Nevertheless, interobserver reliability had not been assessed. We selected comparisons among three birth-year periods instead of individual birth years to supply a sufficiently large sample to control for confounding inside our analysis and to provide mortality estimates with greater accuracy. We performed post hoc subgroup analyses to judge potential differences in general and immaturity-related mortality because of the addition and attrition of centers as time passes, and we performed sensitivity analyses to judge the consequences of potential misclassification of deaths because of immaturity, the respiratory distress syndrome, or bronchopulmonary dysplasia . Additional analyses examined factors behind death that were challenging by either CNS damage or infection for which another primary cause was listed.21, 2015 – – Children who’ve their tonsils eliminated to take care of sleep apnea are more likely to suffer breathing problems than kids who’ve the procedure for other reasons, a new review shows. Researchers found that across 23 studies, about 9 % of children undergoing a tonsillectomy developed breathing problems during or soon after the procedure. But the risk was five times higher for kids with sleep apnea almost, versus other children.