Table 2

 Mean cost of hospital inpatient stay by multiplicity

Age at admission*SingletonsTwinsHigher order multiple birthsp Value†
Mean costs95% CINo of childrenMean costs95% CINo of childrenMean costs95% CINo of children
Mean costs are per child in £ sterling.
*Only children alive at the start of the period were included in the cost estimates.
†Singletons, twins, and higher order multiple births were compared using multiple linear regression.
‡Mean costs were adjusted for duration of life as a categorical variable grouped in 0–7 days, 8–28 days, 29–365 days, and 366–1825 days.
Initial birth admission846841 to 85027042819311874 to 1987628436783085 to 4271185< 0.0001
Readmissions starting in:
    1st year414403 to 42726959616621541 to 1784616341573189 to 5125173< 0.0001
    2nd year104101 to 10726831811994 to 1456092541 to 1071670.30
    3rd year7471 to 772681848063 to 97608850447 to 960167< 0.0001
    4th year6764 to 702680997158 to 856088303 to 571670.74
    5th year6562 to 682680344941 to 5660851350 to 2891670.088
Entire study period‡15321516 to 154827042838263724 to 3929628481567559 to 8754185< 0.0001