TY - STAND AU - A. Boef AU - P. Souverein AU - J. Vandenbroucke AU - van Vlieg AU - A. de Boer AU - S. le Cessie AU - O. Dekkers BT - Pharmacoepidemiol Drug Saf DO - 10.1002/pds.3956 M1 - 3 PY - 2016 SP - 317 EP - 24 T2 - Pharmacoepidemiol Drug Saf TI - Instrumental variable analysis as a complementary analysis in studies of adverse effects: venous thromboembolism and second-generation versus third-generation oral contraceptives VL - 25 SN - 1053-8569 ER -