00563nas a2200193   4500000000100000000000100001008004100002100001200043700001700055700002100072700001400093700001500107700001700122700001500139245018300154300001100337490000700348022001400355       2016                            d1 aA. Boef1 aP. Souverein1 aJ. Vandenbroucke1 avan Vlieg1 aA. de Boer1 aS. le Cessie1 aO. Dekkers00aInstrumental variable analysis as a complementary analysis in studies of adverse effects: venous thromboembolism and second-generation versus third-generation oral contraceptives  a317-240 v25  a1053-8569