aPTT, activated partial thromboplastin time; NSI, nonspecific inhibitor (lupus anticoagulant); ACA PC, anticardiolipin antibody to phosphatidyl choline; ACA PS, anticardiolipin antibody to phosphatidyl serine; ACA PI, anticardiolipin antibody to phosphatidyl inositol; ACA PG, anticardiolipin antibody to phosphatidyl glycerol; ACA PE, anticardiolipin antibody to phosphatidyl ethanolamine; IVIG, intravenous immunoglobulin.

*Control arm for RR calculation.