Ancillary studies represent an important part of 3C-Study scientific output. They can be initiated either by investigators belonging to the 3C-Study founding teams (See Investigators, Study Sites, Collaborating Centres and Working Groups) or by outside investigators. Proposals of new ancillary studies by outside investigators are encouraged. These studies can either use data and stored biological specimens available in the 3C-Study, or involve the collection of new data from all participants or specific subgroups.
The following main topics have already been at least partly addressed in ancillary studies: Risk factors for clinical and subclinical vascular diseases in the elderly (coronary heart disease, carotid atherosclerosis and stroke); Relationship of nutrition with cognitive decline, dementia and vascular diseases; Diabetes; Renal diseases; Metabolic syndrome; Depression; Sleep disorders; Neurological diseases in the elderly; Hormonal replacement therapy in elderly women; Walking and its relationship with subsequent events; Disability and frailty; Medication use. Several ancillary studies are currently in progress.
The review process for proposals received from outside investigators is described in the following section. Ancillary study policy also deals with agreements on the transmission of data and materials (before the start of the study) and the review of manuscript proposals after the study has been concluded.
Ancillary Study Policy
Investigators unaffiliated with any of the 3C-Study founding teams (See Investigators, Study Sites, Collaborating Centres and Working Groups) are welcome to propose ancillary studies. Non-3C Study investigators are encouraged to work in collaboration with a senior investigator from one of the 3C-Study founding teams. The 3C-Study correspondent investigator can either be contacted directly by an investigator submitting an ancillary study, or can be designated by the 3C-Study Steering Committee.
Ancillary study proposals must be sent to the Coordinating Centre (E3C.U708@inserm.fr) for review by the Steering Committee. These proposals must be sent to the 3C Steering Committee at least 8 weeks before submission to a funding institution; longer review time can be expected for ancillary studies funded by for-profit organizations. The Ancillary study application form and other documents (Data and Material Distribution Agreement...) required to obtain approval of the proposal by the Steering Committee or to publish the results of the study (Manuscript proposal form) can be downloaded from the 3C-Study website.
An agreement with the Coordinating Centre on the costs of carrying out the ancillary study is also required for Steering Committee approval. Costs to be be taken into account are those involved in data collection and, when applicable, biological samples transmission.
A specific agreement may be required for ancillary studies that involve transmission of genetic material (See Genetic Studies).
IMPORTANT: Only a limited number of subsets of the 3C database (i.e. limited number of variables) can be transmitted to non-3C investigators. For ancillary studies that request a large number subsets or the entire database, the data analysis can be carried out by the data management centre, or by a 3C team designated by the Steering Committee in close collaboration with the initiating investigators.