title: New study shows OCs don't reduce rheumatoid arthritis risk.
mesh_terms: D000569:Americas; D002908:Chronic Disease; D003267:Contraception; D003270:Contraceptive Agents; D003271:Contraceptive Agents, Female; D003276:Contraceptives, Oral; D019049:Developed Countries; D003906:Developing Countries; D004194:Disease; D005193:Family Planning Services; D009656:North America; D012106:Research; D012107:Research Design; D014481:United States
chemical_list: D003270:Contraceptive Agents; D003271:Contraceptive Agents, Female; D003276:Contraceptives, Oral
keywords: Americas; Chronic Diseases; Comparative Studies; Contraception--beneficial effects; Contraceptive Agents, Female--beneficial effects; Contraceptive Agents--beneficial effects; Contraceptive Methods--beneficial effects; Control Groups; Developed Countries; Developing Countries; Diseases; Family Planning; Matched Groups; North America; Northern America; Oral Contraceptives--beneficial effects; Research Methodology; Studies; United States