Perea-Bartolome et al. BMC Public Health 2011, 11:504 http://www.biomedcentral.com/1471-2458/11/504 over 65 years of age living in the city of Salamanca (Spain) and who participated in the cross-sectional study entitled “Sociosanitary needs of people over 65 years of age in the city of Salamanca”, financed by the regional health authorities (SOCIO673/01/08). Rando- mized sampling is contemplated, stratifying for health- care area. Power analysis The population universe was the city of Salamanca, with a total of 172,375 people. A 19.74% out of them (34,020) was 65 years old or more, while in rural empla- cement of the region the population older than 65 years old was a 30.25%. It was estimated that it would be a 16% at least. Taking an alpha risk of 0.05, a power of 20% and esti- mating the sum of prevalence of mild cognitive impair- ment plus dementia around a 16%, with a mistake of 4%, and taking into consideration the current population of 65 years old or older, it would be needed 320 partici- pants. Considering up to a 50% of loss for no response and according to similar studies, sample size was 480 participants. In this first study the population structure was taken into account as established from the individual health- care cards database of the Primary Care management authorities of Salamanca, with sampling stratified according to healthcare centers. The mentioned study was carried out through home interviews. Measurements The principal study measurements are the following: a) Sociodemographic variables: age, sex, educational level, marital status, family unit. b) Anthropometric variables and physical evaluation: body weight, height, waist circumference, blood pres- sure, heart rate, physical activity, lipid profile, blood glucose. c) Vascular risk factors: smoking, hypertension, dia- betes mellitus, dyslipidemia, obesity, alcohol intake. d) Cardiovascular disease: stroke, heart disease, neuro- pathy, retinopathy. e) Drug use (antihypertensive, antidiabetic, lipid-low- ering and antiplatelet drugs, psychoactive medication). f) Comorbidity. g) Functional grade will be evaluated in reference to daily life activities (both basic and instrumental), and data from an informant will be obtained. h) Neuropsychological assessment: assessment of the premorbid situation, attention-concentration, speech, logical memory, auditory-verbal learning, visioconstruc- tion memory, visual memory, executive function. Fol- lowing evaluation, the impairment phases will be classified, ranging from normality to the most severe phases of dementia. Page 4 of 8 Measurement instruments 1. Anthropometric measurements a) Height: the mean of two measurements using a wall meter (Seca 222), with the patient barefoot and in the erect standing position, and measuring to the nearest millimeter. Body mass index: weight (kg)/height (m)2. b) Waist circumference: the mean of three measure- ments, using a flexible measuring tape at waist level (at the midpoint between the last rib and the iliac crest), parallel to the floor, and measuring after inspiration. c) Weight: the mean of two measurements using a homologated and easily calibrated scale (Seca 770) with the patient barefoot and lightly clothed. The readings will be rounded to 100 grams. d) Clinical blood pressure (OMROM M-7): three mea- surements of systolic blood pressure (SBP) and diastolic blood pressure (DBP) will be made, calculating the mean of the last two readings, and using a validated sphygmomanometer (OMRON M7), following the recommendations of the European Society of Hyperten- sion. Pulse pressure (PP) will be estimated with the mean values of the second and third measurements. e) Physical activity: Physical activity will be estimated by the 7-day Physical Activity Recall (PAR)[44]. The PAR is a general measure of physical activity, which has been recognized as a valid and reliable tool in recent years, and is widely used in epidemiological, clinical and behavioral change studies. It consists of a semi-struc- tured interview (10-15 minutes) in which the partici- pants provide an estimate of the number of hours dedicated to physical or occupational activities requiring at least a moderate effort in the past 7 days. The cate- gories collected are: moderate, vigorous, and very vigor- ous physical activity. The dose of physical exercise will be estimated in METs/hour/week, and active persons will be taken to be those doing at least 30 minutes of moderate activity, 5 days a week, or at least 20 minutes of vigorous activity, 3 days a week. Persons not reaching this level of physical activity are regarded as sedentary. 2. Cardiovascular risk and stroke risk scales Estimated risk at 10 years will be calculated according to the Framingham risk scales for stroke and global cardio- vascular morbidity-mortality [22]. 3. Measurement of comorbidity The disorders established by Charlson in the original article published in 1987 [41] are: myocardial infarction; congestive heart failure; arterial hypertension; peripheral vascular disease; cerebrovascular disease; dementia; chronic pulmonary disease; connective tissue disease; peptic ulcer; mild, moderate or severe liver disease; dia- betes with or without organ damage; hemiplegia; leuke- mia; lymphoma; solid tumor with metastasis; AIDS; and moderate or severe kidney disease. After establishing patient comorbidity, each entity will be scored in a table