Reproducibility of the scleroderma pattern assessed by wide-field capillaroscopy in subjects suffering from Raynaud's phenomenon

Abstract

Objectives: The aim of this work was to study inter- and intra-observer agreement for the diagnosis of scleroderma pattern by wide-field capillaroscopy.

Methods: Images were taken from 50 patients known to have SSc and 50 controls consulting for RP who did not have SSc. These images were rated simultaneously by 11 experienced vascular medicine physicians as scleroderma pattern or not. Two weeks later, 7 of the 11 observers again rated the same images.

Results: Inter-observer agreement was almost perfect between the 11 observers (κ 0.86 ± 0.01), and the proportion of concordant observations was 79% (70-87). When each observer was compared with the reference, agreement was also almost perfect: κ coefficient 0.92 ± 0.03 and proportion of concordant observations 79% (70-87). Intra-observer agreement was also almost perfect: median κ coefficient 0.94 (0.78-0.96) and median proportion of concordant observations 97% (89-98).

Conclusion: Excellent inter- and intra-observer agreement was obtained in experienced vascular physicians for the diagnosis of capillaroscopic landscape by wide-field nailfold capillary microscopy.

Keywords: Raynaud’s phenomenon; nailfold capillaroscopy; reproducibility; systemic sclerosis.