Dear all
I have a large dataset similar to this:
mother_number child_number GA nDate suggested var
1234567891 23456789 35 21 Feb 1975 .
1234567891 23456781 37 30 May 1978 35
1234567891 23456782 40 04 Oct 1982 37
1234567892 56789012 37 17 Mar 1976
1234567893 56489023 40 23 Sep 1985
1234567894 34567891 40 19 Nov 1977
1234567894 45567890 42 13 May 1979
From mother_number you can see that some women have more than one child (they
have the same identification number). GA is gestational age and nDate is date
of birth of the child. I need to generate another variable which indicates
gestational age of the previuos child. For example the first three lines are of
the same mother who gave birth to three children, the new variable would be
missing for child one (since it was the first child), 35 for child two and 37
for thild three.
Could anyone help me to solve this problem. Your help is highly appreciated.
Many Thanks
Ali
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