Table 1.

Papers on the confirmation of the diagnosis of RA

Paper	Design	Study population	Diagnostic test for RA	Reference standard*	Time interval	Sens, % (95% CI)	Spec, % (95% CI)	RoB
Pedersen, 201416	CS	Patients with self-reported RA (n=51)	ACR 1987 criteria Adapted ACR 1987 criteria adding: GS synovitis, US erosions, RF GS synovitis, US erosions, ACPA GS synovitis, erosions on X-ray, ACPA PD synovitis, US erosions, ACPA RAMRIS scale for synovitis (MCP joints 2–5) RAMRIS scale for synovitis (combined wrist and MCP joints 2–5)	Clinical diagnosis according to a rheumatologist	NR	44 (22 to 69) 72 (47 to 90) 72 (47 to 90) 56 (31 to 79) 39 (17 to 64) 69 (39 to 91) 62 (32 to 86)	94 (81 to 99) 91 (77 to 83) 87 (73 to 97) 91 (77 to 98) 100 (90 to 100) 100 (73 to 100) 94 (73 to 100)	L

*A clinical diagnosis according to a rheumatologist was deemed as the appropriate reference standard.

ACPA, anti-citrullinated protein antibody; ACR, American College of Rheumatology; CS, cross-sectional; GS, Grey scale; L, low (green); MCP, metacarpophalangeal; NR, not reported; PD, power doppler; RA, rheumatoid arthritis; RAMRIS, Rheumatoid arthritis MRI scoring system; RF, rheumatoid factor; RoB, risk of bias; sens, sensitivity; spec, specificity; US, ultrasonography.