Is neonatal phototherapy associated with an increased risk for hospitalized childhood bronchial asthma?
This population-based register study examined if factors during the fetal and neonatal period influence the risk for the child to develop bronchial asthma (asthma). From the Swedish Hospital Discharge Register we identified children, born between 1987 and 1999, who had been hospitalized for asthma up to 2001. Thus, the outcome measure contains only hospitalized cases, not all children with asthma. Children younger than 2 yr at admission were excluded because of the uncertainty about the diagnosis of asthma in younger children. The remaining 14,803 children were compared with all children born the same years, recorded in the Swedish Medical Birth Registry, for information on pre- and perinatal characteristics. Odds ratios (ORs) were calculated with Mantel-Haenszel technique and 95% confidence intervals (CIs) with Miettinen’s test-based method. The presence of various maternal and neonatal confounders were identified and adjusted for in the analyses. The association between some known fa
