Table 1.
Information of all the studies included in the meta-analysis
| Study | Country/region | Population | Study design | GWAS | Cases | Controls | COHORT name | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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| First Author | Year | (YES/NO) | Total | FEMALE% | Total | FEMALE% | |||||
| 1a | Kochi et al. 1 [3] | 2010 | Japan | Japanese | Population based case-control | YES | 2301 | 81.40% | 3368 | 44.40% | NA |
| 1b | Kochi et al. 2 [3] | 2010 | Japan | Japanese | Population based case-control | NO | 3662 | 81.50% | 15873 | 34.10% | NA |
| 1c | Kochi et al. 3 [3] | 2010 | Japan | Japanese | Population based case-control | NO | 1106 | 79.20% | 1486 | 60.60% | NA |
| 2a | Stahl et al. 1 [4] | 2010 | USA/Canada/UK/North American/The Netherlands | European | Population based case-control | YES | 5539 | NA | 20169 | NA | NA |
| 2b | Stahl et al. 2 [4] | 2010 | USA/Canada/UK/North American/The Netherlands | European | Population based case-control | NO | 6768 | NA | 8806 | NA | NA |
| 3 | Hughes et al. [8] | 2010 | USA | African Americans | Population based case-control | NO | 556 | 83.88% | 804 | 83.88% | CLEAR |
| 4 | Teng et al. [6] | 2012 | Japan | Asian | Hospital based case-control | NO | 556 | 82% | 440 | 45% | TTSH |
| 5 | Prasad et al. [7] | 2012 | India | North Indians | Population based case-control | NO | 983 | NA | 1007 | NA | AIIMS, R & R |
| 6 | Chang et al. [5] | 2012 | Taiwan | Han Chinese | Hospital based case-control | NO | 400 | 81.79% | 680 | 49.93% | NA |
| 7a | Jiang et al. 1 [2] | 2014 | China | Han Chinese | Hospital based case-control | YES | 952 | NA | 943 | NA | NA |
| 7b | Jiang et al. 2 [2] | 2014 | China | Han Chinese | Population based case-control | NO | 2132 | NA | 2553 | NA | NA |
Case definition: Diagnosis was determined according to the revised criteria of the American College of Rheumatology 1987 criteria for Rheumatoid Arthritis.