All Lifelines participants have signed an informed consent (IC) form.

For adults, the IC contains the following statements:

• The undersigned agrees to participate in the Lifelines study aimed at unravelling the interaction between genetic and environmental factors in the genesis and the evolution of a number of different common chronic diseases associated with aging such as but not limited to, diabetes, cardiovascular disease, lung disease and depressions. I agree that within this study a part of the research questions are as yet to be formulated. With the knowledge gained in this study, it is hoped to contribute to healthier ageing.
• I agree that participation in this study means that over an extended period of time, I will complete extensive questionnaires about my health and living habits, and that every 4‐5 years I will be visiting the general practitioner (GP) or research centre for a number of measurements. At some visits 75 ml or less blood will be collected and I will be asked to provide a urine sample. The blood and the urine will be frozen for later analyses, which are important for the knowledge about chronic diseases in old age. I agree that at some point in time partners, parents and children (if any) will be invited to participate in the study.
• I agree that the individual results arising from the LifeLines study which are of interest to a GP, such as blood pressure, blood values, lung function, ECG, cholesterol, blood glucose levels and the results of the MINI interview, will be provided to my GP.
• I agree that the investigators can use data (hospital admission, diagnosis, treatment and medication) from my medical file from my GP or from hospitals, nursing homes or other institutions where I have received medical care, as well as data in registrations in so far as they concern the objectives of the Lifelines study (central bureau of statistics, the national registration of causes of death). The investigators will treat my data confidentially and all rules defined in the data protection act will be adhered to.
• I agree that the investigators of Lifelines approach me with additional questions and examinations, which are important for the understanding of chronic diseases. I acknowledge that the body materials and the data collected by LifeLines belong to Lifelines and that I have no rights to the research performed on it.
• By signing this declaration I retain the right at all times, also without reason, to decline further participation in the study. This does not affect my further treatment by my GP and by the UMCG.

For children between 0-11 years old, the same statements were included in the IC but written for parents who signed on behalf of their child.
For children between 12-17 years old, the same statements were included in the IC was written for both the child and his/her parents, and the child and at least one parent signed the IC.