Authors' reply

EDITOR,—Kate Brooks and colleagues identify several points that were lacking from our review. We agree that, ideally, such details should be included in an article, but various limitations sometimes prevent this. We attempted to identify all the important, relevant studies that were available at the time. Because these were longitudinal studies and our initial searches in many languages did not identify any prospective studies reported in languages other than English, we thought it reasonable that the subsequent update over a period of about …