Table 2.

Early RA observational cohorts with case-mix details

Cohort name or study first author	Study location	Data collection period	Centres (n)	Sample size	Symptom duration	Comorbidity	SEP	Smoking	Employment	Education
BARFOT	Sweden	1992–2006	6	2800	6 weeks to 12 months	✓	×	✓	✓	×
CAPEA	Germany	2010–13	118	1301	<6 months	✓	×	✓	×	✓
CATCH	Canada	2007 to present	21	2524	6 weeks to 12 months	✓	×	✓	✓	✓
CLEAR	USA	2001–05	5	300	<24 months	×	×	✓	✓	✓
CONAART	Argentina	2008–12	13	1045	<24 months	×	✓	✓	✓	✓
Cornec 2012	Brittany, France	1995–97	7	270	<12 months	×	×	×	×	×
DREAM	Netherlands	2006–12	6	589	<12 months	×	×	×	×	×
ERAN	UK and Ireland	2002–12	23	1236	<12 months	✓	✓	✓	✓	×
ERAS	England	1986–2001	9	1465	<24 months	✓	✓	✓	✓	✓
ESPOIR	France	2002–05	14	814	<6 months	✓	×	✓	✓	✓
‘French Cohort’	France	2003–04	5	191	<12 months	×	×	×	×	×
GLADAR	Latin America	2004–05	46	1093	<12 months	×	✓	×	×	✓
GREAT	South Africa	2005–08	2	171	<12 months	×	×	✓	✓	✓
Gremese 2013	Italy	2007–09	3	1795	<12 months	✓	×	×	✓	×
Jamal 2011	Canada	2003–06	15	204	<3 months	✓	×	×	×	✓
NHIRD	Taiwan	1996–2011	ND	51 476	ND	✓	×	×	×	×
Nijmegen Inception Cohort	Netherlands	1985–2009	2	1157	<12 months	✓	×	✓	×	×
NOAR	England	1990–2011	77	3666	<24 months	✓	✓	✓	✓	×
NOR-DMARD	Norway	2000 to 2012	5	4126	<5 years	✓	×	✓	×	✓
NOR-VEAC	Norway	2004–10	6	1118	<4 months	×	×	✓	×	✓
Olmstead County	USA	1955–2007	ND	813	ND	✓	×	✓	×	×
ORAR	Norway	1994–97	2	894	ND	×	×	×	×	✓
Pease 1999	England	1989 to ND	2	422	<24 months	×	×	×	×	×
RAMQ	Canada	2002–11	ND	11 365	ND	✓	×	×	✓	✓
Western Consortium	USA and Mexico	1993–2000	26	263	<14 months	×	×	×	×	×
SCQM database	Switzerland	1997–2011	ND	592	<12 months	✓	×	×	×	×
TIRA	Sweden	1996–98, 2006–08	10	636	6 weeks to 12 months	×	×	✓	✓	✓
United Healthcare Register	USA	2000–13	ND	195 433	ND	✓	×	✓	×	×
Van der Heijde 1992	Holland	ND	2	147	<12 months	×	×	×	×	✓
VERA	France	1998–2002	5	310	4 weeks to 6 months	×	×	✓	✓	✓
Wagner 2007	Austria, Hungary, and Slovenia	ND	7	172	Mean of 17 months	✓	✓	×	✓	✓
Westhoff 2007 and 2008	Germany	2000–01	54	1023	<12 months	✓	×	✓	×	✓
YEAR	England	1997–2009	14	1415	<24 months	×	×	×	×	×
Ziegalasch 2017	Sweden	ND	3	176	<12 months	×	×	×	×	×

Thirty-four unique cohorts from the literature search. Most cohorts are from more economically developed regions, with a broad range of centres and sample sizes. Case-mix consideration varied widely. The NOR-DMARD cohort collected data on patients with a symptom duration of up to 5 years. It has been presented in this review as there are a number of studies that have presented sub-analyses on patients with <2 years symptom duration. SEP: any time a scoring system or index was utilized; ND: not documented; BARFOT: Better Anti-Rheumatic PharmacOTherapy; CAPEA: Course And Prognosis of Early Arthritis; CATCH: Canadian Early Arthritis Cohort; CLEAR: Consortium for the Longitudinal Evaluation of African-Americans with Early RA; CONAART: Consorcio Argentino de Artritis Temprana; DREAM: Dutch Rheumatoid Arthritis Monitoring; ERAN: Early RA Network; ERAS: Early RA Study; ESPOIR: Étude et Suivi des Polyarthrites Indifférenciées Récentes; GLADAR: Grupo Latino Americano de Estudio de Artritis Reumatoide; GREAT: Gauteng Region Early Arthritis Trial; NHIRD: National Health Insurance Research Database; NOAR: Norfolk Arthritis Register; NOR-DMARD: Norwegian DMARD registry; NOR-VEAC: Norwegian Very Early Arthritis Cohort; ORAR: Oslo RA register; RAMQ: Régie de l’assurance maladie du Québec; SCQM: Swiss Clinical Quality Management; TIRA: Swedish Early Intervention in RA; VERA: Very Early RA; YEAR: Yorkshire Early Arthritis Register.