Background Rheumatoid arthritis (RA) is a chronic inflammatory condition associated with well-recognised inflammatory joint features, which are amenable to ultrasound (US) examination. The implementation of US scoring systems in addition to clinical examination could help standardise the way RA is monitored; however, due to variation in local availability of US and sonographer expertise, different scoring systems have been used in clinical practice (1). Despite significant research progress in supporting the role of US in RA, there is no consensus as to which scoring system is most useful.
Objectives To assess whether simplified US protocols for hand examination correlate significantly with a 22 hand joint US score in patients with established rheumatoid arthritis, and correlate the US examination with the disease activity score (DAS-28 score).
Methods This is a cross-sectional study of 224 RA patients stratified based on their DAS-28 scores and assessed using eight preselected US examination protocols including 22, 18, 16, 14, 10, 8 and two different combinations of 4 joints, respectively. Student T, Mann-Whitney U and Kuskal-Wallis tests were employed for analysis of clinical, laboratory and US parameters in the RA patient groups (P<0.05 was considered significant). Spearman's coefficients were used to correlate permutations of pairs of US scores, and US and DAS-28 scores.
Results We found a significant difference between different US hand scores and their ability to detect the presence of active and chronic inflammation in RA patients. The DAS-28 scores correlated very well (R=0.89–1, P<0.05) with the total Power Doppler (PD) scores generated by all US protocols irrespective of patients' disease activity. Simplified US scores missed information on presence of erosions (P<0.05), but were equivalent to the extensive 22 joint score in appreciating the amount of chronic and active inflammation compared to the extensive 22 joint score (P=0.15, P=0.11, respectively).
Conclusions This study showed that preselected simplified US scores could be used in clinical practice to appreciate reliably the disease activity in patients with established RA; however they are less reliable in appreciating the disease burden when compared with an extended protocol for US examination of 22 hand joints. All the simplified US scores correlated very well with DAS-28 scores.
Mandl, P., et al., A systematic literature review analysis of ultrasound joint count and scoring systems to assess synovitis in rheumatoid arthritis according to the OMERACT filter. J Rheumatol, 2011. 38(9): p. 2055–62.
Acknowledgements S. Hussain and P. Sivakumaran contributed equally to the study.
Disclosure of Interest None declared