Data management

Data were stored in an internet-accessible database especially developed for this study. Selected parts of the database were accessible by research nurses, research staff, logistics companies, and participants. Data were entered into the database under direct supervision of the research team.

Randomisation tables were stored in a safe under supervision of a third person at Wageningen University who was otherwise not involved in the trial. Treatment codes remained sealed for research staff and committee members of the Alpha Omega Trial during the course of the trial.

Overview of measurements

General information
Lifestyle and Health
Mental health
Clinical events

Questionnaires (in Dutch)

Lifestyle and Health (PDF)
Physical examination (PDF)
Food Frequency Questionnaire (PDF)
Well being (PDF)

Data dictionaries

General data dictionary
FFQ (English)
FFQ (Dutch)