THE CHILD GROUP USED AS A REFERENCE SYSTEM WHEN ANALYZING FREQUENCY OF MORBIDITY IN DAY-CARE-CENTERS

Morbidity frequency was analysed among children attending six day-care centres in a suburb of Stockholm, Sweden. Absence due to illness was calculated annually for each child and correlated with each child's ow n group. Thus a child was classified as ''often sick'' or ''mainly hea lthy'' in relation to the other children in the child's own group, con stituting a reference system. In almost every group a ''sick third'' w as found, whose absence due to illness was twice that of the rest of t he group. Children from families of lower social standing, those with a relatively large number of siblings and those living in poor social conditions were found to be among those most often reported as sick. I n such families, smoking was more commonplace. These parents more ofte n lived in a rented apartment than in a single detached owner house. M ultiple linear regression analysis revealed that young mothers and chi ldren with several siblings had the strongest correlation with absence due to illness of the proband child. Increasing maternal age revealed improvement vis-a-vis all socioeconomic parameters investigated, refl ecting an improvement in standing correlated to less sick children.