Q:

"we used baseline from a study" vs. "we used the baseline from a study"

I understand the rules about the usage of "the" in English Grammar Today on Cambridge Dictionary.
From a post

For this longitudinal cohort study, we used baseline and 2-year follow-up data from the Netherlands Study of Depression and Anxiety (NESDA) and the Netherlands Study of Depression in Older Persons (NESDO) cohorts.

"Baseline" is not general, should "the" be used here? If yes, how about "2-year follow-up data"?

For this longitudinal cohort study, we used the baseline ...

A:

I cannot be sure what the authors intended; it is not a cleverly drafted sentence (or maybe it is a very cleverly drafted sentence). If they used only some of the data, then they clearly cannot say "the." So are we to assume that they ignored some of the data while trying to imply that they used it all? 
Most likely they meant something like "all relevant data contained in the baseline and two-year follow-up studies of the ... But when people write ambiguously, either purposefully or negligently, they have no one to blame but themselves if the words are construed against them.

