Erratum

In the article ‘Disease-modifying anti-rheumatic drugs for refractory severe knee synovitis in patients with peripheral spondyloarthritis: efficacy and predictors of response’ by GT Sakellariou, FE Sayegh, AD Anastasilakis, I Bisbinas, GA Kapetanos (Scand J Rheumatol 2013;42:369–72), the authors report three errors in Table 1.

Table 1. Demographic and clinical characteristics of the studied patients.

	All patients	Knee synovitis responders	Knee synovitis non-responders	Knee synovitis responders vs. non-responders,
Parameter	(n = 45)	(n = 14)	(n = 31)	p-value
Age at disease onset (years)	33.2 ± 1.7	29.2 ± 1.8	35.0 ± 2.3	0.054
Time interval between disease onset  and DMARD initiation (years)	4.6 ± 0.7	5.8 ± 1.7	4.1 ± 0.6	0.376
Male gender	33 (73.3)	10 (71.4)	23 (74.2)	0.846
Disease subtype				0.011
AS	5 (11.1)		5 (16.1)
PsA	22 (48.9)	4 (28.6)	18 (58.1)
unSpA	18 (40.0)	10 (71.4)	8 (25.8)
Psoriasis ever	22 (48.9)	4 (28.6)	18 (58.1)	0.067
HLA-B27*				0.023
Positive	9 (47.4)	2 (20.0)	7 (77.8)
Negative	10 (52.6)	8 (80.0)	2 (22.2)
Pattern of arthritis at DMARD therapy  onset				0.577
Monoarthritis	14 (31.1)	4 (28.6)	10 (32.3)
Oligoarthritis	29 (64.5)	10 (71.4)	19 (61.3)
Polyarthritis	2 (4.4)		2 (6.4)
Pattern of DMARD therapy				0.681
Monotherapy	37 (82.2)	12 (85.7)	25 (80.6)
Combination	8 (17.8)	2 (14.3)	6 (19.4)

DMARD, Disease-modifying anti-rheumatic drug; AS, ankylosing spondylitis; PsA, psoriatic arthritis; unSpA, undifferentiated spondyloarthritis. *Included only the patients with known HLA-B27 status (n = 19). Values given as mean ± standard error of the mean (SEM) or n (%).

The fourth line of the second column should be blank

The fifth line of the second column should read 4 (28.6)

The sixth line of the second column should read 10 (71.4) The correct table is printed below. We apologize for this error.