Data Collection
Data were collected in two distinct periods, the first being from April to August 2000 and the second from January 2005 to May 2006. Additionally, survival data have been collected from April 2000 to April 2010. Attempts were made to contact all the individuals of the target group through house visits, visits to senior day centres, and contact with hospital administrators and practising physicians. A specially trained health visitor (registered nurse) and two physicians who had served in the local health center interviewed the participants during the first and second period respectively, using a standardized, pre-coded questionnaire.
The interview of both study periods covered sociodemographic and anthropometric characteristics, as well as medical history. They also included an assessment of the 15-item Geriatric Depression Scale (GDS-15) and the Mini Mental State Examination (MMSE) scale, both being translated into Greek and validated in a Greek population by previous researchers. The second period study included additional data on stressful events history, data on lifestyle and health related habits, as well as the assessment of a suicidal ideation scale and a Food Frequency Questionnaire. Blood and saliva samples have also been collected for the participants of the second period study [and serum samples have been frozen at -70°C and stored for further determinations]. The data collected as well as the questionnaires used are presented in detail below: