The Development of Circadian Rhythms in Human Infants

* Class 7 used as reference group
† No cases fall into this category
NB ratio increase factor < 1 is actually represents a decrease
Description of variable factors on night time melatonin secretion
The following describes the factors which varied according to changes in the infant
care routine for that night or linked to the sleep environment of the infant analysed for
their effect on night time melatonin secretion.
For factors which changed throughout the period of the study as the infant got older;
such as use of sleeping bag or room/place of night time sleep, the mode category was
selected (most common for that infant during study period). For example, an infant
placed in its own room for 3 out of 4 nights of study was coded as having slept most
commonly in its own room as opposed to room sharing with his parents.
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