TROMSO_SUBJECT_ID

Coding rule in SAS: 

retain SERIAL1 0;

SERIAL1 + 1;                                                                                                                                                                                              

SUBJECT_ID=SERIAL1;        

SENECA_SUBJECT_ID

The identification number in SENECA (variable ID) was constructed in the following way: code for country (position 1,2), serial number of the subject (position 3,4,5), code for sex (position 6), last two digits of the year of birth (position 7,8), code for town (position 9).

SUBJECT_ID was created from the first 5 positions of the SENECA variable ID.

EPIC_SUBJECT_ID

Coding rule in STATA: gen SUBJECT_ID = _n
Comment: It creates a variable with unique ID numbers starting from 1 and ending to n, which is the total number of individuals in the overall EPIC cohort