[1] Inst Recerca Sant Pau IR Sant Pau, Barcelona, Spain
[2] Univ Autonoma Barcelona, Dept Pediat Obstet Gynecol & Prevent Med, Barcelona, Spain
[3] Mayo Clin, Knowledge & Evaluat Res Unit, Dept Med, Rochester, MN 55905 USA
[4] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON, Canada
[5] McMaster Univ, Ctr Hlth Econ & Policy Anal, Hamilton, ON, Canada
[6] Univ Cincinnati, Div Gen Internal Med, Ctr Clin Effectiveness, Coll Med, Cincinnati, OH USA
[7] McMaster Univ, Dept Med, Hamilton, ON, Canada
[8] Ramon & Cajal Hosp, Dept Obstet & Gynecol, Madrid, Spain
[9] Alcala de Henares Univ, Fac Med, Madrid, Spain
[10] Ramon & Cajal Hosp, Dept Angiol & Vasc Surg, Madrid, Spain
[11] Hosp Sant Creu, Thrombosis & Hemostasis Unit, Barcelona, Spain
[12] Hosp Univ Vall dHebron, Hematol Serv, Hemostasis & Thrombosis Unit, Barcelona, Spain
[13] McMaster Univ, Dept Obstet & Gynecol, Hamilton, ON, Canada
[14] Mt Sinai Hosp, Dept Med, Lab Med & Pathobiol, Toronto, ON, Canada
[15] McMaster Univ, Sch Nursing, Hamilton, ON, Canada
[16] Serv Evaluat & Planning Canary Isl Hlth Serv SESCS, Canary Isl Hlth Serv SCS, Tenerife, Spain
[17] Network Res Chron Primary Care Hlth Promot RICAPPS, Tenerife, Spain
[18] Iberoamerican Cochrane Ctr, Barcelona, Spain
[19] CIBERESP, CIBER Epidemiol & Publ Hlth, Madrid, Spain