Table 2.

Summary characteristics of studies, overall and by type of biomarker

	Type of biomarker evaluated							Totals, all biomarkers
Characteristic	Genomic	Transcriptomic	Proteomic	Metabolomic	Microbiomic	Cellular	Mixed
No. of included studies (% of total)	41 (23%)	7 (4%)	88 (49%)	8 (4%)	1 (1%)	7 (4%)	29 (16%)	181
Mean/median biomarkers per study	20/3	16/1	8/2	53/1	N/A	3/2	9/5	13/2
Mean/median no. of psoriasis patients	1305/398	76/73	235/74	89/88	N/A	161/96	130/72	371/92
No. of studies evaluated further a (% of studies in category)	19 (46%)	2 (29%)	28 (31%)	3 (38%)	0 (0%)	3 (43%)	6 (21%)	61 (34%)
Candidate biomarkers (% of total)	10 (45%)	0	10 (45%)	2 (9%)	0	0	0	22

^a Studies which were eligible for further data extraction and quality assessment.