Author's response to reviews Title: Joint modeling of success and treatment discontinuation in in vitro fertilization programs: a retrospective cohort study Authors:

very clear. You say “Moreover, the well-known inverse-J relation between the woman’s age and chance of success was observed. On the contrary, risk of discontinuation globally increased as the woman’s age increased.” It might be clearer to say “The well-known inverse-J relation between the woman’s age and chance of success was observed, as expected. However, the risk of discontinuation globally increased as the woman’s age increased.” Authors’ response: The abstract has been modified as follows: The center influenced risk of treatment discontinuation but not chance of success. The well-known inverse-J relation between the woman’s age and chance of success was observed, as expected. Risk of discontinuation globally increased as the woman’s age increased. Population – If a woman moved to another centre would you know? Authors’ response: We don’t know if a woman moved to another center. This has been added in the material and methods section: Treatment discontinuation was defined as no treatment for at least two years in the IVF center (whatever the reason for discontinuation, e.g. maternal age, financial resources, move to another area, seeking IVF treatment elsewhere...) [8, 11, 12].