It was interesting to read the letter by Drs Cabana et al regarding our article. The Scandinavian countries are very suitable for registry research. The unique personal identification number used in all population statistics in Sweden eliminates false registration.1 To our knowledge, studies of phototherapy are rare but are certainly of interest, even when they are preliminary case-control studies.
Berg P, Lindelöf B. Phototherapy in Neonates—Reply. Arch Pediatr Adolesc Med. 1998;152(8):818. doi: