Table 1.

Characteristics of studies included in the systematic review.

References	PsV/PsA	Country	No. of subjects	Study design
Chicharro et al.19	PsV	Spain	33	Prospective, single centre
De Keyser et al.11	PsV	Belgium, the Netherlands	137	Prospective, multicentre
Dand et al.8	PsV	UK	1326	Retrospective, multicentre
Ovejero-Benito et al.15	PsV	Spain	95	Prospective, single centre
Prieto-Pérez et al.10	PsV	Spain	144	Prospective, single centre
Ovejero-Benito et al.16	PsV	Spain	78	Prospective, single centre
Lu et al.26	PsV	China	43	Prospective, single centre
Masouri et al.9	PsV	Greece	N/A	Retrospective, single centre
Nishikawa et al.17	PsV	Japan	65	Prospective, multicentre
Tan et al.22	PsV	US	N/A	Prospective, multicentre
Lima et al.27	PsV	Brazil	38	Prospective, single centre
Hoffman et al.29	PsV	Germany	146	Retrospective, single centre
Kivelevitch et al.18	PsV	US	35	Prospective, single centre
Lembo et al.21	PsV	Italy	16	Prospective, single centre
Ryan et al.12	PsV	US	138	Retrospective, multicentre
Strober et al.24	PsV	US	152	Prospective, multicentre
Gedebjerg et al.20	PsV	Denmark	18	Prospective, single centre
Jokai et al.30	PsV	Hungary	38	Prospective, single centre
Shimauchi et al.28	PsV	Japan	28	Retrospective, single centre
Chiu et al.13	PsV	Taiwan	102	Prospective, single centre
Gulliver et al.14	PsV	Canada	45	Retrospective, single centre
Kanelleas et al.25	PsV	Greece	41	Prospective, single centre
Alivernini et al.36	PsA	Italy	12	Prospective, single centre
David et al.31	PsA	UK	128	Prospective, multicentre
Hellman et al.47	PsA	Sweden	20	Prospective, multicentre
Mascia et al.32	PsA	Italy	70	Prospective, single centre
Ørnbjerg et al.40	PsA	Multinational	7975	Retrospective, multicentre
Siebert et al.46	PsA	UK, US	1069	Retrospective, multicentre
Song et al.45	PsA	US	142	Prospective, multicentre
Ovejero-Benito et al.33	PsA	Spain	20	Prospective, single centre
Scrivo et al.41	PsA	Italy	149	Prospective, single centre
Muramatsu et al.48	PsA	Japan	29	Prospective, single centre
Ademowo et al.37	PsA	Ireland	10	Retrospective, single centre
Collins et al.38	PsA	Ireland	32	Prospective, multicentre
Fabris et al.34	PsA	Italy	74	Prospective, single centre
Murdaca et al.35	PsA	Italy	57	Prospective, single centre
Chandran et al.49	PsA	Canada	40	Prospective, single centre
Wagner et al.50	PsA	Multinational	100	Prospective, multicentre
Chimenti et al.51	PsA	Italy	55	Prospective, single centre
Marotta et al.52	PsA	Canada	24	Prospective, single centre
Pontifex et al.39	PsA	Ireland	25	Prospective, single centre
Pedersen et al.42	PsA	Denmark	17	Prospective, single centre
Gratacos et al.43	PsA	Spain	69	Prospective, multicentre
Kristensen et al.44	PsA	Sweden	261	Prospective, multicentre

PsA, psoriatic arthritis; PsV, psoriasis vulgaris; UK, United Kingdom; US, United States.