD) measurements differentiating patients who remain on anti-TNF-α therapy following 1 year.
Methods: Patients with RA in anti-TNF-α therapy were followed 1 year after therapy initiation. All patients had wrist involvement. At baseline, 2 weeks, 26 weeks and 1 year a USD examination, clinical examination including tender and swollen joint count, visual analogue scale (VAS) global and HAQ, biochemical measures and 28-joint DAS (DAS28) were collected for all patients. The amount of USD signal in the synovium was quantified by measuring the percentage of colour pixels-the colour fraction (CF). Predictive validity for patients who remain on anti-TNF-α therapy after 1 year was assessed for both USD measurements and other disease measures. Baseline values of disease measures of patients who remained on treatment after 1 year was compared with those who stopped therapy.
Results: The study cohort consisted of 109 patients. In this study, the baseline CF was the only measure predicting which patients would stay on the initial anti-TNF-α therapy for 1 year, evaluated using the square-root of CF (P = 0.024). The other disease markers could not significantly differentiate between the two groups of patients, with P-values of 0.86 and 0.98 for tender and swollen joint count, respectively, 0.86 for CRP, 0.24 for VAS, 0.10 for HAQ and 0.38 for DAS28.
Conclusion: There is now evidence to support that baseline USD, in contrast to clinical measures, can predict which patients will remain on anti-TNF-α 1 year after initiating therapy.