I am conducting research on the relationship between a person's birth order and later risk of obesity using data from several 1-year birth cohorts (e.g. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908417/).
A key challenge is that birth order is linked to other features such as maternal age, number of younger and/or older siblings, and birth spacing, that may also influence the outcome via different mechanisms. Further, any influence these things have on later obesity risk might be modified by the gender composition of the siblings, including the "index child" (the participant in the birth cohort).
For each index child, one could draw a timeline that showed all of the births in the family, with maternal age at the time variable.
I am trying to identify methods to analyze these kinds of data, where the order, timing, and nature of events might all be important. I am asking this question here because of the diversity of applications members work with - I expect someone has some immediate suggestions that will take me much longer to identify alone. Any nudges in the right direction(s) would be greatly appreciated.
Related question(s): How should I analyze data on birth intervals of women?