Although data are available giving races of serious illness and causes
of mortality among children, there has been little documentation of p
atterns of normal childhood morbidity, particularly for specific age g
roups. To describe the health problems which are experienced by one-ye
ar-old children, information was taken from a larger study, the purppo
se of which was to compare illness patterns between groups of children
vaccinated against measles, mumps and rubella (MMR) at 13 months and
15 months of age. In this study, mothers were asked to keep a daily: d
iary documenting any health problems experienced by their child both b
efore and after their child was vaccinated. The data reported here wer
e taken from the diaries kept during the month preceding the MMR vacci
nation, giving a picture of the types of health problems encountered d
aily among this age group. We found that minor health complaints were
commonly reported for these children, and that there were marked diffe
rences in these reported health problems by sex of the child, season o
f the year, and type of child care setting.