Reduction in missed school days and improvement in parent activity participation in children with juvenile idiopathic arthritis treated with abatacept by Ruperto N, Lovell DJ, Li T, Paz E, Horneff G, Huppertz HI, Deslandre CJ, Minden K, Punaro M, Nunez AF, Sigal L, Block A, Covucci A, Martini A, Giannini EH