ICPC is produced from WONCA. In the 5th WONCA world conference in Melborn they decided to develop the classification for primary care. It is the start of Wonca International Classification Committee (WICC).
Informatics is the one of most important tool for modern epidemiology.
Epidemiological study starts from 1 and 2. Multi institutional data should be in standardized data format. Most well used format is HL7.
It is very easy to start 3 or 4 process if all your data are in HL7 format. In other case, you have to consider sign analysis or discrete variable analysis.
In big data analysis, you have to take care about false positive because according to the data size, practical number of false positive increases linearly.