does anyone have a good estimate of modafinil effects on birth control effectiveness?

I’ve seen lots of vague warnings that there might be problems but the closest I’ve seen to numbers is this study which seems to say something like:

  • there were 220 women of childbearing age in the study
  • 100 were on a “recommended contraceptive plan,” so that left 120 without
  • 3 women got pregnant despite being on hormonal contraceptives

which doesn’t sound particularly different from normal birth control effectiveness rates?

but there’s some missing data there and I might be misinterpreting because it wasn’t super clear/wasn’t actually trying to come up with an estimate