Males 2,124 1,931 4,055 BMC Public Health 2008, 8:126 http://www.biomedcentral.com/1471-2458/8/126 Table 1: pSoBid target population by age and sex identified SIMD 2004 Females Both Sexes Number of subjects living in: 35–44 years 45–54 years 55–64 years Total 35–44 years 45–54 years 55–64 years Total 35–64 yrs 20% Least Deprived area* 5 % Most Deprived area* Total 2,169 1,482 3,651 2,024 949 2,973 6,317 4,362 2,278 1,849 10,679 4,127 2,335 1,366 3,701 2,074 1,091 3,165 6,687 4,306 13,004 8,668 10,993 21,672 * The most deprived sample was drawn from the category 5% most deprived by SIMD. The least deprived sample was drawn from subjects living in areas classed by SIMD as in the 20% least deprived category get population 12 groups of 300 each were selected according to strata defined by the combination of cate- gory, sex and age-group (35 to 44, 45 to 54, and 55 to 64 years) (Table 1) giving a total sampling frame of 3,600 subjects. As the study progressed, over-sampling of sub- jects from the most deprived group was required (due to the lower response rate) and the HIT section was approached to select randomly further potential subjects from the target population. GPs were able to exclude per- sons from the sample who had recently expired or who had a terminal illness. Due to the nature of the psycholog- ical questionnaires and cognitive assessment, only those who understood and spoke English were invited to partic- ipate in this pilot study. The eligibility of subjects was checked by GPs and Practice Managers before letters were sent. If the participant had had an illness which was likely to increase CRP levels acutely (e.g. urinary tract infection, upper respiratory tract infection, etc.) during the two weeks prior to his/her appointment this was recorded but assessments proceeded on the scheduled date. Recruitment Procedure Invitation letters to selected subjects were sent in batches of 150 every two weeks. Accompanying the letter was a form for the subject to return (in a reply paid envelope) recording their contact details and indicating their will- ingness to consider participation. Subjects who agreed to receive further information about the study were sent the pSoBid participant information booklet[40]. If there was no response after two weeks, a reminder was sent. The Research Nurse contacted those who received the partici- pant information booklet, and if after reading the infor- mation booklet they decided to participate in the study, they were invited to come for the first visit at their GP's clinic on a mutually agreed day and time (see Additional file 1 for flowchart). This process continued until approx- imately equal numbers for the 12 groups were recruited. Protocol The study comprised two visits, each lasting about an hour and a half to two hours. Arrangements were made for taxi transfers to and from the participants' homes. Posters advertising the study were displayed in GP Clinics and also in local community centres and libraries. Two free telephone numbers were set up one in the coordinat- ing centre and one in the Glasgow Royal Infirmary (GRI) where the research nurses were based. At Visit 1 the study was explained to participants and informed consent obtained. The visit involved comple- tion of lifestyle and psychology questionnaires, assess- ment of health status and measurement of blood pressure, pulse rate and indices of obesity (height, weight, hip, waist and mid thigh circumference). Lung function was measured by Forced Expiratory Volume in one second (FEV1) and Forced Vital Capacity (FVC). Questionnaires completed at this visit examined affective state and con- trol/coping i.e. the General Health Questionnaire[41] (which has been used previously in this context by other research groups[31,42]), the Generalised Self-Efficacy Scale[43], the Sense of Coherence Scale[44] and Beck Hopelessness Scale[45]. An appointment was made for the second visit (in the morning and fasting) to be carried out at GRI on a date convenient to the participant. At Visit 2, a fasting blood sample was taken to measure cholesterol, triglycerides, very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL), markers of diabetes and obesity (glu- cose, insulin, leptin and adiponectin), markers of inflam- mation and clotting [C-reactive protein (CRP); inerleukin-6, (IL6); fibrinogen, D dimer; tissue plasmino- gen activator (tPA) antigen], and markers of endothelial dysfunction [Intercellular Adhesion Molecule (ICAM); von Willebrand Factor (vWF)]. Then, after breakfast, par- ticipants completed further psychological and cognitive function tests, and underwent ultrasound assessment of carotid intima media thickness and plaque count. Previ- ous research has shown an association between eating breakfast and mood and performance, with the effects due in part to experimental manipulation of the normal morning routine[46,47]. In this study as far as possible breakfast was provided according to an individual's nor- mal routine (or abstinence, if relevant), so that any effects Page 4 of 11 (page number not for citation purposes)