Methodology

Design Longitudinal observational study with 5 and 10 years follow-up

Participants A population-based, multistage sampling method was used to select men (75 ± 7 yr) and women (74 ± 7 yr), from the Republic of Cyprus, the Republic of Malta, Mallorca, Minorca (Spain) and the islands of Lesvos, Samothraki, Cephalonia, Crete, Corfu, Lemnos, Zakynthos, Siros, Naxos, Ikaria, Rhodes, Karpathos, Kassos, and Mykonos, in Greece. Individuals residing in assisted-living centers, as well as those with a clinical history of CVD or cancer were not included in the survey. The current active sample is about 2400 older people. The participation rate varied according to island, from 51% to 100%. A group of health scientists (i.e. physicians, dietitians and nurses) with experience in field investigation collected all the required information, using a quantitative questionnaire and standard procedures.

Ethics The collected data were confidential and the study followed the ethical considerations provided by the World Medical Association (52nd WMA General Assembly, Edinburgh, Scotland, October 2000). The Harokopio Institutional Review Board approved the design, procedures and aims of the study (16/19-12-2006). Moreover, the IRB of the University of Malta also approved the study. Before the interviews, participants were informed about the aims and procedures of the study and gave their consent.

Measurements Diabetes mellitus (type 2) was determined by fasting plasma glucose tests and was analyzed in accordance with the American Diabetes Association diagnostic criteria (i.e. fasting blood glucose levels greater than 125 mg/dl or use of special antidiabetic medication). Participants who had blood pressure levels ³140/90 mmHg or used antihypertensive medications were classified as hypertensive. Fasting blood lipid levels were also recorded and hypercholesterolemia was defined as total serum cholesterol levels >200 mg/dl or the use of lipid-lowering agents. HDL- and LDL-cholesterol as well as triglycerides were also recorded. Weight and height were measured to obtain body mass index (BMI) scores (in kg/m2). Obesity was defined as BMI > 29.9 kg/m2.

Socio-demographic The collected information also included basic demographic characteristics, such as age, gender, annual income and socializing. According to the Hellenic Ministry of Economics, the basic income (i.e. lowest level to meet basic needs) is 8000,00 € per person, but this has been modified for the other participating islands.

Social networks Participation in social networks, participation in social events and social groups, number of family members living together.

Lifestyle Current smokers were defined as those who smoked at least one cigarette per day or had stopped cigarette smoking during the past 12 months. Former smokers were defined as those who previously smoked, but had not done so for a year or more. The remaining participants were defined as rare or non-current smokers. Passive smokers were those exposed to environmental tobacco smoke (at the workplace, at home, in restaurants, etc.) for more than 30 minutes per day.

Dietary habits are assessed through a semi-quantitative, validated and reproducible food-frequency questionnaire. The frequency of consumption of various food groups and beverages (i.e. meat and products, fish and seafood, milk and other dairy products, fruits, vegetables, greens and salads, legumes, cereals, coffee and tea and soft-drinks) was assessed on a daily, weekly or monthly basis. To evaluate the level of adherence to the Mediterranean diet, the MedDietScore (possible range 0-55) was used.

Physical activity is evaluated using the shortened version of the self-reported International Physical Activity Questionnaire (IPAQ).

Lifestyle behaviours Hours of sleep per day, having mid-day naps (siesta), number of meals per day, preparation of food.

Health care system access Access to health care system, access to nutritionists / dietitians, use of drugs, drug suppliers.

Depression Symptoms of depression during the past month were assessed using the validated Greek translation of the shortened, self-report Geriatric Depression Scale (GDS).

  • For details about the methodology used please refer to the relevant papers.