ADAB refactoring

[shajoezhu]

From Qi:

Here is my suggestion.

Key variables:
STUDYID, USUBJID, ARM, ACTARM, (exist in ADSL)
VISIT, VISITDY, ISTPT, AVAL, AVALC, AVALU, PARAM, PARAMCD, PARCAT1, NRELTM1, RELTMU, ADABLFL, ADAPBLFL, ABLFL.

The PARAM and PARAMCD are quite consistent across all the studies. ADA data were collected at the same time with the pre-dose PK. We need to have ADPC and ADAB aligned, this is required in the ADA standard table 3.

Below is the dummy example. PARAM = "Antibody titer units" and "ADA interpreted per sample result" are VISIT-level variables, rest are subject-level variables which are derived based the "Antibody titer units" or "ADA interpreted per sample result".

Please let me know if you have any questions.

Thanks,
Qi

Originally posted by @qiliu1013 in #143 (comment)

suggestion and todo

The adab table is a mixed long table, where some rows are subject level info will be unique, and some rows will be observational data.

Suggest to program a function for per patient simulation, then lapply to all patients, and concatenate the dataframes.