Dear Statalisters,

I am using a longitudinall dataset in which my main outcome is "QI score" (measured in 10 consecutive years) and the principal covariate is "overall stress score" which was measured during 1, 8 and 9 year (irregular spaced in time measurements).


Objectives : 1# I'd to assess if the stress level during the first year of study is predictive of the QI score at the 8 and 9th year (with adjustment on sex, age and socioeconomic level).
2# I would to assess if the IQ score of the first year may influence the IQ of the next years (from 2 to 10)

I was looking through the bibliography and I found the concept of Lagged response models. However, I am not understanding how to run this model with considering the inequally spaced measurement of the "overall stress score". AND, also to test the same model without considering this inequally spaces in time.

I really appreciate your support.

Best regards,

I am using STATA 14.2