Table 1.

Main characteristics of the 16 cohort studies selected for systematic literature review

Study, year	Source	Incident PsA	Total	PsO duration	Follow-up (years)	Factor(s) of interest	NOS score
Li, 2012	NHSII registry	146	556	NA	NA	Obesity	5
Li, 2012	NHSII registry	157	581	NA	4.1	Smoking	5
Love, 2012	Claim DB (THIN)	976	75,395	NA	4.9	Obesity	7
Wilson, 2009	Claim DB	57	1593	NA	13.1	Nail dystrophy, type and site of psoriasis	7
Abji, 2016	Outpatients	52	620		3.1	Serum biomarker	7
Eder, 2016	Toronto Psoriasis cohort registry	51	464	16.4 ± 14.4	4.1	Nail pitting, obesity, smoking, and alcohol habits, family history of PsA	8
Faustini, 2016	Outpatients	12	41	15.2 ± 15.4	1.2	Inflammation and structural damage detected by imaging	7
Eder, 2017	Toronto Psoriasis cohort registry	57	410	16.5 ± 2.6	3.8	Musculoskeletal complaints	8
Lewinson, 2017	Claim DB (THIN)	1466	73,447	NA	5.1	Depression, obesity, smoking, and alcohol habits	8
Nguyen, 2017	Claim DB (THIN)	4569	225,213	NA	7.0	Smoking habits	7
Thorarensen, 2017	Claim DB (THIN)	1010	70,646	12.2 ± 12.0	6.0	Trauma	8
Egeberg, 2018	Claim DB (DNPR)	1269	10,011	7.7 ± 5.1	NA	PsO severity	7
Elnady, 2019	Outpatients	9	104	8.7 ± 7.17	2.0	Inflammation and structural damage detected by imaging	6
Zabotti, 2019	Outpatients	6	102	NA	1.2	Inflammation and structural damage detected by imaging, musculoskeletal complaints, family history of PsA	7
Green, 2020	Claim DB (CRPD)	1409	90,189	5.71 ± 4.1	5.8	Obesity, smoking, and alcohol habits	8
Simon, 2020	Outpatients	24	114	15.8 + 14.8	2.4	Nail involvement, inflammation, and structural damage detected by imaging, musculoskeletal complaints	8

CRPD Clinical Practice Research Datalink, DB database, DNPR Danish National Patient Register, NA not available, THIN The Health Improvement Network