Second, patients may have been progressively lost to follow-up during the 1 year 24 weeks after delivery owing to unrecorded out-of-hospital deaths or emigration from California, and this would also have upwardly biased our estimates.
Second, patients may havebeen progressively lost to follow-up during the1 year 24 weeks after delivery owing to unrecordedout-of-hospital deaths or emigration fromCalifornia, and this would also have upwardlybiased our estimates.